Infectious Diseases Flashcards by Grazielle Verzosa

Criteria for Fever of Unknown Origin (FUO)

rectal T ≥ 38° C
cause could not be identified
3 weeks - OPD
1 week - hospital

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FUO in Neonates

7% risk of having serious bacterial infection

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FUO at 1-3 mos.

pyelonephritis - most common

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FUO at 3 mos. - 3 y.o.

viral infection

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_____ are connective tissue diseases most commonly associated with FUO.

JIA, SLE

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Empirical treatment for FUO should be avoided except in _____.

anti-TB drugs for the critically ill

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_____ is an aerobic, G (+), coagulase (+) bacteria that grows in pairs or clusters.

Staphylococcus aureus

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_____ is the most common cause of pyogenic infection of the skin and soft tissue

S. aureus

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Adhesion of S. aureus to mucosal cells is mediated by _____ in the cell wall.

teichoic acid

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Staphylococci produce a _____ which may interfere with opsonophagocytosis.

slime layer

loose polysaccharide capsule

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_____ is present in S. aureus and absorbs serum Ig, preventing antibacterial antibodies from acting as opsonins.

Protein A

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Enzymes Elaborated by Staphylococci

catalase

penicillinase or β-lactamase

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_____ is a protein than S. aureus combines with phospholipid in the leukocytic cell membrane, producing increased permeability and eventual death of the cell.

Panton-Valentine Leukocidin (PVL)

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S. aureus with _____ is associated with more severe and invasive skin disease, pneumonia and osteomyelitis.

Panton-Valentine Leukocidin (PVL)

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_____ in S. aureus produce dermatologic manifestations by splitting the desmosome and altering the intracellular matrix in the stratum granulosum.

Exfoliatins A and B

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S. aureus can produce _____ distinct enterotoxins.

≥ 20

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_____ are the most common causes of food poisoning from S. aureus.

Enterotoxin A and B

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_____ is associated with TSS related to menstruation and focal staphylococcal infection.

Toxic Shock Syndrome Toxin 1 (TSST-1)

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_____ is a superantigen from S. aureus that induces the production of IL-1 and TNF, resulting in hypotension, fever and multisystem involvement.

Toxic Shock Syndrome Toxin 1 (TSST-1)

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An altered _____ is responsible for the methicillin resistance of MRSA isolates.

PBP-2A

protein binding proteins

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_____ that complicates viral croup may be caused by S. aureus.

Membranous Tracheitis

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S. aureus often causes _____ that may be associated with empyem, pneumatocoeles, pyopneumothorax and bronchopleural fistulas.

necrotizing pneumonitis

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Localized staphylococcal abscesses in muscle is called _____.

pyomyositis.

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_____ is the most common cause of osteomyelitis and suppurative arthritis in children.

S. aureus

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_____ is an acute and potentially severe illness caharcterized by fever, hypotension, erythematous rash with dezquamation of the hands and feet, vomiting, diarrhea, neurologic abnormalities, myalgia, conjuctival hyperemia, and strawberry tongue.

Toxic Shock Syndrome (TSS)

TSS occurs most commonly in _____

menstruating women 15-25 y.o.

Diagnostic Criteria of Staphylococcal TSS

Major Criteria (all are required) - acute fever (> 38.8°C) - hypotension - rash (erythroderma with convalescent desquamation) Minor Criteria (≥ 3) - thrombocytopenia (≤ 100,000) - mucus membrane inflammation - vomiting, diarrhea - liver abnormalities - renal abnormalities - muscle abnormalities - CNS abnormalities

``` Diagnostic Criteria of Staphylococcal TSS: Major Criteria (all are required) ```

acute fever (> 38.8°C) hypotension rash (erythroderma with convalescent desquamation)

``` Diagnostic Criteria of Staphylococcal TSS: Minor Criteria (≥ 3) ```

``` thrombocytopenia (≤ 100,000) mucus membrane inflammation vomiting, diarrhea liver abnormalities renal abnormalities muscle abnormalities CNS abnormalities ```

Toxic Shock Syndrome (TSS) Treatment

β-lactamase-resistant antistaphylococcal antibiotic (Nafcillin, Oxacillin, 1st generation Cephalosporin) Vancomycin (MRSA) Clindamycin (reduces toxin production)

_____ infections are common in patients with indwelling foreign devices.

Coagulase Negative Staphylococci (CoNS)

_____ are the most common cause of nosocomial infection, especially in NICU.

CoNS

_____ is the most common and persistent species of CoNS.

S. epidermidis

CoNS, specifically S. epidermidis, are the most common cause of nosocomial bacteremia associated with _____.

central venous catheter

CoNS is a common cause of _____ endocarditis.

prosthetic valve.

_____ is the most common pathogen found in CSF shunt meningitis.

CoNS

_____ is a common cause of primary UTI in sexually active females.

S. saprophyticus

True bacteremia with CoNS is considered when there is _____.

growth within 24 hours ≥ 2 cultures with same strain both peripheral and line sites are (+)

Most CoNS strains are resistant to _____.

Methicillin

_____ is a G (+), lancet-shaped, bile soluble, optochin sensitive, polysaccharide encapsulated diplococcus, occurring as individual cocci or in chains.

Streptococcus pneumoniae

_____ is the most common cause of bacteremia, bacterial pneumonia, otitis media and bacterial meningitis in children.

S. pneumoniae

Encapsulated strains cause most serious diseases because _____ impede phagocytosis.

capsular polysaccharides

S. pneumoniae is a common cause of secondary bacterial pneumonia in children with _____.

influenza

Patients with _____ are susceptible to encapsulated organisms because of deficient opsonization and clearance of bacteria.

asplenia

A _____ should be performed when a pneumococcus is resistant to Erythromycin but sensitive to Clindamycin.

D-test | induce Clindamycin resistance

Immunologic responsiveness and efficacy following administration of pneumococcal polysaccharide vaccines is unpredicaatable in children _____.

< 2 y.o.

_____ prophylaxis is recommended for children at high risk of invasive pneumococcal disease, including children with asplenia or sickle cell disease.

Penicillin

Group A Streptococcus (GAS) is also known as _____.

Streptococcus pyogenes

_____ causes distinct clinical entities such as scarlet fever and erysipelas.

S. pyogenes (GAS)

S. pyogenes (GAS) causes 2 nonsuppurative complications:

Rheumatic Fever | Acute Glomerulonephritis

_____ are G (+) coccoid-shaped bacteria that grow in chains.

S. pyogenes (GAS)

Virulence of S. pyogenes (GAS) depends on the _____ which resists phagocytosis.

M protein

Streptococcal pyoderma occurs most frequently in _____ temperatures.

warmer

Streptococcal _____ are responsible for the rash of scarlet fever.

pyrogenic exotoxins A, B and C

_____ is an URTI associated with a characteristic rash which begins around the neck and spreads over the trunk and extremities.

Scarlet Fever

The rash of scarlet fever appears within _____ after onset of symptoms.

24-48 hours

After _____, the rash of scarlet fever begins to fade and is followed by desquamation starting with the _____.

3-4 days | face progressing to the trunk

A diffuse, finely papular rash with erythematous eruption which blanches on pressure is characteristic of _____.

Scarlet Fever

A _____ tongue is usually seen in Scarlet Fever.

strawberry tongue

_____ is a GAS infection which involves the deeper layer of skin and connective tissue with a sharply defined slightly elevated border.

Erysipelas

The gold standard for the confirmation of GAS pharyngitis is _____.

throat swab culture on a sheep blood agar plate

S. pyogenes (GAS) is very sensitive to _____.

Penicillin

_____ is a superficial S. pyogenes (GAS) skin infection that appears as an erythematous papulovesicular lesion which becomes purulent and covered with an amber-colored crust which appears to be stuck onto the skin.

Non-bullous Impetigo

_____ is a S. pyogenes (GAS) skin infection with flaccid, transparent bullae < 3 cm in diameter.

Bullous Impetigo

S. pyogenes (GAS) is a common cause of vaginitis in _____.

prepubertal girls

Criteria for Streptococcal TSS

Hypotension plus ≥ 2 of the ff.: - renal impairment - coagulopathy - hepatic involvement - adult respiratory distress syndrome - generalized erythematous macular rash - soft-tissue necrosis

Severe Invasive GAS Infections

Streptococcal TSS | Necrotizing Fasciitis

_____ is characterzized by the onset of acute arthritis following an episode of GAS pharyngitis in a patient whose illness does not fulfill the Jones criteria.

Poststreptococcal Reactive Arthritis (PSRA)

_____ is a group of neuropsychiatric disorders (OCD, tic disorder, Tourette Syndrome) for which a possible relationship with GAS infections has been hypothesized.

Pediatric Autoimmune Neuropsychiatric Disorders Associated with S. Pyogenes (PANDAS)

When therapy against GAS is given within _____ of onset, acute rheumatic fever is prevented.

9 days

_____ is the most common form of acquired heart disease.

Rheumatic Heart Disease

_____ is most closely associated with the incidence of acute rheumatic fever.

Crowding

A property of GAS that has been associated with rheumatogenicity is the formation of _____.

highly mucoid colonies

Children _____ are at greatest risk for GAS pharyngitis.

5-15 y.o.

Cytotoxic Theory of the Pathogenesis of ARF and RHD

``` GAS toxin Streptolysin O (direct cytotoxic effect on cells) ```

Immunologic Theory of the Pathogenesis of ARF and RHD

common antigenic determinants shared between GAS and mammalian tissue (M protein ↔ tropomyosin, myosin)

Criteria for Acute Rheumatic Fever

``` Jones Criteria 5 Major Criteria - migratory polyarthritis - carditis - subcutaneous nodules - erythema marginatum - Sydenham chorea ``` 4 Minor Criteria - arthralgia - fever - elevated ESR and CRP - prolonged PR interval *2 major, 1 major + 2 minor

_____ is the most serious manifestation of ARF.

Carditis

_____ is a universal finding in ARF.

Endocarditis (Valvulitis)

_____ is the earliest manifestation of ARF and has an inverse relationship with the severity of cardiac involvement.

Migratory Polyarthritis

In ARF< there is a correlation between the presence of subcutaneous nodules and significant _____.

Rheumatic Heart Disease

Clinical Maneuvers for Chorea

- Milkmaid's Grip (irregular contractions while squeezing examiner's hand) - spooning and pronation of hands when extended - wormian darting movements of tongue on protrusion - handwriting

Absolute Requirements for Evidence of GAS Infection

(+) throat culture or rapid streprococcal antigen test | elevated or increasing streptococcal antibody titer

ARF without adherence to Jones Criteria can be made when there is _____

Chorea as the only manifestation Indolent Carditis as the only manifestation Recurrent ARF

Treatment for ARF

Oral Penicillin or Erythromicin x 10 days | IM Benzathine Penicillin as single dose

Anti-inflammatory agents should be withheld if arthralgia or atypical arthritis is the only clinical manifestation. _____ may be used instead

Acetaminophen

ARF patients with typical migratory polyarthritis and those with carditis without cardiomegaly or CHF should be given _____

oral salicylates Aspirin: 100 mkday q6 x 3-5 days then 75 mkday q6 x 4 weeks

ARF patients with carditis and cardiomegaly or CHF should be given _____.

corticosteroids Prednisone: 2 mkday q6 x 2-3 weeks then tapered by 5 mg/day ever 2-3 days

_____ is the treatment of choice for Sydenham chorea.

Phenobarbital 16-32 mg q6-8 PO

_____ is the regimen of choice for ARF antibiotic prophyhlaxis.

IM Benzathine Penicillin every 4 weeks 600,000 IU - ≤ 60 lbs 1.2 M IU - > 60 lbs

ARF Antibiotic Prophyhlaxis: | RF without carditis

5 years or until 21 y.o.

ARF Antibiotic Prophyhlaxis: | RF with carditis but without residual heart disease

10 years or until 21 y.o.

ARF Antibiotic Prophyhlaxis: | RF with carditis and residual heart disease

10 years or until 40 y.o. or lifelong

Group B Streptococcus (GBS) is also known as _____.

Steptococcus agalactiae

S. agalactiae (GBS) is a major cause of _____.

neonatal sepsis

_____ are facultative anaerobic G (+) cocci that form chains or diplococci in broth and small gray-white colonies on solid medium.

S. agalactiae (GBS)

Presumptive Identification of S. agalactiae (GBS)

β-hemolysis on blood agar resistance to Bacitracin and TMP-SMX lack of hydrolysis of bile esculin elaboration of CAMP factor

Early Onset GBS Disease: | Age at Onset

0-6 days

Early Onset GBS Disease: | Increased Risk after Obstetric Complication

Early Onset GBS Disease: | Clinical Manifestations

sepsis, pneumonia, meningitis

Early Onset GBS Disease: | Common Serotypes

Ia, Ib, II, III, V

Early Onset GBS Disease: | Case Fatality Rate

4.7%

Late Onset GBS Disease: | Age at Onset

7-90 days

Late Onset GBS Disease: | Increased Risk after Obstetric Complications

Late Onset GBS Disease: | Clinical Manifestations

bacteremia, meningitis, focal infections

Late Onset GBS Disease: | Common Serotypes

III

Late Onset GBS Disease: | Case Fatality Rate

2.8%

GBS Treatment: | Bacteremia without a Focus

10 days

GBS Treatment: | Meningitis

2-3 weeks

GBS Treatment: | Ventriculitis

4 weeks

GBS Treatment: | Septic Arthritis or Osteomyelitis

3-4 weeks

A major risk factor for the development of early-onset GBS infection is _____.

maternal vaginal or rectal colonization by GBS

The foremost risk factor implicated in the pathophysiology of invasive GB disease is the _____.

type-specific capsular polysaccharide

The _____ component of the GBS capsular polysaccharide prevents activation of the alternative pathway in the absence of type-specific antibody.

sialic acid

GBS Virulence Factors: | adhesion to host cells

GBS Surface Protein

GBS Virulence Factors: | inhibit the recruitment of PMN cells

C5a Peptidase

GBS Virulence Factors: | associated with cell injury

β-Hemolysin

GBS Virulence Factors: | spreading factor in host tissue

Hyaluronidase

The _____ of the GBS cell wall are potent inducers of the TNF-α release.

Group B Antigen | Peptidoglycan Component

Invasive GBS disease in children beyond early infancy is uncommon and manifests as _____.

bacteremia | endocarditis

Severe apnea, easly onset of shock, abnormalities in WBC count and greater lung compliance may indicate infants with _____ rather than RDS.

GBS disease

_____ is the recommended treatment for GBS disease.

Penicillin

Interruption of neonatal colonization is achievable if antibiotics are given to the mother during _____.

labor

Intrapartum antibiotics should be given to women with _____.

``` (+) prenatal screening GBS bacteriuria previous infant with GBS disease unknown culture status delivered prematurely PROM (> 18 hours) intrapartum fever (≥ 38°C) ```

_____ are G (+), catalase (-) facultatice anaerobes that grow in pairs or short chains.

Enterococci

_____ accounts for 80% of enterococcal infections.

E. faecalis

Diptheria is an acute toxic infection caused by _____.

Corynebacterium diphtheriae

_____ are aerobic, nonencapsulated, non-spore-forming, mostly non-motile, pleomorphic, G (+) bacilli.

Corynebacteria

The virulence of C. diphtheriae lies in its ability to produce the potent _____ which inhibits protein synthesis and causes local tissue necrosis.

65kd polypeptide

Within the first few days of diphtheria, a dense necrotic coagulum of organisms, epithelial cells, fibrin, leukocytes, and erythrocytes forms and becomes a gray-brown leather-like adherent _____.

psudomembrane

The primary focus of respiratory tract diphtheria is the _____.

tonsils or pharynx

_____ causes shallow ulceration of the external nares and upper lip in infants as well as soft tissue edema creating a bull-neck appearance.

respiratory tract diphtheria

_____ presents as a superficial, ecthymic, non-healing ulcer with a gray-brown membrane.

cutaneous diphtheria

_____ causes 50-60% of deaths from diphtheria.

Toxic Cardiomyopathy

Toxic cardiomyopathy in diphteria presents as tachycardia which is _____.

disproportionate to fever

Cranial neuropathies caused by diphtheria occur in the _____ leading to _____.

5th week | oculomotor and ciliary paralysis

In diphtheria, muscle weakness progresses _____.

distal → proximal

_____ is the mainstay treatment for diphtheria.

Anti-Toxin

The role of anti-microbial therapy in diphtheria is to _____.

halt toxin production treat localized infection prevent transmission of the organism to contacts

Antibiotics for Diphtheria

Erythromycin | Penicillin

Antibiotics for Diphtheria: | Erythromycin Dose

40-50 mkday q6 PO/IV *max. 2 g/day

Antibiotics for Diphtheria: | Penicillin G Dose

100,000-150, 000 ukday q6 IV/IM

Antibiotics for Diphtheria: | Procaine Penicillin Dose

300,000 u/day IM - < 10 kg | 600,000 u/day IM - > 10 kg

Household contacts of diphtheria should be monitored for illness through the _____.

7-day incubation period

Prophylactic Antibiotics for Diphtheria

Benzathine Penicillin G | Erythromycin

Prophylactic Antibiotics for Diphtheria: | Benzathine Penicillin G Dose

600,000 u IM - < 6 y.o. | 1.2 M u - > 6 y.o.

Prophylactic Antibiotics for Diphtheria: | Erythromycin Dose

40-50 mkday QID PO x 10 days *max. 2 g/day

Diphtheria toxoid vaccine is given to immunized individuals who _____.

have not received a booster dose within 5 years

_____ is a facultatively anaerobic,non-spore-forming, motile, catalase (+), G (+) bacilli

Listeria monocytogenes

_____ are anaerobbic, non-sporulating, g(+) bacteria that are part of the endogenous oral flora in humans and have filamentous and branching structure.

Actinomyces

_____ are G (+) filamentous bacilli which form a beaded pattern along portions of its branching filaments.

Nocardia

_____ is a G (-), fastidious, encapsulated, oxidase (+), aerobic diplococcus occuring in kidney shaped pairs.

Neisseria meningitidis (Meningococcus)

The Meningococcus strains responsible for almost all cases of human disease are _____

A, B, C, W-135, X, Y

N. meningitidis is transmitted via _____.

aerosol droplets | respiratory secretions

Risk Factors for Meningococcal Infection

``` viral respiratory infections tobacco smoke marijuana use binge drinking night clubs/bars dormitories ```

_____ are specific bacteria adhesins which mediate the attachment of N. meningitidis to nasopharyngeal mucosal cells.

pili | opacity-associated proteins (Opa, Opc)

The most important virulence determinant of N. meningitidis is the presence of a _____ which enhances resistance to opsonophagocytic killing.

capsular polysaccharide

_____ is essential in stmulating cytokines and activating coagulation and bleeding which are hallmarks of severe meningococcal sepsis.

Endotoxin (lipopolysaccharide)

The _____ portion of the meningococcal lipopolysaccharide is responsible for the toxicity of the molecule.

Lipid A

Diffuse adrenal hemorrhage in fulminant meningococemia is called _____.

Waterhouse-Friderichsen Syndrome

Persons with inherited deficiencies of _____ are 1000x more susceptible to meningococcal infections.

properdin factor D terminal complement components

Fulminant meningococcemia progresses rapidly over several hours from fever with non-specific signs to spetic shock with prominent petechiae and purpura called _____.

purpura fulminans

Definitie diagnosis of meningococcal disease is established by _____.

isolation of N. meningitidis from a normally sterile body fluid

_____ are the drugs of choice for N. meningitidis.

β-lactam antibiotics

_____ is the most frequent neurologic sequela of meningococcal meningitis.

Deafness

Poor Prognostic Factors for Meningococcal Infections

``` hypothermia or severe hyperpyrexia hypotension purpura fulminans seizures leukopenia thrombocytopenia (DIC) acidosis ↑endotoxin and TNF-α petechiae < 12 hrs before admission absence of meningitis low or N ESR ```

Antibiotic prohylaxis for N. meningitidis is indicated for persons in contact with the patient's oral secretions _____.

7 days before onset of illness

Antibiotics for N. meningitidis Prophhylaxis

Rifampin Ceftriaxone Ciprofloxacin

N. meningitidis Prophhylaxis: | Rifampin Dose

< 1 mo. 5 mkdose PO q12 x2 days ≥ 1 mo. 10 mkdose PO q12 x 2 days *max. 600 mg PO q12

N. meningitidis Prophhylaxis: | Ceftriaxone Dose

< 15 y.o. 125 mg IM | ≥ 15 y.o. 250 mg Im

N. meningitidis Prophhylaxis: | Ciprofloxacin Dose

20 mg/kg PO * max. 500 mg PO

Meningococcal vaccination is recommended for _____.

11-21 y.o.

Antibody titers for N. meningitidis peak after _____ from vaccination.

4-6 weeks

A N. meningitidis antibody titer of _____ is considered protective.

≥ 1:4

Gonorrhea is transmitted via _____.

sexual contact | perinatal transmission

_____ is a non-motile, aerobic, non-spore forming, G (-) intracellular diplococcus with flattened adjacent surfaces.

Neisseria gonorrhoeae

Gonococcal species are differentiated from other Neiseria species by the _____.

fermentation of glucose but not maltose, sucrose or lactose

2 systems used to characterize gonococcal strains are _____.

auxotyping | serotyping

_____ is based on genetically stable requirements of strains for specific nutrients or cofactors.

Auxotyping

The most widely used Gonococcal serotyping system is based on a porin called _____.

Por1

_____ is the most common STI in sexually abused children.

Gonorrhea

N. gonorrhoeae primarily affects the _____.

columnar apithelium

Gonorrhea can cause endometritis, salpingitis and peritonitis which is collectively known as _____.

pelvic inflammatory disease (PID)

Dissemination of N. gonorrhoeae from the fallopian tubes through the peritoneum to the liver capsule results in perihepatitis called _____.

Fitz-Hugh-Curtis Syndrome

Women are more prone to disseminated gonoccocal infection during _____.

mentruation pregnancy postpartum period

The most common initial symptom of disseminated gonoccocal infection is _____.

acute polyarthralgia with fever

Clinical Syndromes of Disseminated Gonoccocal Infection

Tenosynovitis-Dermatitis Syndrome | Suppurative Arthritis Syndrome

Clinical Syndromes of Disseminated Gonoccocal Infection: | more common, fever, chills, skin lesions, polyathralgia, (+) blood CS

Tenosynovitis-Dermatitis Syndrome

``` Clinical Syndromes of Disseminated Gonoccocal Infection: monoarticular arthritis (knee), (-) blood CS ```

Suppurative Arthritis Syndrome

In _____, typical necrotic pustules on an erythematous base is distributed evenly over the extremities usually sparing the face and scalp.

disseminated gonoccocal infection

Acute endocarditis leading to rapid destruction of the _____ is an uncommon but fatal manifestation of disseminated gonoccocal infection.

aortic valve

In males, presumptive diagnosis of gonorrhea can be made by _____.

identification of G (-) intracellular diplococci in urethral discharge

All patients with gonorrhea should be tested for concomitant _____.

syphilis hepatitis B HIV C. trachomatis

_____ is recommended as the initial therapy for gonorrhea.

Ceftriaxone

For gonorrheal PID, the recommended treatment therapy is _____.

Cefoxitin + Doxycucline

Gonococcal ophthalmia neonatorium can be prevented by instilling _____ into each conjunctiva shortly after birth.

1% solution of silver nitrate | erythromycin or tetracycline ophthalmic ointment

_____ is the most common etiology of joint and bone infections in children.

Kingella kingae

_____ is a fastidious, facultative anaerobic, β-hemolytic member of the Neisseriaceae family that appears as pairs or short chains of G (-) coccobacilli with tapered ends.

Kingella kingae

_____ is a fastidious, G (-), pleomorphic coccobacillus that requires factor X (hematin) and factor V (phosphorydine nucleotide) for growth.

Haemophilus influenzae

H. influenzae requires _____. for growth.

``` factor X (hematin) factor V (phosphorydine nucleotide) ```

In the pre-vaccine era, _____ was a major cause of serious disease among children.

Hib

In Hib meningitis, _____ given shortly before or concurrent with the initiation of antimicrobial therapy decreases the risk of hearing loss.

Dexamethasone

Children with H. influenzae cellulitis have an antecedent _____ due to the seeding of organisms during bacteremia.

URTI

H. influenzae usually affects the _____.

head neck cheek preseptal region

_____ are the most common causes of otitis media.

H. influenzae S. pneumoniae Morazella catarrhalis

_____ is the drug of choice for H. influenzae.

Ampicillin

_____ is used when H. influenzae is resistant to Ampicillin.

Ceftriaxone

_____ is preferred for non-invasive H. influenzae infections.

Amoxicillin

_____ is used as antibiotic prophylaxis for H. influenzae.

Rifampin

_____ is an STD characterized by painful genital ulceration and inguinal lyphadenopathy (buboes).

Chancroid (Haemophilus ducreyi)

_____ is an unencapsulated, G (-) diplococcus and is a human specific pathogen that colonizes the respiratory tract beginning in infancy.

Moraxella catarrhalis

_____ is the sole cause of epidemic pertussis and the usual cause of sporadic pertussis.

Bordatella pertussis

_____ is a small, fastidious, G (-) coccobacilli that colonize only ciliated epithelium.

Bordatella pertussis

Pertussis is highly contagious with infection rates as high as _____.

100%

Protection against typical pertussis begins to wane _____ after vaccination.

3-5 years.

The major virulence protein of B. pertussis is the _____.

pertussis toxin

The Pertussis Toxin causes lymphocytosis by _____.

rerouting lymphocytes to remain in the circulationg blood.

Incubation period of Pertussis

3-12 days

Stages of Pertussis

Catarrhal - 1-2 weeks Paroxysmal - 2-6 weeks Convalescent - ≥ 2 weeks

Stages of Pertussis: | non-specific symptoms, congestion, rhinorrhea

Catarrhal - 1-2 weeks

Stages of Pertussis: | cough begins as a dry, intermittent, irritative hack and evolves into inexorable paroxysms

Paroxysmal - 2-6 weeks

Stages of Pertussis: | the number, severity and duration of coughing episodess diminish

Convalescent - ≥ 2 weeks

Infants _____ do not display the classic stages of pertussis.

< 3 mos.

Pertussis is characterized by cough ≥ 14 days plus _____>

paroxysms whooping post-tussive vomiting

Leukocytosis due to absolute lymphocytosis is characteristic of the _____ of pertusis.

catarrhal stage

Severe course and death from pertussis are correlated with extreme _____.

leukocytosis | thrombocytosis

_____ is the gold standard for diagnosing pertussis.

Isolation of B. pertussis in culture

The preferred culture media for B. pertussis are _____.

Regan-Lowe Charcoal Agar | Stainer-Scholte Media

_____ are the antibiotic of choice for pertussis.

Macrolides (Azithromycin)

Oral erythromycin increases the risk for _____ 7-10x in neonates.

hypertrophic pyloric stenosis

Exposure Prophylaxis for Pertussis: | < 7 y.o. with < 4 doses of pertussis vaccine

complete DTaP series

Exposure Prophylaxis for Pertussis: | < 7 y.o. with 3rd dose of pertussis vaccine 6 mos. before exposure

DTaP booster

Exposure Prophylaxis for Pertussis: | < 7 y.o. with 4th dose of pertussis vaccine 3 years before exposure

DTaP booster

Exposure Prophylaxis for Pertussis: | ≥ 9 y.o. without Tdap

Tdap

Antibiotics for Pertussis

Azithromycin Erythromycin Clarithromycin TMP-SMX

Antibiotics for Pertussis: | Azithromycin Dose

0-5 mos. - 10 mkday OD x 5 days ≥ 6 mos. - 10 mkday OD on D1, 5 mkday OD on D2-5 adults - 500 mg OD on D1, 250 mg OD on D2-5

Antibiotics for Pertussis: | Erythromycin Dose

children - 40-50 mkday QID x 14 days | adults - 2 g/day QID x 14 days

Antibiotics for Pertussis: | Clarithromycin Dose

children > 1 mo. - 15 mkday BID x 7 days | adults - 1 g/day BID x 7 days

Antibiotics for Pertussis: | TMP-SMX Dose

children > 2 mos. - TMP 8 mkday + SMX 40 mkday BID x 14 days | adults - TMP 320 mg/day + SMX 1600 mg/day BID x 14 days

_____ are motile, nonsporulating, nonencapsulated, G (-) rods that grow aerobically and are capable of facultative anaerobic growth.

Salmonellae

Sallmonella is resistant to many agents but can be killed by _____.

heating to 130°F for 1 hour or 140°F for 15 min.

Salmonella Antigens

Somatic O | Flagellar H

_____ are the most important serotypes for salmonellosis transmitted from animals to humans.

Salmonella enteritidis | Salmonella typhimurium

_____ Salmonella organisms must be ingested to cause symptomatic disease.

10^6 - 10^8

Gastric acidity inhibits multiplication of the salmonellae and most organisms are killed at _____.

gastric pH ≤ 2

Intestinal Salmonella infection results in a localized enteritis that is associated with a _____ response from the intestinal epithelium.

secretory

Intestinal Salmonella infection induces secretion of _____ and other chemoattractants from the apical surface, directing recruitment and transmigratioon of neutrophils into the gut lumen and thus preventing systemic spread.

IL-8 - basolateral surface

The most common clinical presentation of salmonellosis is _____.

acute enteritis

In Salmonella enteritis, stool typically contains _____.

PMNs | occult blood

High rates of Salmonella in Africa suggests an association with _____.

HIV

The most common sites of focal Salmonella infection are _____.

skeletal system meninges intravascular sites sites of preexisting abnormalities

_____ are not recommended for uncomplicated Salmonella gastroenteritis because suppression of normal gut flora can prolong infection and induce a chronic carrier state.

Antibiotics

S. typhimurium phage type DT104 is resistant to _____.

``` Ampicillin Chloramphenicaol Streptomycin Sulfonamides Tetracycline ```

Salmonella Gastroenteritis Treatment

Cefotaxime Ceftriaxone Ampicillin Cefixime

Salmonella Gastroenteritis Treatment: | Cefotaxime Dose

100-200 mkday q6-8 x 5-14 days

Salmonella Gastroenteritis Treatment: | Ceftriaxone Dose

75 mkday OD x 7 days

Salmonella Gastroenteritis Treatment: | Ampicillin Dose

100 mkday q6-8 x 7 days

Salmonella Gastroenteritis Treatment: | Cefixime Dose

15 mkday x 7-10 days

Typhoid Fever is caused by _____ which is G (-).

Salmonella typhi

_____ is a virulence factor present in 90% of S. typhi and has a protective effect against the host's immune system.

Polysaccharide Capsule Vi

_____ found in S. typhi interferes with phagocytosis by preventing the binding of C3 to the surface of the bacteria.

Polysaccharide Capsule Vi

Salmonella typhi is resistant to _____.

Ampicillin Chloramphenicol TMP-SMX

It takes _____ S. typhi to manifest clinical symptoms.

10^5 - 10^9

The incubation period of S. typhi is _____.

7-14 days

Primary S. typhi bacteremia results from _____.

lymphatic spread from intestinal mucosa and mesenteric LNs

Secondary S. typhi bacteremia occurs when bacteria are shed into the blood after a period of replication within the _____.

macrophages in the RES

Secondary S. typhi bacteremia coincides with _____.

onset of clinical symptoms

Typhoid Fever Pattern

stepladder rise (gradual rise)

S. typhi causes a macular or maculopapular rash called _____ may be visible around the 7-10th day of illness.

Rose Spots

Risk Factors for Typhoid Carrier Status

gallbladder disease advanced age antibiotic resistance of prevalent strains

S. typhi forms a biofilm in the _____ of a carrier.

gallbladder

The mainstay of the diagnosis of Typhoid Fever is _____.

(+) culture result

Typhoid Fever Culture Studies: | Blood

(+) early in the disease

Typhoid Fever Culture Studies | Stool

(+) after 1 week

Typhoid Fever Culture Studies\Urine

(+) after 1 week

The _____ measures antibodies against O and H antigens of S. typhi.

Widal Test

Typhoid Fever Treatment: | uncomplicated, fully sensitive

Chlorampphenicol 50-75 mkday x 14-21 days

Typhoid Fever Treatment: | uncomplicated, multidrug-resistant

Amoxicillin 75-100 mkday x 14 days Fluorouinolone 15 mkday x 5-7 days Cefixime 15-20 mkday x 7-14 days

Typhoid Fever Treatment: | uncomplicated, quinolone-resistant

Azithromycin 8-10 mkday x 7 days | Ceftriaxone 75 mkday x 10-14 days

Typhoid Fever Treatment: | uncomplicated, quinolone-resistant

Azithromycin 8-10 mkday x 7 days | Ceftriaxone 75 mkday x 10-14 days

Typhoid Fever Treatment: | severe, fully sensitive

Fluoroquinolone 15 mkday x 10-14 days

Typhoid Fever Treatment: | severe, multidrug-resistant

Fluoroquinolone 15 mkday x 10-14 days

Typhoid Fever Treatment: | severe, quinolone-resistant

Ceftriaxone 60 mkday x 10-14 days | Cefotaxime 80 mkday x 10-14 days

Individuals who excrete S. typhi for _____ after infection are considered chronic carriers

≥ 3 mos.

_____ is used to describe the syndrome of bloody diarrhea with fever, abdominal cramps, rectal pain and mucoid stools.

Dysentery

_____ causes bacillary dysentery.

Shigella

The basic virulence trait of Shigella is _____.

the ability to invade epithelial cells

_____ is a potent exotoxin in Shigella that inhibits protein synthesis.

Shiga Toxin

The Shiga Toxin is found in _____

S. dysenteria serotype 1 | Shiga Toxin-ProducingE. Coli (STEC) → HUS

The target organ of Shigella is the _____.

colon

_____ are among the most common extraintestinal manifestations of bacillary dysentery.

Neurologic findings

The most common complication if shigellosis is _____.

dehydration

_____ is a rare syndrome caused by Shigella which manifests as severe toxicity, convulsions, extreme hyperpyrexia, and headache followed by brain edema.

Ekiri Syndrome | Lethal Toxic Encephalopathy

Presumptive data supporting the diagnosis if bacillary dysentery include _____.

fecal leukocytes fecal blood leukocytosis with left shift

_____ is the recommended drug for bacillary dysentery.

Ciprofloxacin 20-30 mkday BID

_____ supplementation may be given for children with bacillary dysentery.

Vit. A 200,000 IU as single dose - lessen severity | Zinc 20 mg x 14 days - decrease duration

_____ immunization can reduce the incidence and severity of diarrheal diseases including shigellosis.

Measles

_____ is a facultatively anaerobic G (-) bacilli that usuali ferments lactose.

Escherichia coli

``` E. coli Strains: > 1 y.o. and travelers watery +++ bloody - acute colonization factor (CF) E. coli common pilus (ECP heat-labile enterotoxin (LT) heat-stable enterotoxin (ST) ```

Enterotoxigenic E. coli (ETEC)

E. coli Strains: | "Traveler's DIarrhea"

Enterotoxigenic E. coli (ETEC)

The LT in ETEC stimulates _____.

adenylate cyclase

The ST in ETEC stimulates _____.

guanylate cyclase

``` E. coli Strains: > 1 y.o. watery + bloody ++ acute invasion plasmid antigen (ipaABCD) (-) toxins ```

Enteroinvasive E. coli (EIEC)

E. coli Strains: | symptoms resemble bacillary dysentery because they share virulence genes with Shigella

Enteroinvasive E. coli (EIEC)

``` E. coli Strains: < 2 y.o. watery +++ bloody + acute, prolonged, persistent A/E lesion, intimin/Tir, EspABD, Bfp EspF, Map, EAST1, SPATEs (EspC) ```

Enteropathogenic E. coli (EPEC)

E. coli Strains: | major cause of acute and persistent diarrhea in children < 2 y.o. in developing countries

Enteropathogenic E. coli (EPEC)

E. coli Strains: | breastfeeding is protective against diarrhea

Enteropathogenic E. coli (EPEC)

E. coli Strains: | induces a characteristic attaching and effacing (A/E) histopathologic lesion

Enteropathogenic E. coli (EPEC)

``` E. coli Strains: 6 mos. - 10 y.o., elderly watery + bloody +++ acute A/E lesion, intimin/Tir, EspABD Shiga toxins (Stx1, Stx2) ```

Shiga Toxin Producing E.coli (STEC) Enterohemorrhagic E. coli (EHEC) Verotoxin Producing E. Coli (VTEC)

STEC differs from shigellosis or EIEC because _____ is uncommon.

fever

E. coli Strains: | 5-10% develop complications like HUS

Shiga Toxin Producing E.coli (STEC) Enterohemorrhagic E. coli (EHEC) Verotoxin Producing E. Coli (VTEC)

_____ are the key virulence factors for EHEC/VTEC.

Shiga toxins

``` E. coli Strains: < 2 y.o., HIV, travelers watery +++ bloody + acute, prolonged, persistent aggregative adherence fimbriae (AAF) SPATEs (Pic,Pet), ShET1, EAST1 ```

Enteroaggregative E. coli (EAEC)

E. coli Strains: associated with acute and persistent diarrhea in children < 2 y.o. in developing countries as well as chronic diarrhea in HIV (+) individuals

Enteroaggregative E. coli (EAEC)

E. coli Strains: forms a characteristic biofilm on the intestinal mucosa and induce shortening of the villi, hemorrhagic necrosis, and inflammatory responses

Enteroaggregative E. coli (EAEC)

``` E. coli Strains: > 1y.o., travelers watery ++ bloody - acute Afa/Dr, AIDA-I SPATES (Sat) ```

Diffusely Adherent E. coli (DAEC)

E. coli Strains: | produces acute watery diarrhea in children after the first 1-2 years that is not dysenteric and often prolonged

Diffusely Adherent E. coli (DAEC)

_____ is the most virulent STEC serotype and most frequently associated with HUS.

O157:H7

STEC O157:H7 is suggested by isolation of E. coli that fails to ferment _____ on _____.

sorbitol | MacConkey agar

The cornerstone of management of E. coli diarrhea is _____.

fluid and electrolyte therapy

EIEC infections can be treated with _____.

TMP-SMX

______ is a G (-) comma-shaped bacillus.

Vibrio cholerae

Vibrio cholerae is divided into serogroups by its _____.

somatic O antigen

Cholera epidemics are cause by _____.

V. cholerae O1 and O139

The most extensive cholera pandemic was caused by _____.

V. cholerae O1 El Tor

V. cholerae is transmitted through _____.

contaminated water and undercooked shellfish

Risk Factors for Severe Cholera

``` blood type O ↓gastric acidity malnutrition immunodeficiency ↓intestinal immunity ```

Large inocula of bacteria, _____ of organisms, is needed for severe cholera to occur.

> 10^8

The cholera toxin consists of _____ subunits.

5 binding B subunits | 1 active A subunit

The _____ of the cholera toxin binds to the GM1 ganglioside receptors in the intestine.

B subunit

The _____ of the cholera toxin stimulates adenylate cyclase.

A subunit

The hallmark of _____ is painless purging of profuse rice-water stools (suspended flecks of mucus) with a fishy smell.

cholera

_____ is the most severe form of cholera where purging rates of 500-1000 ml/hour occur.

Cholera Gravis

_____ is the gold standard for diagnosing cholera.

Microbiologic isolation of V. cholerae

V. cholerae can be cultured on _____.

Thiosulfate Citrate Bile Salts Sucrose (TCBS) Agar

Dark-field microscopy may be used for rapid identification of typical _____ motility in wet mounts of rice-water stools.

darting

_____ is the mainstay therapy of cholera.

Rehydration.

_____ should be used during rehydraion for cholera.

Rice-based ORS

Antiobiotics in cholera are used to _____.

shorten duration of illness decrease fecal excretion of vibrios decrease volume of diarrhea reduce the fluid requirement during rehydration

For cholera, single dose antibiotics such as _____ are recommended to increase compliance.

Doxycycline 2-4 mg/kg PO Ciprofloxacin 20 mg/kg PO Azithromycin 20 mg/kg PO

_____ are G (-), curved, thin, non-spore-forming rods that have tapered ends.

Campylobacter

Campylobacter are motile with a _____.

flagellum at 1 or both poles

_____ are microaerophilic, partially anaerobic, oxidase (+) and do not oxidize or ferment carbohydrates.

Campylobacter

Campylobacter differ from oterh enteric bacterial pathogens in that they have both _____.

N- and O-linked glycosylation capacities

_____ are a classic source of Campylobacter.

Chickens

C. jejuni has strong association with _____.

Guillain-Barre Syndrome

_____ infection should be considered when evaluating Inflammatory bowel disease.

Campylobacter

the most common presentation of Campylobacter is _____.

enteritis

Campylobacter is treated with _____ if necessary.

Erythromycin | Azithromycin

_____ is an acute demyelinating disease of the peripheral nervous system characterized by acute flaccid paralysis and is the most common cause of neuromuscular paralysis worldwide.

Guillain-Barre Syndrome

_____ is the most common Yersinia species causing human disease.

Yersinia enterocolitica

_____ causes fever, diarrhea and abdominal pain that can mimic appendicitis.

Yersinia

_____ causes acute febrile lymphadenitis seen in the bubonic plague.

Yersinia pestis

_____ is a large, G (-) coccobacillus that exhibit little or no bipolarity when stained with methylene blue and carbol fuchsin.

Yersinia enterocolitica

_____ ferments glucose and sucrose but not lactose, is an oxidase (-) facultative anaeerobe and reduces nitrate to nitrite.

Yersinia enterocolitica

Yersinia enterocolitica are motile at _____

22°C but not at 37°C

_____ are the major reservoir of Yersinia enterocolitica.

Pigs

Risk Factors for Yersinia enterocolitica Infection

iron overload hemochromatosis thalassemia sickle cell disease

Yersinia enterocolitica has been associated with _____ disease.

Kawasaki

_____ is recommended as empirical treatment for Yersinia enterocolitica.

TMP-SMX

_____ is a G (-) facultative anaerobe that is a pleomorphic non-motile, non-spore-forming coccobacillus and is a potential agent for bioterrorism.

Yersinia pestis

The most common mode of transmission of Yersinia pestis is _____

flea bite (Xenopsylla cheopis)

3 Principal Clinical Presentations of Plague

Bubonic Septicepmic Pneumonic

Clinical Presentations of Plague: | most common form

Bubonic

In the bubonic plague, lymphadenitis (buboes) develop most commonly in the _____ area.

inguinal

In the Black Death, ______ of the extremities can develop as a result of intravascular coagulation.

purpura and gangrene

Clinical Presentations of Plague: | systemic infection without buboes

Septicemic

Clinical Presentations of Plague | least common but most dangerous and lethal form

Pneumonic

______ is the drug of choice for the bubonic plague.

Steptomycin 30 mkday q12 IM x 10 days * max. 2 g/day

Postexposure prophylaxis using _____ should be given to those exposed to pneumonic plague.

Tetracycline Doxycycline TMP-SMX *7 days

_____ is a strictly aerobic, oxidase (+), G (-) rod that does not ferment lactose and may produce β-hemolysis on blood agar.

Pseudomonas aeruginosa

_____ is capable of chronic persistence due to the formation of biofilms, organized communities of bacteria encased in an extracellular matrix that protects the organism from the host immune response and the effects of antibiotics.

Pseudomonas aeruginosa

_____ infection causes ecthyma gangrenosum which begins as pink macules and progress to hemorrhagic nodules and eventually to ulcers with ecchymotic and gangrenous centers with eschar formation surrounded by an intense red areola.

Pseudomonas aeruginosa

A frequent focus preceding Pseudomonas aeruginosa bacteremia in newborns is _____.

conjunctivitis

_____ of fluid or gram of tissue is evidence suggestive of Pseudomonas aeruginosa.

≥ 100,000 CFU/ml

Antibiotics for P. aeruginosa

Ceftaziidime 150-250 mkday q6-8 IV (max. 6 g/day) Piperacillin-Tazobactam 300-450 mkday q6-8 IV (max. 12 g/day) Cefepime Ticarcillin-Clavulanate ± Gentamicin

_____ is an acute, spastic, paralytic illness (lockjaw) that is caused by the neurotoxin produced by _____.

Tetanus | Clostridium tetani

_____ is a motile, G (+), spore-forming obligate anaerobe whose spores produce a drumstick or tennis racket appearance.

Clostridium tetani

The tetanus toxin is also called _____.

tetanospasmin

_____ is the 2nd most poisonous substance known surpassed only by botulinum toxin.

Tetanospasmin

The most common form of tetanus is _____.

neonatal or umbilical

Tetanus occurs after spores germinate, multiply and produce tetanus toxin in the _____ of an infected injury site.

↓oxidation-reduction potential

Tetanus toxin binds at the _____.

neuromuscular junction

Tetanus toxin initiallly enters the _____ by endocytosis.

motor nerve

In the sciatic nerve, tetanus transport rate was found to be _____.

3.4 mm/hr

The tetanus toxin exits the motor neuron in the spinal cord and enters the adjacent spinal inhibitor interneurons where it prevents release of _____.

glycine | GABA

The incubation period of C. tetani is _____.

2-14 days

The presenting symptom of 50% of tentanus cases is _____.

trismus

_____ results from intractable spasms of facial and buccal muscles.

Risus Sardoniucus (sardonic smile)

When paralysis from tetanus extends to the abdominal, lumbar, hip and thigh muscles, the patient may assume a hyperextension of the body called _____.

opisthotonos

Fever is common in tetanus because of _____.

the menergy consumed by spastic muscles

Neonatal tetanus manifests within _____.

3-12 days from birth

_____ results in painful spasms of the muscles adjacent o the wound site.

Localized Tetanus

Tetanus toxin cannot be inhibited by TIG after it hasbegun its _____.

axonal ascent to the spinal cord

_____ is the antibiotic of choice for tetanus.

Penicillin G

The treatment of generalized tetanus requites _____.

muscle relaxants | neuromuscular blockade

Favorable Prognosis for Tetanus

long incubation period absence of fever localized disease

Poor Prognosis for Tetanus

trismus < 7 days after injury | generalized tetanic spasms < 3 days after trismus

Diphtheria Toxoid-Tetans Toxoid-Acellular Pertussis (DTaP) should be given at _____.

2-4-6 mos.

Diphtheria Toxoid-Tetans Toxoid-Acellular Pertussis (DTaP) booster should be given at _____.

4-6 y.o. | 10 year intervals thereafter

Maternal immunization of at least _____ is recommended to eliminate neonatal tetanus.

2 doses of tetanus toxoid

Tetanus Prophylaxis: | clean, minor wound, uncertain or < 3 doses of tetanus toxoid

Tdap

Tetanus Prophylaxis: | clean, minor wound, ≥ 3 doses of tetanus toxoid

none

Tetanus Prophylaxis: | major wound, uncertain or < 3 doses of tetanus toxoid

Tdap and TIG

Tetanus Prophylaxis: | major wound, ≥ 3 doses of tetanus toxoid

none

A tetanus toxoid booster is given to those who completed primary immunization when _____.

clean, minor wound, ≥ 10 years since last booster | serious wound, ≥ 5 years since last booster

_____ are non-spore-forming, non-motile, pleiomorphic, obligately aerobic, weakly G (+) bacilli.

Mycobacterium tuberculosis

_____ grow in synthetic media containing glycerol as the carbon source and ammonium salts as the nitrogen source (Lowenstein-Jensen).

Mycobacterium tuberculosis

_____ is the hallmark of TB.

Acid Fastness * the capacity to form stable mycolate complexes with arylmethane dyes and resist decoloration with ethanol and ydrochloric acids

A reactive TST without clinical or radiographic manifestations is the hallmark of _____

latent TB

The primary complex (Ghon complex) of TB includes _____.

local parenchymal infecction | lymphadenopathy

Bacterial replication of TB is more likely to occur in the _____.

lung apices brain kidneys bones

The most common result of female genital tract TB is _____.

infertility

A TST _____ is positive for any age.

≥ 10 mm

The hallmark of PTB is _____.

large lymphadenitis | small lung focus

Sequence of PTB

hilar lymphadenopathy → focal hyperinflation → atelectasis → collapse-consolidation (segmental tuberculosis)

Calcification in TB lesions implies that an infection has been there for _____.

6-12 mos.

Most Common Symptoms of TB

non-productive cough | mild dyspnea

Reactivation TB is more common in those who acquire the infection at _____.

> 7 y.o.

The most common CXR findings in reactivation TB are _____ in the upper lobes.

extensive infiltrates | thick-walled cavities

Pleural Fluid Findings in TB

``` yellow SG 1.012-1.025 protein 2-4 g/L ↓glucose ↑WBCs (lymphocytic) ```

The most common cause of cardiac TB is _____.

pericarditis

The most clinically significant form of disseminated TB is _____.

miliary TB

_____ is the most common extrapulmonary TB in children.

Scrofula

The _____ is often the site of greatest involvement in CNS TB.

brainstem (CN III, VI, VII)

Stages of TB: | non-specific symptoms, no focal neurologic signs

Stage 1

Stages of TB: | lethargy, nuchal rigidity, seizures, (+) Kernig and Brudzinski signs, hypotonia, vomiting, CN palsies

Stage 2

Stages of TB: | coma, hemiplegia, paraplegia, hypertension, decerebrate posturing, deterioration of vital signs, death

Stage 3

CSF findings in TB

↑WBC 10-500 cell/mm3 (lymphocytic) ↓glucose < 40 mg/dl ↑protein 400-5000 mg/dl

CT Scan MRI FIndings in TB

basilar enhancement communicating HCP focal ischemia (arteritis)

Tuberculomas in children are often found in the _____.

infratentorial area

The classic manifestation of tuberculous spondylitis is progression to _____.

Pott's Disease

TB enteritis usually involves the _____.

jejunum ileum near Peyer patches appendix

Anti-TB Drugs: | optic neuritis, decreased red-green discrimination, GI disturbances, hypersensitivity

Ethambutol

Anti-TB Drugs: | mild hepatic enzyme elevation, hepatitis, peripheral neuritis, hypersensitivity

Isoniazid

Anti-TB Drugs: | hepatotoxic effects, hyperuricemia, arthralgias, GI tract upset.

Pyrazinamide

Anti-TB Drugs: orange discoloration of body fluids, vomiting, hepatitis, flu-like symptoms, thrombocytopenia, pruritus, ineffectve oral contraceptives

Rifampicin

TB osteomyelitis, arthritis, meningitis and disseminated TB should be treated for _____.

9-12 mos.

Corticosteroids are used for _____ TB.

meningitis endobronchial pericardial effusion miliary

_____ should be given to partients with latent TB.

Isoniazid x 9 mos.

_____ have been associated with the ability of virulent TB strains to produce disease.

``` trehalose dimycolate (cord factor) sulfatides ```

_____ is responsible for the morphologic appearance of serpentine cords of TB bacilli in cllose, parallel arrangements.

Cord Factor

_____ are peripherally located glycolipids that inhibit fusion of secondary lysosomes with bacilli-containing phagosomes within a macrophage, promoting intracellular survival of TB

Sulfatides

The gold standard for diagnosing TB is _____.

TB Culture

_____ is a long, motile spirochete with finely tapered ends.

Treponema pallidum

Treponema pallidum Subspecies: | venereal syphilis

pallidum

Treponema pallidum Subspecies: | yaws

pertenue

Treponema pallidum Subspecies: | bejel, endemic syphilis

endemecium

Treponema pallidum Subspecies: | pinta

carateum

Detection of T. pallidum requires _____.

dark-field microscopy phase contrast microscopy direct immunofluorescence staining

Acquired Syphilis is transmitted through _____.

vaginal, anal and oral exposure

Primary syphilis is characterized by _____.

chancre | regional lymphadenitis

In syphilis, a painless papule appears at the site of entry _____ after inoculation and develops into a clean, painless, highly contagious ulcer (chancre).

2-6 weeks

Untreated patients develop secondary syphilis _____ after the chancre heals.

2-10 weeks

Manifestations of secondary syphilis include generalized non-pruritic maculopapular rash involving th _____.

pals and soles.

_____ are gray-white erythematous wart-like plaques which occur in moist areas around the anus and vagina of those infected wih syphilis.

Condyloma lata

Syphilis meningitis is characterized by _____.

CSf pleocytosis | elevaated protein

Secondary syphilis infection becomeas latent withiin _____.

1-2 mos. after onset of rash

_____ is marked by neurologic, cardiovascular and gummatous lesions.

Tertiary Syphilis

_____ are non-suppurative granulomas of the skin and muskuloskeletal system resulting from the host's hypersensitivity reaction to syphilis.

Gummas

All cstages of congenital syphilis are characterized by _____.

vasculitis with progression to necrosis and fibrosis

_____ anemia is characteristic of syphilis.

Coomb's negaive hemolytic anemia

_____ causes osteochondritis, periostitis and a mucocutaneous rash manifesting with erythematous macules followed by desquamation involving hands and feet.

Syphilis

Mucus patches, persistent rhinitis (snuffles) and condylomatous lesions are highly characteristis fetues of mucus membrane involvement in _____.

syphilis

X-rays showing Wimberger lines, osteochondritis aand periostitis of the long bones are suggestive of _____.

syphilis

Manifestations of Syphilis: | metaphyseal demineralization of the medial aspect of the proximal tibia

Wimberger lines

Manifestations of Syphilis: | bony prominence of the forehead due to persistent or recurrent periostitis

Olympian brow

Manifestations of Syphilis: | painful osteochondritis resulting in irritability and refusal o move the involved extemity

pseudoparalysis of Parrot

Manifestations of Syphilis: | thickening of the sternoclavicular third of the clavicle

Higoumenakia sign

Manifestations of Syphilis: | anterior bowing of the midportion of the tibia

Saber shins

Manifestations of Syphilis: peg-shaped upper central incisors, erupt during the 6th year of life with abnormal enamel, notched along the biting surface

Hutchinson teeth

Manifestations of Syphilis: | abnormal 1st lower molars (6 y.o.) characterized by small biting surface and excessive number of cusps

Mulberry molars

Manifestations of Syphilis: | depression of the nasal root resulting from destruction of the adjacent bone and cartilage

Saddle nose

Manifestations of Syphilis: | linear scars that extend in a spoke-like pattern from previous mucocutaneous fissures of the mouth, anus and genitalia

Rhagades

Manifestations of Syphilis: latent meningovascular infection, occurs in adolescence, behavioral changes, focal seizures, loss of intellectual function

Juvenile paresis

Manifestations of Syphilis: | rare spinal cord involvement and cardiovascular involvement with aortitis

Juvenile tabes

Manifestations of Syphilis: | Hutchinson teeth, interstitial keratitis, CN VIII deafness

Hutchinson triad

Manifestations of Syphilis: painless joint swelling (knees) due to synovitis with sterile synovial fluid, spontaneous remission occurs after several weeks

Clutton joint

Manifestations of Syphilis: manifests with intense photophobia and lacrimation, followed within weeks or months by corneal opacification and complete blindness

Interstitial keratitis

Manifestations of Syphilis: | appears at any age, manifests initially as vertogo and high-tone hearing loss, progresses to permanent deafness

CN VIII deafness

_____ are sensitive nontreponemal tests that detect antibodies against phospholipid antigen on the treponeme surface that crossreact with mammalian cardio-lipid-lecithin-cholesterol antigens

VDRL, RPR

_____ is the drug of choice for syphilis.

Penicillin

_____ is the drug of choice for congenital syphilis.

Penicillin G 200,000-300,000 ukday IV q4-6 x 10 days

_____ is the drug of choice for primary, secondary and early latent syphilis.

Penicillin G 50,000 u/kg IM as single dose *max. 2.4 M u

_____ is the drug of choice for late latent syphilis or syphilis of unknown duration.

Penicillin G 50,000 u/kg IM x 3 doses 1 week apart *max. 2.4 M u

_____ is the drug of choice for neurosyphilis.

Penicillin G 200,000-300,000 ukday IV q4-6 x 10 days

Persons exposed within _____ of diagnosis of syphilis in a sex partner should be treated.

≤ 90 days

Persons exposed within _____ of diagnosis of syphilis in a sex partner should be treated.

≤ 90 days

_____ are aerobic motile spiral bacteria with a terminal hook at 1 or both ends.

Leptospora

_____ are the principal source of Leptospira.

Rats

Leptospirosis follows a _____ course.

biphasic Initial/Septicemic Immune/Leptospiruric

The initial or septicemic phase of leptospirosis lasts _____ during which leptospires can be isolated from the _____.

2-7 days | blood, CSF, other tissue

Abrupt onset of flu-like illness including severe debilitating myalgia most prominent in the lower extemities, lumbosacral spine and abdomen occurs during the _____.

Initial/Septicemic Phase of Leptospirosis

Conjunctival suffusion with photophobia and orbital pain, generalized lymphadenopathy and hepatosplenomegaly occur during the _____.

Initial/Septicemic Phase of Leptospirosis

Appearance of circulating antibody, disappearance of organisms from the blood and CSF, recurrence of fever, aseptic meningitis and localization of leptospires in the tissues occur during the _____.

Immune/Leptospiruric Phhase of Leptospirosis

_____ is severe Leptospirosis characterized by jaundice, renal failure, thrombocytopenia, hemorrhage and cardiovascular collapse.drug of choice for leptospirosis is _____.

Weil SyndromePenicillin G 60-8 M u/m2/day q4

The principal cause of death in Weil Syndrome is _____.

acute renal failure

Use of Warthin-Starry silver staining, PCR, IF and immunohistochemical methods permits diagnosis of _____.

Leptospirosis

The gold standard diagnostic method for leptospirosis is _____.

microscopic agglutination test (LeptoMAT)

Leptospires can be isolated from the blood or CSF during the _____ of illness.

first 10 days

Leptospires can be isolated from the urine during the _____ of illness.

2nd week

The drug of choice for leptospirosis is _____.

Penicillin G 6-8 M u/m2/day q4 IV x 7 days

_____ is used for leptospirosis patients who are allergic to Penicillin.

Doxycycline 2 mkday BID *max. 100mg

_____ is used as prophylaxis for leptospirosis.

Doxycycline 200 mg PO

_____ is an obligate intracellular pathogen which has a G (-) envelope without a detectable peptidoglycan.

Chlamydia pneumoniae

Chlamydiae are characterized by a unique developmental cycle with morpholigically distinct infectious and reproductive bodies namely _____

``` Elementary Body (EB) - infectious Reticulate Body (RB) - reproductive ```

Chlamydial _____ attach to the host cell by a process of electrostatic binding and taken by endocytosis.

elementary bodies

Chlamydial _____ undergo binary fission then differentiate into elementary bodies after 36 hours which are released by cytolysis or exocytosis.

reticulate bodies

_____ usually occurs as a classic atypical (non-bacterial) pneumonia characterized by mild constitutional symptoms.

Chlamydial pneumonia

CXR findings which appear worse than the patient's clinical status is characteristic of _____.

Chlamydial pneumonia

Diagnosis of C. pneumoniae is based on _____

posterior nasopharyx tissue culture

Acute chlamydial infection using the microimmunofluorescence (MIF) test is defined by a _____.

↑4x in IgG titer | ≥ 16 IgM titer

Antibiotic therapy for chlamydial pneumonia lasts for _____.

≥ 2 weeks

Treatment for Chlamydia pneumoniae

Erythromycin 40 mkday PO BID x 10 days Clarithromycin 15 mkday PO BID x 10 days Azithromycin 10 mkday PO on D1 then 5 mkday PO on D2-5

_____ is the most important preventable cause of blindness worldwide.

Trachoma

_____ begins as a follicular conjunctivitis which heals leading to conjunctival scarring that result in entropion causing corneal ulceration, scarring and blindness.

Trachoma

Criteria for Trachoma

conjunctival scarring vascular pannus limbal follicles lymphoid vesicles on the upper tarsal conjunctivae *at least 2

_____ is given as treatment for trachoma.

Azithromycin 20mg/kg as single dose *max. 1g

_____ is a major cause of epididymitis and non-gonococcal urethritis.

Chlamydia trachomatis

Around 50% of men with gonorrhea are co-infected with _____.

Chlamydia trachomatis

Perinatally acquired Chlamydia trachomatis can persist for _____.

≥ 3 years

Definitive diagnosis of genital chlamydial infection is accomplished by _____.

tissue culture | inclusions in fluorescent antibody staining

Culture specimens for genital chlamydia should be taken from _____.

males - urethra | females - endocervix

Chlamydia trachomatis is treated with _____.

Azithromycin 1 g PO as single dose | Doxycycline 100 mg PO BID x 7 days

Sex partners of chlamydia patients should be treated if the last sexual contact was within _____ from onset of symptoms.

60 days

30-50% if infants born to mothers with active, untreated chlamydial infections develop _____.

conjunctivitis

_____ occurs at 1-3 mos. presenting as persistent cough, tachypnea, (-) fever, rales, (-) wheezing, eosinophilia (> 400 cells/mm3).

C. trachomatis pneumonia

The most consistent CXR finding in C. trachomatis pneumonia is _____,

hyperinflation | minimal interstitial or alveolar infiltrates

The recommended treatment for C. trachomatis conjunctivitis or pneumonia is _____.

Erythromycin 50 mkday QID PO x 14 days | Azithromycin 20 mkday OD PO x 3 days

Pregnant women with C. trachomatis should be treated with _____.

Azithromycin 1 g PO as single dose | Amoxicillin 500 mg PO TID x 7 days

_____ is a systemic STD caused by the L1, L2 and L3 serotype of the LGV biovar of C. trachomatis.

Lymphogranuloma Venereum

LGV strains of C. trachomatis have a predilection for _____.

lynphoid tissue

LGV Stages: | painless transient papule in the genitals

1st stage

LGV Stages: | unilateral, femoral or inguinal lymphadenitis with enlarging painful buboes

2nd stage

LGV Stages: | genitoanorectal syndrome with rectovaginal fistulas, rectal strictures and urethral destruction

3rd stage

The recommended treatment for LGV is _____.

Doxycycline 100 mg PO ID x 21 days

Invasive candidiasis is a leading cause of mortality in _____.

hospitalized immunocompromised patients

Morphologic Forms of Candida

blastospores or yeast cells chlamydospores pseudomucelium

Morphologic Forms of Candida: | ocal to round, 3-6 mm

blastospores or yeast cells

Morphologic Forms of Candida: | double-walled, 7-17 mm, at the terminal end of a pseudohypha

chlamydospores

Morphologic Forms of Candida: | a mass of pseudohyphae, tissue phase

pseudomycelium

Morphologic Forms of Candida: | Among Candida species, _____ accounts for most human infectiona.

Candida albicans

_____ forms a germ tube when suspended in rabbit or human serum and incubated for 1-2 hours.

C. albicans

Amphotericin B deoxycholate is inactive against 20% of strains of _____.

C. lusitaniae

Fluconazole is inactive against all strains of _____ and 5-25% of strains of _____.

C. krusei | C. glabrata

Candida is a common cause of _____ in newborn infants.

oral thrush | diaper dermatitis

_____ is the 3rd mostc ommon cause of sepsis in preterms.

Candida

Risk Factors for Candidiasis

``` prematurity low birthweight broad-spectrum antibiotics abdominal surgery central line ```

_____ is the treatment of choice for congenital cutaneous candidiasis in full-term infants.

Topical Antifungal Therapy

_____ is the treatment of choice for congenital cutaneous candidiasis in full-term infants.

Systemic Antifungal Therapy

Systemic antifungal therapy should be admnistered for _____ from the last (+) Candida culture.

21 days

_____ is the mainstay treatment fot systemic candidiasis and is active against both yeast and mycelial forms.

Amphoteriicin B deoxycholate

_____ is a superficial mucous membrame infection caused by candida.

Oral Thrush

_____ is the drug of choice for oral thrush.

Nystatin

_____ is the drug of choice for recalcitrant of recurrent oral thrush.

Fluconazole as single dose

_____ is the most common infection caused by Candida and is characterized by a confluent erythematous rash with satellite pustules.

Siaper Dermatitis.

Diaper rash should be treated when it has been present for _____.

> 3 days

The topical antifungal drugs of choice for diaper dermatitis are _____.

nystatin clotrimazole miconazole

Candida paronychia may be treated with _____.

topical antifungals

Ungual Candida infections may require _____.

systemic azoles

_____ is a common Candida infection of pubertal and postpubertal females.

Vulvovaginitis

Candida vulvovaginitis may be treated with _____.

vaginal creams nystatin clotrimazole miconazole

_____ is the most common cause of invasive candidiasis in immunocompromised patients.

C. albicans

_____ are the most common Candida infections in HIV (+) patients.

oral thrush | diaper dermatitis

Oral Candidiasis in HIV: | fiery erythema of the mucosa or loss of papillae of the tongue

atrophic candidiasis

Oral Candidiasis in HIV: | oral symmetric white plaques

chronic hyperplastic candidiasis

Oral Candidiasis in HIV: | erythema and fissuring of the angles of the mouth

angular chelitis

_____ is usually necessary for oral candidiasis in HIV (+) patients.

systemic fluconazole or itraconazole

_____ decreases the incidence of candidemia in bone marrow transplant recipients.

Fluconazole prophylaxis

_____ is a group of heterogenous immune disorders with a primary defect of T-lymphocyte responsiveness to Candida.

Chronic Mucocutaneous Candidiasis

_____ risk factors associated with chronic mucocutaneous candidiasis.

``` hypoparathyroidism Addison disease hyperimmunoglobulin E syndrome (Job syndrome) HIV inhaled corticosteroids ```

_____ are necessary to treat chronic mucocutaneous candidiasis.

topical antifungal therapy | systemic azoles

_____ is an invasive fungal disease caused by a monomorphic, encapsulated yeast.

Cryptococcosis

_____ is the most common etiologic agent causing cryptococcosis and is the predominant pathogenic fungal infection among persons with HIV.

Cryptococcus neoformans

C. neoformans is acquired by _____.

inhalation of fungal spores (5-10 um) which are engulfed by alveolar macrophages

_____ is the 3rd most common invasive fungal infection after candidiasis and aspergillosis in organ transplant patients.

Cryptococcosis

_____ is the most important host defense for producing granulomatous inflammation and thus containing cryptococcal infection.

Cell-Mediated Immunity

_____ is the most common form of cryptococcosis.

Pneumonia

_____ is the most common predisposing factor for disseminated cryptococcosis.

Advanced HIV Infection

_____ is the most common clinical manifestation of disseminated cryptococcal infection.

Meningitis (subacute or chronic)

The definitive diagnosis of cryptococcosis is made by _____.

culture | histology

_____ is the most useful diagnostic test for cryptococcosis.

Latex Agglutination Test

Immunocompetent patients with asymptomatic or mild cryptococcal pneumonia may be observed or given _____.

Fluconazole - 6-12 mkday (max. 200-400 mg/day) Itraconazole - 5-10 mkday q12 (max. 200-400 mg/day *for 3-12 mos.

Patients with cryptococcemia, severe cryptococcosis, with antigen titers of > 1:8 should be treated in a staged approach using _____.

Induction - Amphotericin B + Flucytosine (min. 2 weeks) Consolidation - oral Fluconazole or Itraconazole (6-12 mos.) Maintenance

Anti-Fungal Dose: | Amphotericin B deoxycholate

1 mkday

Anti-Fungal Dose: | Amphotericin B lipid complex

5 mkday

Anti-Fungal Dose: | Liposomal Amphoericin B

5 mkday

Anti-Fungal Dose: | Amphotericin B colloidal dispersion

5 mkday

Anti-Fungal Dose: | Fluconazole

12 mkday

Anti-Fungal Dose: | Voriconazole

8 mkdose q12

Anti-Fungal Dose: | Micafungin

2-4 mkday

Anti-Fungal Dose: | Capsofungin

50 mg/m2/day

Anti-Fungal Dose: | Anidulafungin

1.5 mkday

_____ is a single-stranded, lipid-enveloped RNA virus in the family Paramyxoviridae and genus Morbillivirus

Measles

Of the 6 major structural proteins of measles, the 2 most important in terms of induction of immunity are _____

hemaglutinin (H) protein | fusion (F) protein

Measles is transmitted through _____.

contact with large droplets or small-droplet aerosols

Measles patients are infectious from _____.

3 days before up to 4-6 days after onset of rash.

The histology of _____ rash and exanthem reveals intracellular edema and dyskeratosis associated with formation of epidermal syncytial giant cells with up to 26 nuclei.

measles

In lyphoreticular tissue of measles patients, _____ is prominent.

lyphoid hyperplasia

Fusion of infected cells results in multinucleated giant cells, _____ that are pathognomonic for measles, with up to 100 nuclei and intracytoplasmic and intranuclear inclusions.

Warthin-Finkeldey giant cells

Phases of Measles

incubation period prodromal illness exanthematous phase recovery

In primary measles viremia, the virus is disseminated to the _____.

reticuloendothelial system

In secondary measles viremia, the virus is spread to the _____.

body surfaces

_____ are enanthem which are pathognomonic for measles.

Koplik Spots

Koplik spots appear _____ before onset of rash.

1-4 days

A measles rash appears after _____ as _____ starting at the _____.

3-5 days from onset of symptoms erythematous macules facespreading to the trunk and extremities

The symptoms of measles intensify for_____ until the 1st day of the rash.

2-4 days

With the onset of _____, measles symptoms begin to subside.

rash

The measles rash fades over _____ in the same progression it appeared, leaving behind a _____.

7 days, fine desquamation

Of the major symptoms of measles, _____ lasts the longest, often up to 10 days.

cough

Children who had received the original formalin-inactiated measles vaccine at times demostrate a more severe form called _____.

atypical measles

Measles is serologically confirmed by the identification of _____ in the serum.

Measles IgM

Measles IgM appears _____ and remains detectable for about _____.

1-2 days after onset of rash | 1 mo.

There is _____ rise in measles IgG in acute and convalescent specimens collected 2-4 weeks later.

4x rise

Morbidity and mortality from measles are greatest in patients _____.

< 5 y.o. | > 20 y.o.

_____ is the most common cause of death from measles.

Pneumonia

The most common pathogens causing secondary pneumonia in measles are _____.

S. pneumoniae H. influenzae S. aureus

Following severe measles pneumonia, the final common pathway to a fatal outcome is often the development of _____.

bronchilotis obliterans

_____ is the most common complication of measles.

Otitis Media

A severe form of measles manifesting with hemorrhagic skin eruption and causing death was called _____.

hemorrhagic measles | "black measles"

Indications for Vit. A in Measles

6 mos.- 2 y.o. hospitalized patients with complications immunodeficiency vitamin A deficiency impaired intestinal absorption moderate-severe malnutrition immigration from areas with high measles mortality

Vit. A Dose for Measles

< 6 mos. - 50,000 IU 6 mos.-1 y.o. - 100,000 IU ≥ 1 y.o. - 200,000 IU

Patients shed measles virus from _____ to _____.

7 days after exposure | 4-6 days after onset of rash

The measles vaccine is effective in preventio or modification of measles if given within _____ of exposure.

72 hours

The measles immunoglobulin may be given up to _____ after exposure.

6 days

Measles immunoglobulin is recomnded for _____.

household contacts infants < 6 mos. pregnant wommen immunocompromised patients

_____ is a chronic complication of measles with a delayed onset and an outcome that is nearly always fatal.

Subacute Sclerosing Panencephalitis (SSPE)

The clinical manifestations of SSPE begin _____ after primary measles infection.

7-13 years

The hallmark of the 2nd stage of SSPE in _____ which coincides with the involvement of the deeper structures of the brain including the basal ganglia.

massive myoclonus

In the 3rd stage of SSPE, involuntary movements disappear and are replaced by _____ that result from the destruction of deeper centers in the basal ganglia

choreoathetosis immobility dystonia lead pipe rigidity

The 4th stage of SSPE is characterized by the loss of critical centers that support _____.

breathing, HR, BP

CSF Findings in SSPE

elevated IgG and IgM titers (> 1:8)

EEG Findings in SSPE

suppression-burst pattern in myoclonic phase

SSPE patients die within _____ of onset from infection.

1-3 years

_____ is also known as German Measles or 3-day Measles.

rubella

_____ is a member of the family Togaviridae and the only species of genus Rubivirus.

Rubella

_____ is a single-stranded RNA virus wih a lipid envelope and 3 structural proteins.

Rubella

Followinig rubella infection, the virus replicates in the _____ then spreads to the _____.

respiratory epithelium | regional lymph nodes

Rubella viremia is most intense at _____ after infectio.

10-17 days

Viral shedding of rubella from the nasopharynx begins _____ and may be detected up to _____.

10 days after infection | 2 weeks after onset of rash

The period of highest communicability of rubella is _____ the appearance of the rash.

5 days before to 6 days after

Maternal rubella infection during the _____ results in the most severe and widespread defects.

first 8 weeks of gestation

The most distinct features of congenital rubella is _____.

chronicity

The incubation period of rubella is _____.

14-21 days

The prodrome of rubella presents as _____.

``` low-grade fever sore throat red eyes eye pain headache malaise anorexia lymphadenopathy ```

The first manifestation of rubella in children is _____.

rash

_____ may cause tiny, rose-colored lesions in the oropharynx called Forchheimer spots.

Rubella

Rubella rash lasts for _____.

3 days

The most common test for Rubella is _____,

IgM enzyme immunosorbent assay

_____ is the most serious complication of postnatal rubella.

Encephalitis

_____ is a rare complication of rubella thaat is similar to SSPE.

Progressive Rubella Panencephalitis (PRP)

_____ is the single most common finding among infants with congenital rubella.

Nerve Deafness

Retinal Findings in Rubella

salt and pepper retinopathy

_____ are the most common eye finding in rubella.

Cataracts

Late Onset Symptoms of Congenital Rubella

``` diabetes mellitus (20%) thyroid dysfunction (5%) galucoma ```

treatment for rubella is _____.

supportive

_____ is of special importance to congenital rubella syndrome because early intervention may improve outcomes.

Hearing Screening

Patients with rubella must be isolated for _____.

7 days

_____ is characterized by fever, bilateral or unilateral parotid swelling and tenderness and the frequent occurrence of meningoencephalitis and orchitis.

Mumps

_____ is in the family Paramyxoviridae and the genus Rubulavirus.

Mumps

_____ is a single stranded pleomorphic RNA virus encapsulated in a lipoprotein envelope and possessing 7 astructural proteins.

Mumps

Mumps Surface Glycoproteins

hemagglutitnin-neuraminidase (HN) | fusion (F)

Mumps Surface Glycoproteins: | absorption of the virus into the host cells

hemagglutitnin-neuraminidase (HN)

Mumps Surface Glycoproteins: | penetration into cells

fusion (F)

The mumps virus appears in the saliva from _____.

7 days before to 7 days after parotid swelling appears

The period of maximum infectiousness of mumps is _____.

1-2 days before to 5 days after onset of paotid swelling

The incubation period of mumps is _____.

12-25 days (usually 16-18 days)

Mumps presents with a prodrome lasting _____ presenting as _____.

1-2 days | fever, headache, vomiting, achiness

The parotid swelling in mumps peaks at _____ and subsides at _____.

3 days, 7 days

The mumps virus can be isolated from _____.

upper airway secretions CSF urine

Confirmation of the presence of parotitis is demonstrated by increased _____ levels.

amylase

_____ is usually caused by S. aureus and is unilateral, extemely tender, associated with inc. WBC and may have purulent drainage from the Stensen duct.

Purulent Parotitis

The most common complications of mumps are _____.

meningitis | gonadal involvement

Maternal infection with mumps results in _____.

fetal wastage

The mumps virus enters the CNS through the _____.

choroid plexus

_____ has been found in 40-60% of patients with mumps parotitis.

CSF pleocytosis

In males, _____ is 2nd only to parotitis as a common finding in mumps.

orchitis

Pancreatitis may occur in mumps with or without _____.

parotitis

Mumps Immunization Schedule and DOse

MMR x 2 doses 1st dose - 12-15 mos. 2nd dose - 4-6 y.o.

Presumptive Evidence of mumps Immunity

1. documentation of adequate vacccination 2. labortory evidence 3. birth before 1957 4. documentation of diagnosed mumps

_____ are non-enveloped, singele-stranded, positive-sense viruses in the Picornaviridae family .

Enteroviruses

_____ are the only known reservoir for enteroviruses.

humans

The incubatiojn period for enteroviruses in _____.

3-6 days

The incubation period for acute hemorrhagic conjunctivitis is _____.

3 days

Development of _____ is the most important immune defense against enteroviruses.

type-specific antibodies

_____ are the most common sypmtomatic manifestations of enteroviruses.

Non-Specific Febrile illnesses

Hand-foot-and-mouth disease is caused by _____.

coxsackievirus A16

_____ is characterized by sudden onset fever, sore throat, dysphagia and lesions in the posterioir pharynx.

Herpangina

_____ is characterized by paroxysmal thoracic pain due to myositis involving the chest and abdominal wall muscles.

Pleurodynia (Bornholm Disease)

Pleurodynia is caused by _____.

coxsackievirus 1, 3, 5 | enterovirus 1, 6

Acute hemorrhagic conjunctivitis is caused by _____.

coxsackie A24/A24 | enterovirus 70

Acute hemorrhagic conjunctivitis is spread through _____.

eye-hand-fomit-eye transmission

Enteroviruses account for 25-35% of _____.

myocardiitis | pericarditis

_____ are 2nd only to mumps as causes of orchitis.

Coxsackie B viruses

_____ are the most common cause of viral meningitis in mumps-immunized populations.

Enteroviruses

_____ is the gold standard for confirming enterovirus infection.

Viral Culture (cell line combinations)

_____ is the mainstay therapy for enteroviruses.

Supportive Therapy

_____ is cused by the human parvovirus B19, a single-stranded DNA virus.

Erythema Infectiosum (5th Disease)

The affinity of parvovirus to red blood celll progenitor cells makes it an important cause of _____.

aplastic crisis

Maternal parvovirus infection causes _____.

fetal anemia | hydrops fetalis

The cell receptor for parvovirus B19 is the _____ which is a glycolipid present on erythroid cells.

erythrocyte P antigen

Parvovirus replicates in actively dividing erythroid cells ealding to cell death that results in _____.

erythroid aplasia | anemia

Parvovirus B19 is transmitted by _____.

respiratory secretions | blood transfusions

The incubation period of parvovirus B19 is _____.

4-14 days

The characteristic rash of erythema infectiosum is the _____ which is seen with _____

"slapped cheek" rash | circumoral pallor

Erythema infectiosusm causes an erythematous symmetric, maculopapular, truncal rsh which appears _____ later but fades into a _____.

1-4 days | lacy reticulated rash (2-40 days)

The reticulocyte count in a patient in aplastic crisis from parvovirus is _____.

low or 0 (7010 days)

_____ may be used in immunodeficient patients with severe anemia caused by parvovirus.

IVIg

Maternal parvovirus infection causes _____.

fetal heart failure, hydrops fetalis, fetal death

Maternal parvovirus infection causes _____.

fetal heart failure hydrops fetalis fetal death

Parvovirus B19 causes a syndrome with fever, pruritus and edema and erythema localized to the distal extremities called _____.

papular purpuric "gloves and socks" syndrome (PPGSS)

_____ occurs in individuals previously infected with 1 type of HSV and has been infected by another.

on-primary 1st Infection

HSV establishes latent infection in _____.

regional sensory ganglion neurons

_____ contains a double-stranded DNA genome of 152 kb that encodes 84 proteins.

Herpes Simplex Virus (HSV)

The _____ DNA is contained in an icosadeltahedral capsid which is surrounded by an outer envelope composed of a lipid bilayer containing at least 12 glycoproteins.

HSV

HSV glycoproteins are major targets for _____.

humoral immunity

Non-structural proteins of HSV are targeted by _____.

cellular immunity

_____ are encoded proteins in HSV which are targets for antiviral drugs.

viral DNA polymerase | thymidine kinase

HSV-1 has a greater propensity to cause _____.

oral infections

HSV-2 has a greater propensity to cause _____.

genital infecitions

_____ is a leading cause of sporadic, fatal viral encephalitis.

HSV

The hallmarks of HSV infections are _____.

skin vesicles | shallow ulcers

_____ infections manifest as 2-4 mm vesicles that are surrounded by an erythematous base.

HSV

Herpes gingivostomatitis in children _____.

6 mos.-5 y.o.

Herpes gingivostomatitis resolves in _____.

7-14 days

_____ are the most common manifestation of recurrent HSV-1 infection.

fever blisters or cold sores

The most common site for herpes labialis is the _____.

vermillion border of the lip

Cutaneous HSV infections usually occur in contact sports such as _____.

wrestling (herpes gladiatorum) | rugby (scrum pox)

_____ is HSV infection of the fingers and toes.

Herpes Whitlow

_____ presents as local burning and tenderness followed by vesicles on the genital mucosal surface or keratinized skin around the anus, buttocks or thighs.

Genital Herpes

The course of classic primary genital herpes is _____.

2-3 weeks

HSV keratoconjunctivitis is usually unilateral and is associated with _____.

blepharitis | tender preauricular lymphadenopathy

HSV encephalitis is an acute necrotizing infection involving the _____.

frontal and temporal lobes

HSV is a common cause of recurrent aseptic meningitis called _____.

Mollaret meningitis

Infants infected with HSV can present with _____.

1. skin, eyes, mouth involvement (SEM disease) 2, enncephalitis 3. disseminated infection

Infants with HSV encephalitis present at _____.

8-17 daysof life

HSV infection is confirmed with _____.

PCR

The gold standard for diagnosing HSV infection is _____.

viral culture

Treatment for HSV

Acyclovir Valacyclovir Famiciclovir

HSV Gingivostomatitis Treatment

Oral Acyclovir 15mkdose 5x/day PO x 7 days *max. 1 g/day

Herpes Labialis Treatment

Valacyclovir 2 g BID PO x 1 day Acyclovir 200-400 mg 5x/day PO x 5 days Famciclovir 1.5 g OD PO x 1 day

Herpes Gladiatorum Treatment

Acyclovir 200 mg 5x/day PO x 7-10 days | Valacyclovir 500 mg BID PO x 7-10 days

Herpetic Whitlow Treatment

Acyclovir 1.6-2 g mg/day BID/TID PO x 10 days

Eczema Herpeticum Treatment

Acyclovir 200 mg 5x/day PO x 5 day

Teatment Options for Recurrent HSV Infections

1 - no therapy 2 - episodic therapy 3 - long-term suppressive therapy

Herpes encephalitis should be treated with _____.

Acyclovir 10 mkdose q8 x 1h x 14-21 days

HSV limited to skin, eyes and mouth should be treated for _____.

14 days

Disseminated or CNS HSV should be treated for _____.

21 days

Pregnant women with active genital herpes should deliver via CS within _____.

4-6 hours of rupture of membranes

_____ infection results in establishment of of a lifelong latent infection of sensory ganglion neurons.

Varicella

Reactivation of latent varicella infection causes _____.

herpes zoster (shingles)

_____ ias n enveloped virus with double-stranded DNA genomes that encode 70 proteins.

Varicella

Primary varicella infectionresults from inoculation of the virus onto the _____.

upper respiratory tract mucosa | tonsillar lymphoid tissue

The incubation period of varicella is _____.

10-21 days

Varicella is contagious _____ before the appearance of rash.

1-2 days

Chickenpox manifests _____ after exposure.

14-16 days

The initial exanthem of _____ consists of intensely pruritic erythematous macules that evolve through the papular stage to form clear, fluid-filled vesicles.

varicella

Clouding and umbilication of varicella lesions begin in _____.

24-48 hours

While the initial varicella lesions are crusting, new crops form on the _____.

trunk then extemities

The distribution of varicella rash is _____.

central or centripetal

Varicella in vaccinated individuals is called _____ and is caused by _____.

Breakthrough Varicella | wild-type VZV

Breakthrough varicella is _____ than wild-type infection.

less contagious

_____ is a severe complication of primary VZV infection which manifests with visceral organ involvement, coagulopathy, severe hemorrhage and continued vasicular lesion development.

Progressive Varicella

Infants whose mothers demonstrate varicella in the period from _____ are at high risk for severe varicella.

5 days before to 2 days after delivery

Newborns from mothers with varicella should be given _____.

1 vial of VZIG

_____ is characterized by cicatricial skin scaring in a zoster-like distribution, limb hypoplasia, neurologic, renal and autonomic nervous system abnormalities.

Congenital Varicella

The characteristic cutaneous lesion of _____ has been called cicatrix, a zigzag scarring, in a dermatomal distribution associated with atrophy of the affected limb.

congenital varicella

Herpes zoster manifests as vesicular lesions in a _____ pattern.

dermatomal

The most common complication of herpes zoster is _____, a painful condition that affects the nerves despite resolution of the shingles skin lesions.

postherpetic neuralgia

In Varicella, multinucleated giant cells can be detected through _____.

Tzanck Smear

A _____ increase in varicella IgG is confirmatory of acute infection.

The drug of choice for varicella is _____.

Acyclovir 20 mkdose QID x 5 days *max. 800mg/dose

_____ is the only drug available for acyclovir-resistant VZV infections.

Foscarnet 120 mkday q8 x 3 weeks

The most common fatal complication of varicellla is _____.

pneumonia

Varicella is contagious for _____.

24-48 hours before rash

Varicella Vaccine Schedule

1st dose - 12-15 mos. | 2nd dose - 4-6 y.o.

Postexposure varicella prophylaxis is given within _____ after exposure.

3-5 days

_____ is the best known clinical syndrome caused by the Epstein-Barr Virus.

Infectious Mononucleosis

Infectious Mononucleosis is also known as _____.

glandular fever

_____ derives its name from the mononuclear lymphocytosis wih atypical appearing lymphocytes

Infectious Mononucleaosis

Infectious Mononucleosis-like illnesses can be caused by _____.

``` CMV Toxoplasma gondii adenovirus viral hepatitis HIV rubella ```

EBV affects _____ of the world's population.

95%

EBV is shed in _____ for _____ after acute infection then intermittently for life.

oral secretions, 6 mos.

Triad of EBV

fatigue pharyngitis generalized lymphadenopathy

The atypical lymphocytes that are characteristic of infectious mononucleosis are _____ which exhibit suppressor and cytotoxic functions that develop response to infeced B lymphocytes.

CD8+ T lymphocytes

____ was the first virus to be associated with malignancy

EBV.

EBV infection increases risk for _____ by 2-4x.

Hodgkin's Disease

____ is an X-linked recessive disorder of the immune system associated with severe, persistent and sometimes fatal EBV infection.

X-Linked Lymphoproliferative Syndrome | Duncan Syndrome

The incubation period of Infectious Mononucleosis is _____.

30-50days

Classic PE of Infectious Mononucleosis

generalized lymphadenppathy (90%) splenomegaly (50%) hepatomegaly (10%)

80% of infectious mononucleosis patients experience _____ when treated wtih ampicillin or amoxicillin.

ampicillin rash

EBV is associated with _____, a symmetric rash on the cheeks with multiple erythematous papules which may coalesce into plaques, and persists for 15-50 days.

Gianotti-Crosti syndrome

The culture method for EBV is _____.

transformation assay

_____ is performed by co-cultivation of oropharyngeal or genital secretions, peripheral blood (10-390 ml) or tumor with human umbilical cord lymphocytes.

Transformation Assay

EBV cultures are observed for 6 weeks for signs of _____.

cell transformation

EBV immortalizes the _____.

umbilical cord cells

In EBV infection, there is eukocytosis at _____ with _____ atypical lymphocytes.

10,000-20,000 cells/mm3 | 20-40%

Heterophile Antibody Test is useful for diagnosisng _____.

EBV infection

Paul-Bunnell-Davidson Test is used to detect Paul-Bunnell Antibodies to diagnose _____.

EBV

Because of risk for splenic rupture in EBV, strenuous activities must be avoided for _____.

2-3 weeks or while with splenomegaly

The most feared complication of EBV is _____.

subcapsular splenic hemorrhage or splenic rupture

Splenic hemorrhage or rupture in EBV is most likely to happen during the _____ of disease.

2nd week

_____ is associated with EBV and presents with perceptual distortions of sizes, shapes and spatial relationships.

Alice in Wonderland Syndrome (metamorphopsia)

_____ is the most common cause of congenital infection.

Cytomegalovirus (CMV)

CMV causes _____ which causes hepaatosplenomegaly, jaundice, petechia, purpura and microcephaly in neonates.

Cytomegalic Inclusion Disease

_____ is the largest of the herpesviruses and has a diameter of 200 nm with double-stranded DNA viral genome of 240 kb in a 64 nm core enclosed by an icosahedral capsid composed of 162 capsomers.

CMV

_____ causes SGA, microcephaly, thrombocytopenia, hepatosplenomegaly, hepatitis, intracranial calcifications, chorioretinitis, hearing abnormalities and blueberry muffin appearance.

CMV

HHV-6 is responsible for _____.

Roseaola Infantum Exanthema Subitum 6th Disease

_____ are the sole members of the Roseolovirus genus in the Betaherpesviridae subfamily of human herpesviruses.

HHV 6 and 7

_____ are composed of a protein-dense tegument, lipid envelope and icosahedral nucleocapsid containing large linear double-stranded DNA genomes with > 80 unique proteins

HHV 6 and 7

95% of children are infected with HHV 6 by _____.

2 y.o.

HHV 6 is traansmitted through _____.

transplacental infection | chromosomal integration

HHV 6 is unique among the human herpesviruses in that it is integrated in the _____ of the human chromosome.

telomere end

_____ viremia is demonstrated by co-culture of the patient's peripheral blood mononuclear cells (PBMCs) with mitogen-stimulated cord blood mononuclear cells.

HHV 6

_____ has a cytopathic effect consisting of appearance of large refractile mononucleated or multinucleated cells with intracytoplasmic and/or intranuclear inclusions.

HHV 6

_____ is characterized by the abrupt onset of high fever which may be accompanied by fussiness.

Roseola

_____ presents with fever lasting 72 hours with a faint pink or rose-colored, non-pruritic, 2-3 mm morbilliform rash on the trunk.

Roseola

In Asian counties, ulcers at the uvulopalatoglossal junction called _____ are commonlu seen in roseola.

Nagayama Spots

_____ is the most consistent finding in HHV 6 infection.

High Fever (39.7° C)

The most common laboratory findings in HHV 6 infeections are _____.

↓WBC 8900/mm3 ↓lymphocytes 3400/mm3 ↓neutrophils 4500/mm3

_____ presents as 3 days of high fever in an otherwise non-toxic (10 mo.) infant with blanching maculopapular rash on the trunk.

Roseola

_____ is the gold standard for diagnosisng roseola.

Viral Culture

_____ are the most common complication of roseola.

Convulsions

_____ is the major cause of bronchiolitis and viral pneumonia in children < 1 y.o. and is the most important respiratory tract pathogen of early childhood.

Respiratory Syncytial Virus (RSV)

_____ is an enveloped RNA virus with a single-stranded negative-sense genome that replicates entirely in the cytoplasm of infected cells and matures by budding from the apical surface of the cell membrane,

RSV

Because RSV has a non-segmented genome, it can undergo _____.G glycoprotein.

antigenic shift

Breastfeeding is protective against RSV in _____ infants.

female

RSV if the lower respiratory tract have the highest incidence during _____ of age.

6 weeks-7 mos.

_____ is caused by obstruction and collapse of the small airways during expiration

Bronchiolitis

Airway Resistance is proportional to _____.

1/radius^4

The first sign of RSV infection is _____.

rhinorrhea

RSV CXR Findings

normal (30%) hyperexpansion peribronchial thickening interstitial infiltrates

Definitive diagnosis of RSV infection is based on the detection of _____.

live virus in respiratory secretions by cell culture

_____ is an antiviral agent delivered through an oxygen hood, face masks or ET tube that can be used for RSV infection.

Ribavirin

Immunoprophylaxis for RSV

Palivizumab 15 mg/kg IM 1x/mo.

_____ is a neutralizing humanized murine monoclonal antibody against RSV.

Palivizumab

Canditates for RSV Immunoprophylaxis

lung disease preterm < 2 y.o. with CHD

_____ are non-enveloped viruses with an icosahedral capsid containing double-stranded DNA.

Adenoviruses (AdV)

Adenoviruses can be shed from the _____ for prolonged periods and can establish chronic infection of the _____.

GI tract | tonsils and adenoids

An important factor in adenovirus transmission is its ability to _____.

survive on inanimate objects in the environment

Hemorrhagic cystitis with sudden onset hematuria, dysuria, frequency, urgency and (-) urine bacterial culture can be caused by _____.

adenovirus

In early childhood, the single most important cause of severe dehydrating diarrhea is _____.

rotavirus

Medically Important Pathogens of Viral Gatroenteritis

Rotavirus Astrovirus Calicivirus (Norwalk Agent)

_____ are wheel-like, triple-shelled icosahedrons containing 11 segments of double-stranded RNA.

Rotaviruses

_____ are in the Reoviridae family and cause disease in virtually all mammals and birds.

Rotaviruses

Viruses that cause human diarrhea selectively infect and destry _____.

villus tip cells of the small intestines

Viral infection of intestinal villus tip cells leads to decreased absorption of _____ leading to an imbalance in the ratio of the intestinal fluid absorption to secretion.

salt and water

Viral infection of intestinal villus tip cells leads to dminished _____ acctivity and malabsorption of complex carbohydrates particularly _____.

disaccharidase, lactulose

Rotavirus has an incubation period of _____.

< 48 hours

Adenovirus enteritis causes diarrhea lasting _____.

10-14 days

_____ is the most common finding in severe viral enteritis.

Isotonic Dehydration with acidosis

Children may be infected with rotavirus each year during the _____.

first 5 years

Trivalent rotavirus vaccine has been linked to increased incidence of ______.

intussusception

_____ is characterized by biphasic fever, myalgia or arthraalgia, rash, leukopenia and lymphadenopathy.

Dengue Fever

Dengue viruses have _____ distinct antigenic types.

Dengue is transmitted bby _____, a daytime biting mosquito.

Aedes aegypti

_____ is the strongest risk facor for developing severe dengue.

Infection-Enhancing Antibodies

The incubation period of dengue is _____.

1-7 days

In dengue, severe back pain can precede fever. this is called _____.

breakback fever

A generalized, blanching, macular rash may be seen in the first _____ of dengue fever.

24-48 hours

_____ after defervescence from dengue, a generalized, morbiliform, maculopapular rash appears that spares the palms and soles.

1-2 days

WHO Criteria for Dengue Hemorrhagic Fever

``` fever - 2-7 days, biphasic hemorrhagic manifestations thrombocytopenia (< 100,000/mm3) increased capillary permeability ≥ 20% increase in hemetocrit pleuraleffusion or ascites hypoalbuminemia ```

Criteria for Dengue Shock Syndrome

hypotension tachycardia narrow pulse pressure (≤ 20 mmHg) poor perfusion

Dengue IgM disappears after _____.

6-12 weeks

In dengue fever, pancytopenia may occur after the _____ of illnesss.

3-4 days

Most Common Hematologic Abnormalities in Dengue

≥ 20% increase in hemetocrit thrombocytopenia prolonged bleeding time decreased prothrombin level

Most Frequent Complications of Dengue

fluid and electrolyte losses hyperpyrexia febrile convulsions

The _____ virus is a bullet-shaped, negative-sense, single-stranded, enveloped RNA virus from the family Rhabdoviridae, genus Lyssavirus.

rabies

After inoculation, the rabies virus replicates slowly and at low levels in the _____.

muscle | skin

The rabies virus enters the _____, utilizing the _____.

peripheral motor nerve | nicotinic acetylcholine receptor

Oncein the nerve, the rabies virus travels by _____, crossing synapses roughly every _____.

fast axonal transport, 12 hours

Rabies infection concentrates in the _____, accounting for autonomic dysfunction and sparing of cognition.

brainstem

The pathologic hallmark of rabies, the _____, is composed of clumped viral nucleocapsids that create cytoplasmic inclusions on histology.

Negri body

After infection of the CNS, the rabies virus travels _____ throug the peripheral nervous system.

anterograde

The incubation period of rabies is _____.

1-3 mos.

Forms of Rabies

Encephalopathic/Furious | Paralytic/Dumb

_____ are cardinal signs of rabies.

hydrophobia | aerophobia

_____ is the most sensitive available assay for the diagnosis if rabies.

RT-PCR

Rabies post-Exposure prophylaxis

1. cleanse wound 2. Human RIG 20 IU/kg 3. inactivated vaccine

_____ is a single-stranded RNA virus of the retrovirus family that produces a reverse transcriptase enabling the viral RNA to act as a template for DNA transcription and integration into the host gene.

Human Immunodeficiency Virus (HIV)

HIV infects _____.

helper T cells | cells of the monocyte-macrophage lineage

HIV infects cells via interaction of _____ with _____.

viral protein gp120, CD4 and chemokines

HIV causes _____ immunodeficiency.

combined (B and T cell)

HIV is transmitted through _____.

sexual contact IV drug use birth breastfeeding

Perinatal transmission of HIV can be decreased from 25% to 8% with _____.

maternal antiretrovirals before and during delivery | postnatal treatment of the infant

Incubation Period of HIV: | Vertical Transmission

5 mos. (1-24 mos.)

Incubation Period of HIV: | Horizontal transmission

7-10 years

Primary HIV infection results in the _____ which develops after 2-6 weeks and consists of fever, malaise, weight loss, pharyngitis, lymphadenopathy and maculopapular rash.

Acute Retroviral Syndrome

Manifestations of HIV in Children

``` recurrent bacterial infection lymphoid hyperplasia chronic parotid swelling lymphocytic interstitial pneumonitits early onset of progressive neurologic deterioration ```

HIV can be diagnosed by _____.

1-6 mos.

Diagnostic HIV testing should be done at _____.

48 hours 1-2 mos. 3-6 mos.

The preferred test for HIV is _____.

HIV DNA PCR

Persistence of a (+) HIV antibody test beyond _____ indicates hIV infection.

18 mos.

There is rapid increase of HIV risk as CD4 counts declines to _____.

< 15%

Initiation of antiretroviral therapy is recommended for _____.

infants < 12 mos. with clinical or immunologic symptoms of HIV, > 12 mos. with AIDS or severe immunosupression, HIV RNA levels > 100,000 copies/ml, adolescents with CD4< 200-350/mm3 or HIV RNA levels > 55,000 copies/ml

Antiretroviral Drugs

nucleoside analogue nucleoside reverse transcriptase inhibitors non-nucleoside reverse transcriptase inhibitors protease inhibitors fusion inhibitors

Combination therapy with _____ is recommended for HIV.

Highly Active Antiretroviral Therapy (HAART)

Infants born to HIV (+) mothers should be given prophylaxis for P. jirovecii (carinii) pneumonia with _____ given at _____.

TMP-SMX, 4-6 weeks to 1 y.o.

TMP-SMX prophylaxis for P. jirovecii (carinii) should be given to older children with _____.

CD4 < 200/mm3 | oropharyngeal candidiasis

HIV (+) individuals are prone to Non-Hodgkin Lymphoma most commonly found at the _____.

GI tract

_____ are the 2nd most common tumors among HIV-infected children.

Leiomyosarcomas

Maternal HIV Prophylaxis

Zidovudine 100 mg 5x/day PO starting at 4 weeks AOG to delivery (2 mg/kg IV as LD then 1 mg/kg/h)

Neonatal HIV Prophylaxis

Zidovudine 2 mg/kg q6 for the first 6 weeks

Most Commen Diseases caused by E. histolytica

amebic colitis | amebic liver abscess

Amebiasis is acquired through ingestion of _____ which measure 10-18 mm in diameter in contain 4 nuclei.

parasite cysts

The most common finding in amebic liver abscess is _____.

single abscess in the right hepatic lobe

Invasive amebiasis is treated with _____.

Nitriimidazole (Metronidazole, Tinidazole) | Luminal Amebicide

Giardia lamblia infects humans after ingestion of _____ which measure 8-10 mm in diameter.

10-100 cysts

The incubation period of Giardia is _____.

1-2 weeks

_____ infection causes stools which are initiallly watery then later becomes greasy and foul smelling and may float.

Giardia

The diagnostic tests of choice for Giardia are _____.

stool enzyme immunoassay (EIA) | direct fluorescent antibody tests

Drug of Choice for Giardia

Tinidazole Nitazoxanide Metronidazole

Major Phases of the Life Cycle of Plasmodium

Asexual (Schizogony) | Sexual (Sporogony)

The _____ of Plasmodium asexual development begins when the merozoites released from exoerythrocytic schizonts in the liver penetrate erythrocytes.

Erythrocytic Phase

When inside the erythrocyte, plasmodium transforms into _____ which enlarges to become a _____.

ring form, trophozoite.

Trophozoites can be identified via _____ which is the primary means of confirminf the diagnosis of malaria.

Giemsa Stain of blood smear

Malaria is primarily transmitted by _____.

female Anopheles mosquitoes

_____ is the most important cause of fever and morbidity in the tropical world.

Malaria

The incubation period of plasmodium is _____ depending on the species.

6-30 days

The most characteristic clinical feature of malaria is _____.

febrile paroxysms

Classic Symptoms of Febrile Paroxysms in Malaria

high fever rigors sweats headache

Febrile paroxysms coincide with the rupture of _____.

schizonts

Plasmodium with Tertian Periodicity (48 hours)

P. vivax, P. ovale

Plasmodium with Quartan Periodicity (72 hours)

P. malariae

_____ is the recurrence of malarial symptoms after a primary attack that is due to the survival of erythrocyte forms in the bloodstream.

Short-Term Relapse

_____ is the renewal of malarial symptoms long after the primary attack, usually due to release of merozoites from an exoerythrocytic source in the liver.

Long-Term Relapse

Malaria Diagnostics: | scan large numbers of erythrocytes quickly

thick blood smear

Malaria Diagnostics: | identification of malaria species

thin blood smear

_____ is the recommended treatment for malaria.

Chloroquine

_____ is a complication of P. falciparum and a frequent cause of death.

Cerebral Malaria

Severe hemolysis caused by malaria is called _____.

blackwater fever

_____ is a sepsis syndromewith vascular collapse caused by malaria.

Algid Malaria

Malaria prophylaxis should be given _____.

1-2 weeks before until 4 weeks after travel

Doxycycline can be given as malaria prophylaxis _____ before travel.

1-2 days

In areas where chloroquine-resistant P. falciparum exists, _____ is recommended.

Mefloquine

Exoerythroxytic Cycle: | P. falciparum

5.5-7 days

Exoerythroxytic Cycle: | P. vivax

6-8 days

Exoerythroxytic Cycle: | P. ovale

9 days

Exoerythroxytic Cycle: | P. malariae

12-16 days

Exoerythroxytic Cycle: | P. knowlesi

8-9 days

Erythrocytic Cycle: | P. falciparum

48 hours

Erythrocytic Cycle: | P. vivax

42-48 hours

Erythrocytic Cycle: | P. ovale

49-50 hours

Erythrocytic Cycle: | P. malariae

72 hours

Erythrocytic Cycle: | P. knowlesi

24 hours

Incubation Period: | P. falciparum

12 days (9-14 days)

Incubation Period: | P. vivax

13 days (12-17 days)

Incubation Period: | P. ovale

17 days (16-18 days)

Incubation Period: | P. malariae

28 day (18-40 days)

Incubation Period: | P. knowlesi

~12 days

Erythrocyte Preference: | P. falciparum

young erythrocytes

Erythrocyte Preference: | P. vivax

reticulocytes

Erythrocyte Preference: | P. ovale

reticulocytes

Erythrocyte Preference: | P. malariae

older erythrocytes

Erythrocyte Preference: | P. knowlesi

older erythrocytes

Parasite Load: | P. falciparum

1-5

Parasite Load: | P. vivax

1-2

Parasite Load: | P. ovale

1-2

Parasite Load: | P. malariae

1-2

Parasite Load: | P. knowlesi

variable

Secondary Exoerythrocytic Cycle and Relapses: | P. falciparum

absent

Secondary Exoerythrocytic Cycle and Relapses: | P. vivax

present

Secondary Exoerythrocytic Cycle and Relapses: | P. ovale

present

Secondary Exoerythrocytic Cycle and Relapses: | P. malariae

absent

Secondary Exoerythrocytic Cycle and Relapses: | P. knowlesi

absent

Duration of Untreated Infection: | P. falciparum

1-2 years

Duration of Untreated Infection: | P. vivax

1.5-4 years

Duration of Untreated Infection: | P. ovale

1.5-4 years

Duration of Untreated Infection: | P. malariae

3-50 years

Duration of Untreated Infection: | P. knowlesi

unknown

Severity of Primary Attack: | P. falciparum

severe | medical emergency

Severity of Primary Attack: | P. vivax

mild to severe splenic rupture relapse

Severity of Primary Attack: | P. ovale

mild splenic rupture relapse

Severity of Primary Attack: | P. malariae

chronic subclinical nephritis

Severity of Primary Attack: | P. knowlesi

variable | can be fatal

Periodicity of Febrile Attacks: | P. falciparum

none

Periodicity of Febrile Attacks: | P. vivax

48 hours (tertian)

Periodicity of Febrile Attacks: | P. ovale

48 hours (tertian)

Periodicity of Febrile Attacks: | P. malariae

72 hours (quartan)

Periodicity of Febrile Attacks: | P. knowlesi

24 hours

Duration of Febrile Paroxysm: | P. falciparum

16-36 hours

Duration of Febrile Paroxysm: | P. vivax

8-12 hours

Duration of Febrile Paroxysm: | P. ovale

8-12 hours

Duration of Febrile Paroxysm: | P. malariae

8-10 hours

Duration of Febrile Paroxysm: | P. knowlesi

unknown

Toxoplasmosis is a zoonosis caused by _____ an intracellular protozoan parasite.

Toxoplasma gondii

T. gondii is acquied by ingesting _____.

oocysts - cats | cysts - unndercooked meat

_____ is characterized by heterophil (-) mononucleosis syndrome that includes lymphadenopathy, fever and hepatosplenomegaly

Toxoplasmosis

Serologic diagnosis is established by (+) PCR for T. gondii in _____.

peripheral WBCs CSF serum amniotic fluid

Toxoplasmosis is treated with _____.

Pyrimethrine Sulfadiazine *folic acid inhibitor, should be given with folinic acid

Ascariasis is caused by _____, a large nematode.

Ascaris lumbricoides

_____ is the most prevalent helminthiasis.

Ascariasis

After humans ingest ascaris eggs, larvae are released and penetrate the _____.

intestines → lungs → trachea → reswallowed

_____ occurs as ascaris larvae migrate through the lung, producing cough, blood-stained sputum, eosinophilia and transient infiltrates on CXR.

Pulmonary Ascariasis

_____ is diagnostic for ascariasis.

Fecalysis

Pinworm is caused by _____, a nematode that is distributed worldwide.

Enterobius vermicularis

Enterobius eggs hatch in the _____. and the larvae migrate to the _____.

stomach, cecum

The most common symptoms of enterobasis are _____.

nocurnal anal pruritus (pruritus ani) | sleeplessness

Enterobius eggs are detected by _____.

presssing cellophane tape over the anus to collect eggs

Enterobiasis is treated with_____.

Albendaole 400 mg Mebendazole 100 mg Pyrantel pamoate 11 mg/kg (max. 1 g) *single dose, q2 weeks