Infectious Diseases COPY Flashcards
Criteria for Fever of Unknown Origin (FUO)
rectal T ≥ 38° C
cause could not be identified
3 weeks - OPD
1 week - hospital
FUO in Neonates
7% risk of having serious bacterial infection
FUO at 1-3 mos.
pyelonephritis - most common
FUO at 3 mos. - 3 y.o.
viral infection
_____ are connective tissue diseases most commonly associated with FUO.
JIA, SLE
Empirical treatment for FUO should be avoided except in _____.
anti-TB drugs for the critically ill
_____ is an aerobic, G (+), coagulase (+) bacteria that grows in pairs or clusters.
Staphylococcus aureus
_____ is the most common cause of pyogenic infection of the skin and soft tissue
S. aureus
Adhesion of S. aureus to mucosal cells is mediated by _____ in the cell wall.
teichoic acid
Staphylococci produce a _____ which may interfere with opsonophagocytosis.
slime layer
loose polysaccharide capsule
_____ is present in S. aureus and absorbs serum Ig, preventing antibacterial antibodies from acting as opsonins.
Protein A
Enzymes Elaborated by Staphylococci
catalase
penicillinase or β-lactamase
_____ 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)
S. aureus with _____ is associated with more severe and invasive skin disease, pneumonia and osteomyelitis.
Panton-Valentine Leukocidin (PVL)
_____ in S. aureus produce dermatologic manifestations by splitting the desmosome and altering the intracellular matrix in the stratum granulosum.
Exfoliatins A and B
S. aureus can produce _____ distinct enterotoxins.
≥ 20
_____ are the most common causes of food poisoning from S. aureus.
Enterotoxin A and B
_____ is associated with TSS related to menstruation and focal staphylococcal infection.
Toxic Shock Syndrome Toxin 1 (TSST-1)
_____ 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)
An altered _____ is responsible for the methicillin resistance of MRSA isolates.
PBP-2A
protein binding proteins
_____ that complicates viral croup may be caused by S. aureus.
Membranous Tracheitis
S. aureus often causes _____ that may be associated with empyem, pneumatocoeles, pyopneumothorax and bronchopleural fistulas.
necrotizing pneumonitis
Localized staphylococcal abscesses in muscle is called _____.
pyomyositis.
_____ is the most common cause of osteomyelitis and suppurative arthritis in children.
S. aureus
_____ 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
No
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
No
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
- documentation of adequate vacccination
- labortory evidence
- birth before 1957
- 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 _____.
- skin, eyes, mouth involvement (SEM disease)
2, enncephalitis - 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.
4x
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.
4
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
- cleanse wound
- Human RIG 20 IU/kg
- 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
