Infectious Disease Flashcards
IE: Factors associated with increased risk of embolization
S. aureus IE, mobile vegetations >10 mm in diameter, and infection involving the mitral valve anterior leaflet
Definite IE requires:
2 major criteria or
1 major 3 minor or
5 minor
Possible IE definition:
1 major + 1 minor or
3 minor
Definition of “evidence of endocardial involvement” in Duke criteria
Positive echocardiogram:
- Oscillating intracardiac mass on valve or supporting structures or in the path of regurgitant jets or in implanted material, in the absence of an alternative anatomic explanation, or
- Abscess, or
- New partial dehiscence of prosthetic valve,
or
New valvular regurgitation (increase or change in preexisting murmur not sufficient)
Negative TEE but IE still likely, next dx step:
Repeat TEE in 7-10 daysC
Imaging comparable to TEE in detection of vegetations and possibly superior in defining paravalvulaar infection
Cardiac CT angiogram (CTA)
Drug of choice for streptococci endocarditis
Penicillin + Gentamicin regimen (duration depends on sensitivity)
Preferred duration of treatment for PVE
6 weeks
Used in streptococci IE for patients with immediate (urticarial) severe penicillin allergy
Vancomycin
Dose of gentamicin for Streptococcal IE
Gentamicin 3mg/kg daily IV or IM as a single dose or divided into equal doses
Duration:
2 weeks if penicillin susceptible and relatively penicillin-resistant
6 weeks if moderately penicillin-resistant strep
Preferred cell wall-active agent for use in combination with gentamicin for Enterococci IE
Ampicillin or penicillin
Regimen:
Penicillin G (4–5 mU IV q4h) plus gentamicin (1 mg/ kg IV q8h), both for 4–6 weeks
Ampicillin (2 g IV q4h) plus gentamicind (1 mg/kg IV q8h), both for 4–6 weeks
If penicillin allergic or isolates are resistant to penicillin/ampicillin: may use Vancomycin
Alternative regimen for E. faecalis (not E. faecium) if strains possess high level gentamicin resistance
Ampicillin-Ceftriaxone
Ampicillin (2 g IV q4h) plus ceftriaxone (2 g IV q12h), both for 6 weeks
Multidrug regimen for MRSA PVE
VAN + Genta (2 weeks only) + Rif
Vancomycin (15 mg/kg IV q12h for 6–8 weeks)
plus
Gentamicin (1 mg/kg IM or IV q8h for 2 weeks)
plus
Rifampin (300 mg PO q8h for 6–8 weeks)
Multidrug regimen for MSSA PVE
Naf/oxa/flucloxa + Genta 2 weeks only) + Rif
Nafcillin, oxacillin, or flucloxacillin (2 g IV q4h for 6–8 weeks)
plus
Gentamicin (1 mg/kg IM or IV q8h for 2 weeks)
plus
Rifampin (300 mg PO q8h for 6–8 weeks)
Regimen for MRSA NVE
Vancomycin (15 mg/kg IV q8–12h) or daptomycin (8–10 mg/kg daily) for 6 weeks
Drug of choice for febrile patients in whom prolonged neutropenia (>7 days) is anticipated
(1) ceftazidime or cefepime
(2) piperacillin/tazobactam
(3) imipenem/cilastatin or meropenem
When to initiate and stop G-CSF / GM-CSF
Start 24-72h after chemotherapy
Continue until ANC is 10,000 /uL
Do not use concurrently with chemo or radiation therapy
Fever of unknown origin work up (required)
TB: tuberculin skin test (TST) or interferon γ release assay (IGRA)
Inflammation: ESR, CRP, LDH, Ferritin
Hema: CBC: platelet count; leukocyte count and differential; hemoglobin, protein electrophoresis
Immunologic: antinuclear antibodies, and rheumatoid factor
GI: Alkaline phosphatase, ALT, AST
Renal: Electrolytes, creatinine, total protein, urinalysis, creatine kinase
Cultures: Blood cultures (n = 3)
Urine culture
Imaging: chest x-ray, Abdominal ultrasonography
Most common among the neoplasms that present with FUO
Malignant lymphoma
Next work up in FUO after obligatory investigations, manipulation with thermometer and drug fever excluded, and still with misleading or absent PDCs
Cryogobulin and fundoscopy
> FDG-PET/CT or gallium scan/labeled leukocyte scintigraphy
If normal, repeat history and PE and PDC driven invasive testing
If still no diagnosis, late state work up is chest CT and abdominal CT, temporal artery biopsy >55y
Tx if still with no dx for FUO after chest and abdominal CT and temporal artery biopsy
Stable: follow up and consider NSAID tx
Deterioration: further tests and consider therapeutic trial with Anakinra
Condition that may increase the risk of an adverse event or that may compromise the ability of the vaccine to evoke immunity
Precaution
Condition that increases the risk of a serious adverse reaction to vaccination
Contraindication
Permanent contraindications to vaccination
Severe allergic reaction to a vaccine component or following a prior dose
Encephalopathy not due to another identifiable cause occurring within 7 days of pertussis vaccination
Gold standard for a diagnosis of HIV infection
positive EIA with a positive HIV RNA assay
In cases with strong clinical evidence of leptospirosis, a SINGLE antibody titer (MAT) __ is required for diagnosis
1:200-1:800
Treatment for severe leptospirosis (4)
Penicillin (1.5 million units IV or IM q6h) or
Ceftriaxone (2 g/d IV) or
Cefotaxime (1 g IV q6h) or
Doxycycline (loading dose of 200 mg IV, then 100 mg IV q12h)
Chemoprophylaxis for Leptospirosis
Doxycycline (200 mg PO once a week) or Azithromycin (250 mg PO once or twice a week)
- Doxy contraindicated if pregnant
Tx for mild leptospirosis (3)
Doxycycline (100 mg PO bid) or Amoxicillin (500 mg PO tid) or Ampicillin (500 mg PO tid)
First line treatment for uncomplicated P. falciparum malaria in malaria endemic areas
Artemisin-based combination therapy (ACT)
Prophylaxis in areas with chloroquine- or mefloquine- resistant P. falciparum
Atovaquone-proguanil (Malarone)
Doxycycline
Only drug advised for pregnant women traveling to areas with drug-resistant malaria
Mefloquine
Timing of antimalarial drugs
Start 2 days to 2 weeks before departure
Continue for 4 weeks after the traveler has left the endemic area
If atovaquone-proguanil was given- can d/c after 1 week
Added to regimen tovprevent relapse incap. vivax or P. ovale infection
Primaquine
Rabies spreads ____ along peripheral nerves toward the spinal cord or brainstem via retrograde fast axonal transport (rate, up to ~250 mm/d), with delays at intervals of ~12 h at each synapse
CENTRIPETALLY
Eosinophilic cytoplasmic inclusions in brain neurons that are composed of rabies virus proteins and viral RNA
Negri bodies
Rabies PRE exposure prophylaxis schedule
Day 0, 7, 21 OR 28
Rabies Post exposure prophylaxis schedule
Day 0, 3, 7, 14, 28
Rabies category of “minor or superficial scratches or abrasions without bleeding, including those induced to bleed”
Ctagory 2
But all cat 2 on head and neck are considered cat 3
Management of Cat 2 rabies
Wash with soap and water
No RIG indicated
Complete vaccination until Day 28 if
-animal is laboratory proven to be rabid
-animal is killed without lab testing
-animal has signs and sx of rabies
-animal is not available to be observed for 14 days
Site of administration of RIG
Entire dose of RIG (20IU/kg) should be infiltrated at the site of the bite
T/N: rabies vaccine and RIG should never be administered at the same site or with the same syringe
Preferred antibiotic therapy for tetanus
Metronidazole 400mg rectally or 500mg IV q6h for 7 days
Treatment of tetanus
Antitoxib should be given early (HUMAN tetanus Ig or equine antitoxin)
Tetanus toxoid in pregnancy… how many doses
All pregnant women should received at least TWO doses tetanus toxoid containing vaccine with interval of at least 4 weeks between doses and second dose at least 2 weeks before birth
3rd dose should be given 6 months after the 2nd dose
4th and 5th doses should be given with interval of at least 1 year or in subsequent pregnancies (to complete 5 doses) to ensure lifelong protection
Most common site of infectious arthritis in IV drug users
spine, sacroiliac joints, sternoclacivular joints
Antibiotics added in case of IV drug users for coverage of PAE infectious arthritis
Cefepime 2g q8h-12h or
Ceftazidime 2g q8h
Primary treatment for gas gangrene
Clindamycin + Pen G
Clindamycin (600–900 mg IV q6–8h) plus penicillin G (4 million units IV q4–6h)
alternative: Clinda+cefoxitin 2 grams IV q6h
Primary treatment for necrotizing fasciitis (Group A strep)
Clindamycin + Pen G
Clindamycin (600–900 mg IV q6–8h) plus penicillin G (4 million units IV q4–6h)
alternative:Clinda+1st or 2nd gen ceph
Primary treatment for necrotizing fasciitis (mixed aerobes and anaerobes)
Ampicillin + Clindamycin + Ciprofloxacin
Ampicillin (2 g IV q4h) plus clindamycin (600–900 mg IV q6–8h) plus ciprofloxacin (400 mg IV q6–8h)
alternative: VAN + Metro + Ciprofloxacin
Usual cause of traumatic gangrene (from penetrating injuries)
Clostridium species
C. perfringens, C. septicum, C. histolyticum
Lucio’s phenomenon
Leprosy reaction, observed in diffuse leprosy of Lucio and Latapi and may be a variant of erythema nodosum
Marked vasculitis and thrombosis of the superficial and deep vessels result in hemorrhage and infarction of the skin
3 cardinal signs for diagnosis of leprosy (need 2 of 3 for dx)
Hypopigmented or erythematous skin lesions with definite loss or impairment of sensation
Involvement of the peripheral nerves as demonstrated by definite thickening with sensory impairment
Positive result for AFB in slit-skin smears / biopsy sample / positive result in a biopsy PCR v
Treatment for T1R leprosy reaction
Glucocorticoids
Prednisolone 1mg/kg body weight once a day (max 60-80mg) tapered slowly
Treatment for multibacillary leprosy (adult)
Dapsone 100mg daily
Rifampin 600mg monthly
Clofazimine 50mg daily, 300mg monthly
*supervised 4-weekly dose of rifampin and clofazimine
for 12 months
(6 months for paucibacillary)
Syndrome of fever, myalgia, general malaise, fatigue, headache, nonproductive cough, abdominal symptoms in a patient who contracted schistosomiasis
Katayama fever / Katayama syndrome
Preemptive treatment for px at risk for invasive NTS infection considered for:
neonates (probably up to 3 months of age); persons >50 years of age with known or suspected atherosclerosis; and patients with immunosuppression, cardiac valvular or endovascular abnormalities, or significant joint disease
UTI: Definition of significant pyuria
> 10 WBC/HPF
UTI: Definition of positive gram stain of unspun urine
> 2microorganism/oif
Asymptomatic bacteriuria cut off
Women: 2 consecutive voided urine with same bacterial strain >100,000 cfu/mL
Men: clean-catch voided urine with same bacterial strain >100,000 cfu/mL
If catheterized: 100cfu/mL
Definition of recurrent UTI
3 or more AUC in a year or
2 or more in 6 months
*documented by urine culture
Relapse if it occurs 1-2 weeks after stopping tx
Reinfection if >2 weeks
Cut off value for significant bacteriuria in complicated UTI
100,000 cfu/mL
Treatment duration in complicated UTI
at least 7-14 days
Repeat urine culture 1-2 weeks after completion of antibiotics
Cut off value for bacteriuria in CA-UTI
10^3 aka 1,000 cfu/mL in a single catheter urine specimen or in a midstream voided urine specimen
