Infectious Disease Flashcards
1
Q
General criteria for fever of unknown origin
A
fever >38.3 C (100.9F)
at least 3 wks duration
no hx after 3 outpt visits or 3 d hospitalization
2
Q
Most common etiologies for FUO
A
infx
malignancy
CTD
3
Q
What meds can cause fever?
A
antimicrobials H1 and H2 blocking antihistamines anti-epileptics Iodides NSAIDs antihypertensives antiarrhythmics
4
Q
What kind of dx testing should you do in pt with FUO?
A
blood cultures x3
blood chem
UA
Other labs: i.e. ESR/CRP, TB testing, HIV abs, stool cx, etc.
Imaging
5
Q
What should you do with FUO pts with CNS s/s?
A
CSF
head and or spine imaging
6
Q
What should you do with FUO pts who have traveled to midwest or west recently?
A
test for histoplasmosis, cocci
7
Q
What should you do with FUO pts who have traveled to malaria endemic areas?
A
thick and thin blood smears
8
Q
What should you do with FUO pts who have hx of trauma or infx
A
possible thrombophlebitis-venous duplex imaging
9
Q
Management of FUO?
A
be concern with weight loss/consitutional s/s
+/- ID consult
+/- admit
10
Q
General info on staph infx
A
nose is main site of colonization
seen in clusters on gram stain
catalase positive
beta-hemolytic
11
Q
What is coagulase test used for?
A
to identify which species of Staph is growing
-only s. aureus will be coagulase positive
12
Q
Staph can cause….
A
lots of infections!
abscess, pyogenic infections, toxic shock syndrome, H-PNA, folliculitis, cellulitis, impetigo, conjuctivitis
13
Q
What is MRSA?
A
Methicillin-resistant Staphylococcus aureus
Most Staphylococci are resistant to penicillin due to production of penicillinase
14
Q
Staph eidermidis?
A
part of normal body flore
freq. skin contaminant of blood cultures
causes infx of: urine cath, IV lines, prosthetic joints/heart valves
15
Q
Etiology of toxic shock syndrome? path?
A
toxin produced by s. aureus
toxins are “superantigens”
16
Q
Clinical presentation of TSS?
A
Abrupt onset of high fever
V/watery D
Sore throat, myalgias, HA
Hypotension with kidney and heart failure
Diffuse macular erythematous rash and nonpurulent conjunctivitis
Desquamation, esp. of palms & soles (late finding)
17
Q
Labs with TSS?
A
findings c/w shock and organ failure
18
Q
Tx for TSS?
A
rapid rehydration
anti-staphylococcal drugs- clindamycin + vancomycin
manage kidney/HF
remove/address source of toxin
19
Q
What is staph scaled skin syndrome (SSSS)
A
toxin released by staphylococcus aureus
causes loss of cell-to-cell adhesion between keratinocytes leading to intra-epidermal splitting
20
Q
SSSS is most common among?
A
neonates 3-15 days old
21
Q
Clinical presentation for SSSS?
A
Prodrome: fever, irritability
Erythematous patches with large superficial fragile blisters
- When blisters rupture, skin appears red and scalded
- Nikolsky’s sign
22
Q
etiology of SSSS v. TEN
A
TEN usually related to med use
23
Q
Dx of SSSS?
A
cultures
skin biopsy-shows intraepidermal cleavage without necrosis
24
Q
Tx for SSSS?
A
Penicillinase-resistant beta-lactam agents
-If no response, consider MRSA & tx with vancomycin
Temperature regulation
Fluid resuscitation
Analgesia
Sterile dressings
Prevent secondary infections
25
Etiology of anthrax?
Bacillus anthracis
Gram-positive rod, produces spores
Routes of entry: GI tract, skin, inhalation, direct injection
bioterrorism w/ antrax spores
26
What is the MC form of anthrax? describe this
cutaneous clinical syndrome
5-7 day incubation
Usually an exposed areas
Small, painless, pruritic papules that quickly enlarge and develop a central vesicle or bulla > erosion, leaving a painless necrotic ulcer with a black, depressed eschar
Surrounding tissue often has extensive edema + regional LAD and lymphangitis
27
Hallmark finding for antarx-cutaneous clinical syndrome
eschar w/ extensive surrounding edema
28
Systemic sxs of cutaneous clinical syndrome anthrax?
fever, malaise, HA
29
Pathophys of anthrax inhalation clinical syndrome?
-Spores phagocytosed by alveolar macrophages & transported to mediastinal lymph nodes >
spores germinate, multiply, release toxins >
Toxins cause hemorrhagic necrosis of thoracic lymph nodes draining the lungs>
Causes hemorrhagic mediastinitis +/- necrotizing pneumonia >
bacteremia +/- meningitis
30
Incubation for anthrax inhalation clinical syndrome
1-7 days
then prodrome and fulminant phases
31
Prodrome of anthrax inhalation clinical syndrome
```
Myalgia
Fever
Malaise
Nausea
Hemoptysis
Dyspnea
Odynophagia
Chest pain
Lasts 4-5 days
```
32
Fulminant phase of anthrax inhalation clinical syndrome
```
Progressive respiratory symptoms
Severe dyspnea
Hypoxemia
Shock
Death within days
```
33
CXR consistent with anthrax inhalation clinical syndrome
Widened mediastinum **classic
Hilar abnormalities
Pulmonary infiltrates or consolidation
Pleural effusion
34
What are the 2 forms of GI tract clinical syndrome anthrax?
oropharyngeal or gastrointestinal
35
Etiology of GI tract anthrax?
From consumption of undercooked, infected meat from animals infected with anthrax
36
Clinical course of GI anthrax? Intubation period?
Incubation: 1-6 days
Necrotic ulcers surrounded by edema of infected intestinal segment and adjacent mesentery >
Enlarged and hemorrhagic mesenteric lymph nodes
Ulcerations in stomach, esophagus, duodenum can cause GI hemorrhage
37
Dx work up for anthrax?
Culture
Immunohistochemical staining
Molecular testing: PCR, anti-protective antigen IgG detected on ELISA
+/- LP to r/o meningitis
38
Tx for anthrax?
report to public heath
antimicrobial therapy: Cipro + another abx based on type
anti-toxin
Adjunctive therapy
-i.e. +/- steroids, ascites drainage...
39
What are some of the anti-toxins use for anthrax?
Monoclonal antibody: raxibacumab or obiltoxaximab
Anthrax immunoglobulin
40
prevention for anthrax?
post expose prophylaxis for those exposed to aerosolized B. anthraxis
cutaneous-watch for lesion
GI exposure: +/- 7-14 d course of prophylaxis
41
Etiology of rabies?
rhabdovirus
42
How is rabies transmitted?
infected saliva, usually from animal bite
-bats, racoons, skunks
43
Incubation period for rabies?
usually 3-7 wks, can be 10d-yrs
44
Patho of rabies?
Virus travels in nerves to the brain, multiplies in brain, then travels along efferent nerves to salivary glands
Forms cytoplasmic inclusion bodies – site of viral transcription & replication
45
Clinical presentation for rabies?
pain at bite site
Prodrome: fever, malaise, HA, N/V
then: percussion myoedema
CNS presentation- both progress to coma, ANS dysfunction, death
46
What are the two dif CNS presentations for rabies?
"furious” – encephalitic *MC
-terrror, hydrophobia, muscle spasms, panics, cardiac arrest
“dumb” – paralytic
-less dramatic, gradual coma, paralysis
47
Dx for rabies?
test animal is poss.
involve health department
PCR of saliva -> RNA
viral cx of saliva
full thickness skin biopsy
anti rabies abs in serum and CSF
48
Prevention for rabies?
immunize pets or ind. with sig. risk
Thoroughly cleanse, debride, and flush wounds with soap and water
vaccines: PEP, PrEP
49
Px for rabies?
once sxs > likely death within 7 d
ICU
manage airway, o2, control seizures
50
Etiology of zika virus?
arthropod-borne falivivirus
transmitted via aedes species mosquitos
can be transmissted sexually once infx, vertical transmission
51
presentation on zika virus?
Acute onset fever, maculopapular pruritic rash, nonpurulent conjunctivitis, arthralgias
for up to 7d.
(only 20% have sxs)
52
Dx for zika virus?
viral RNA or IgM
real time RT-PCR of blood or urine for zika virus RNA
test asxs preg women for IgM 2-12 wks after travel to enemic area of sex with infx. partner
53
management of zika virus? `
Monitor serial US at 3-4 wk intervals for fetal anatomy and growth (congenital microcephaly)
54
What are some comp of zika virus?
GBS, myelitis, meningocephalitis
55
Prevention of zika virus?
Mosquito control
Avoid travel to affected areas when pregnant
Abstinence from sex or barrier protection
No blood donations
56
Etiology of legionella?
Legionella pneumophila
-Aerobic, gram-negative bacilli
Water reservoir contamination
Transmission is never person-to-person
57
RF for legionella?
cigarette smoking, chronic lung disease, older age, transplant recipient, biologic therapy
58
What are the 2 clinical syndromes of legionella?
legionnaire disease-pna
pontiac fever
59
clinical presentation of legionella?
Cough
Initially mild and slightly productive
Blood-streaked sputum but rarely gross hemoptysis
+/- chest pain
GI symptoms: N/V/D, abdominal pain
Lethargy, h/a, occasionally stupor
Chills, fever, dyspnea
60
PE for legionella?
consistent with pna
61
Work up for legionella?
```
Labs:
Renal/hepatic dysfunction
Thrombocytopenia
Leukocytosis
Hypophosphatemia
Hyponatremia
Hematuria/proteinuria
Elevated serum ferritin
```
CXR
62
Presentation for pontiac fever?
Mild form of Legionella infection
Fever, malaise, chills, fatigue, h/a
No respiratory complaints
Self-limited
63
Rare form of legionella that may be seen in immunocompromised?
Extrapulmonary disease
64
dx of legionella?
Hyponatremia, elevated liver enzymes, elevated CK
Sputum culture
Special media
Urinary antigen tests
65
Tx for legionella?
Azithromycin or
Clarithromycin or
FQ (levofloxacin)
x 10-14 days
Pontiac fever only needs symptomatic treatment
Isolation not necessary
66
Etiology of botulism?
Botulinum toxin produced by
Clostridium botulinum
Gram-positive, rod-shaped, spore-forming, obligate anaerobe
Found in soil
67
Path of botulism?
Blocks release of acetylcholine at the neuromuscular junction
-effects motor and sensory neurons, striated and smooth muscles
68
What are the 3 forms of botulism?
food borne > ingesting toxin from canned food (home canning )
infant > dust or honey
wound > IVDA
69
clinical presentation of botulism?
bi cranial neuropathies assoc. with descending weakness
-no fever
CN involvement: blurred vision, diplopi, nystagmus, ptosis
smooth muscle paralysis
paralysis may progress to res. failure
70
Dx of botulism?
clinical dx!
EMG to r/o MG
toxin in serum, stool, wound, food sources
71
Tx for botulism?
report to CDC
-equine serum heptavalent botusim antitoxin
intubation, mechanical vent
parenteral fluids or alimentation
72
etiology of diphtheria?
Gram positive bacillus, Corynebacterium diphtheriae
Exotoxin causes myocarditis and neuropathy
73
Diphtheria affects...
any mucous membrane or skin wound
Primarily respiratory tract
74
Clinical presentation of diphtheria?
Nasal – nasal discharge
Laryngeal – upper airway & bronchial obstruction
Pharyngeal – **MC, gray membrane covering tonsils & pharynx, mild sore throat, fever and malaise
Cutaneous - chronic, nonhealing sores or shallow ulcers with dirty gray membrane
75
Comps of diphtheria?
myocarditis- arrhythmias, heart block, HF
neuropathy- diplopia, slurred speech, dysphagia
76
Dx of diphtheria?
clinical!
can confirm with culture/assay
elevated WBC, proteinuria
77
Tx for diphtheria?
Diphtheria equine antitoxin
Penicillin or erythromycin x 14 days
Remove membrane by direct laryngoscopy or bronchoscopy
Airway management
Monitor EKGs/cardiac enzymes
Respiratory droplet isolation until negative culture x 3 of oropharynx
78
Prevention for diphtheria?
Diphtheria toxoid immunization
PEP
-booster + penicillin or erythromycin
79
What is tetanus? etiology?
nervous system disorder
Obligate anaerobe, Clostridium tetani
Found in soil
After inoculation, transforms into vegetative rod-shaped bacterium producing tetanus toxin
80
Patho of tetanus?
Retrograde axonal transport within motor neuron
Blocks neurotransmission, inactivating inhibitory neurotransmission > increased muscle tone, painful spasms, widespread autonomic instability
81
Presentation of tetanus?
incubation~8 d
4 clinical patterns:
Generalized: MC/severe- tonic contraction of skeltal muscle s
Local: tonic/spastic muscle contractions in one region
Cephalic: involve CNs
Neonate: poor feeding, dif. opening mouth, cessation of suckling
82
Dx of tetanous>
clinical + hx of inadequate immunization
83
Tx of tetanus?
ICU:
wound management
Metronidaxole
immune globulin, immunization x 3
benzos
neuromuscular blocking agents
airway management, nutritional support, PT
84
Prevention of tetanus?
immunization
update tetanus if punc. wound.
85
Etiology of lyme disease?
Spirochete, Borellia burgdorferi
86
Epidemiology of lyme disease
highest in 5-10 and 35-55
M >W
usually in mid atlantic, northeaster and north central US
87
How is lyme disease transmitted
tick-borne disease in US
Animal reservoir – white-footed mouse and deer
MC in spring and summer
tick needs to feed for 24-36 hours
88
early manifestations of lyme disease?
erythema migrans- 1 wks after bite
viral like illness
cardiac involvement
neuro involvement
conjunctivitis, keratitis, panophthalmitis
89
late manifestations of lyme disease
musculoskeletal- in large joints
neuro > encephalopathy, polyneuropathy
90
Dx criteria for lyme disease?
- exposure to tick bite
- erythema migrans
OR
- at least one late manifestation
- ELISA ab test > Western blot
91
Labs for lyme disease?
ESR
LFTs (mild abn)
mild anemia, leukocytosis, and microscopic hematuria
92
Tx for lyme disease? Tx in pregnant women?
Doxy 10-14 days
Amoxicillin
93
Px for lyme disease
most will do well and will have a complete recovery
pregnancy: concern for SA, still birth, preterm birth
some pts with have chronic sxs for mos: fatigue, arthralgias
94
What is post-lyme syndrome or "chronic lyme disease"
Nonspecific symptoms of fatigue, arthralgias, myalgias, headaches, memory disturbances, and cognitive impairment that can persist for months
- hx of lyme
- continued sxs after tx
95
Prevention for lyme disease?
Avoid exposure- repellants, clothing
Prophylactic abx if:
- tick attached for at least 36 hrs
- abx can be started when tick removed
- > 20% ticks known to be infx in area
- no contraindications for doxy
96
Etiology of rocky mountain spotted fever?
Tick-borne illness – Rickettsia rickettsia
gram neg, obligate intracellular bacterium
97
Vectors for rocky mountain spotted fever?
American dog tick, rocky mountain wood tick, brown dog tick
98
Epidemiology of rocky mountain spotted fever
M >W , children <10 and 40-64
MC in rural and suburban
spring and early summer
99
Clinical presentation for Rocky mountain spotted fever
Incubation period: 2-14 days
Fever, h/a (severe), rash, malaise, myalgias, arthralgias
rash: blanching erythematous rash with macules that transition to petechia
100
labs concerning for rocky mountain spotted fever? What else can you check?
Normal WBC count with immature bands
Thrombocytopenia
Hyponatremia
Elevated LFTs
Serologic testing
skin biopsy
101
Tx for rocky mountain spotted fever?
start tx within 5 days of onset
doxy preferred
102
Comps of rocky mountain spotted fever?
renal failure, sepsis, encephalitis, ARDS, etc.
103
Etiology of EBV? transmission?
herpes virus
initiate contact with saliva of infected persons
104
EBV can be assoc with development of...
B cell lymphomas, Hodgkin lymphoma, nasopharyngeal carcinomas, and gastric tumors
105
EBV-infectious mononucleosis presentation?
1-2 week prodrome: malaise, h/a, low grade fever
Classic symptoms: tonsillitis/pharyngitis, cervical LAD, fever
resolves in 1-2 wks, fatigue mos
106
What can happen if you tx infectious mononucleosis with a penicillin?
morbilliform rash
107
Dx for infectious mono?
CBC: lymphocytosis +/- neutropenia, thrombocytopenia
elevated LFTs
Heterophile ab test (monospot)
EBV specific abs
- IgM and IgG > acute infx
- Nuclear antigen > excludes acute infection
108
What are a few of the comps of mono?
splenic rupture
airway obstructions
109
Tx for infectious mono?
supportive!
corticosteroids
antivirals
sports restrictions
110
Etiology of cytomegalovirus?
herpes virus family
latent infx after resolution of acute infx
111
How is cytomegalovirus transmitted?
sexual exposure, close contact, blood/tissue exposure, perinatal
112
Presentation of cytomegalovirus?
immunocompetent- asxs
CMV mono MC in immunocompromised pts
In pregnancy, can occasionally be associated with syndrome of congenital CMV in newborns
113
Common presentation of CMV in aids pts?
retinitis
114
Dx for CMV? tx?
quantitative DNA PCR
Ganciclovir, valganciclovir, foscarnet, cidofovir
115
Etiology of toxoplasmosis? Host?
intracellular protozoan parasite, Toxoplasma gondii
Cat, transmitted through feces
116
Transmission of toxoplasmosis?
consumption contaminated food/water or poorly cooked meat form inf animal
vertical
organ transplant
117
Presentation of toxoplasmosis?
immunocompetent = usually asxs
MC: bi symmetrical or occipital adenopathy
fever, chills, HA
chorioretinitis
118
Why is toxoplasmosis important to recognize in preg pts? concern in immunocompromised?
TORCH
SAB, still birth, neonatal disease
concern for reactivated > comps
119
dx for toxoplasmosis?
serology- ELISA
mild lymphocytosis +/- atypical cells, elevated LFTs, increased CRP
120
Tx for toxoplasmosis?
most dont need tx
****100
121
Prophylaxic tx for toxoplasmosis? prevention?
Trimethoprim-sulfamethoxazole
122
Etiology of cryptococcosis?
Cryptococcus neoformans
Encapsulated budding yeast found in soil and on dried pigeon dung
Transmitted by inhalation
123
Presentation of cryptococcosis?
usually asxs in immunocompetent
Immunodeficiency: progressive lung disease and dissemination
Skin – papules, plaques, abscesses, sinus tracts
MSK – osteolytic lesions
124
Dx for cryptococcosis?
Respiratory secretion or pleural fluid culture
LP
MRI
Antigen testing
125
Tx for cryptococcosis?
Amphotericin B x 14 days
Follow with fluconazole x 8 weeks
126
How is VZV transmitted?
Varicella: respiratory droplets
Zoster: direct contact with lesions
127
RF for VFV?
```
Age > 50
Physical trauma
Underlying malignancy
Depression
Immunodeficiency
Chronic lung or kidney disease
```
128
Describe rash in VZV?
Erythematous papules that evolve into grouped vesicles or bullae; become pustular or hemorrhagic within 3-4 days
129
Other sxs of VZV?
acute neuritis, pain before rash
130
Dx of VZV?
usually clinical
| PCR testing
131
Tx for VZV?
anti-viral therapy
- within 72 hours of onset
- immunocompromised
- Rx: acyclovir
Analgesia
132
Prevention for VZV?
keep rash covered
proper hygiene
avoid contact with preg. women, premies, immunocompromised
Herpes zoster vaccine for those 50+
133
Tx for zika virus?
supportive
