Infectious Disease Flashcards
What is malignant otitis externa?
It is osteomyelitis of the skull from pseudomonas in a diabetic patient.
Sxs - brain abscess and destruction of skull
Dx - CT or MRI (initially); Biopsy (most accurate)
Tx - surgical debridement and abx against pseudomonas
What are some of the antibiotics active against pseudomonas?
ciprofloxacin, piperacillin, cefepime, carbapenem, aztreonam
Treatment of gonorrhea?
Ceftriaxone IM
*Safe to use in Pregnant patients
Treatment for Chlamydia?
Azithromycin (single dose);
Doxycycline (for a week);
*Use azithromycin in pregnant patient
“Dogs chase cats”
Diagnostic management for PID?
Best initial test: Pregnancy test, cervical culture and DNA probe(NAAT) for G and C
Most accurate test: Laproscopy
What is the treatment for PID?
Outpatient: IM ceftriaxone and PO doxycycline
Inpatient: IV cefoxitin and doxycycline; may be metronidazole. Cefotetan = cefoxitin
PCN allergy: Clindamycin and gentamycin
Antibiotics that are safe in pregnancy?
Penicillins; Cephalosporins; Aztreonam; Erythromycin; Azithromycin
What is the treatment for HSV?
acyclovir, valacyclovir, famciclovir x 7-10 days
Best initial diagnostic test for Primary syphilis?
Darkfield microscopy
What is Jarisch-Herxheimer rxn?
fever, headache and myalgia developing 24 hours after tx for early stage syphilis. Tx with aspirin
When to desensitize pt with syphilis?
Neurosyphilis and Pregnancy
Alternative Tx for syphilitic patient with PCN allergy?
Doxycycline
Treatment for periodontitis?
Clindamycin or Amox-clav for anaerobic bacteria
What are some distinguishing features of legionella?
contaminated water sources; high grade fever, GI sxs(diarrhea), neurologic sxs (ataxia, confusion)
Dx: hyponatremia, lobar infiltrates on CXR, lots on PMNs no bacteria, urine legionella antigen
Tx with Azithromycin or levofloxacin
dirty wound Tetanus ppx?
If no vaccine in last 10 years or status unknown –> Vaccine and Ig
if vaccine in last 10 years but no booster within last 5 years –> Vaccine only
If vaccine in last 10 years and booster in last 5 years –> no vaccine needed today
clean minor wound tetanus ppx?
If no vaccine in last 10 years or status unknown –> Vaccine only
If vaccine in last 10 years –> no vaccine needed today
clues to histoplasmosis?
erythema nodosum, Pulmonary manifestations, hx of being in a heavily wooded area (ohio and mississippi river valley)
What is the most common regiment for H pylori eradication?
(PPI, Amoxicillin, metronidazole, clarithromycin) or
PPI, bismuth, Metronidazole, tetracycline
how to confirm eradication of h pylori?
carbon 13 urea breath test
diagnosis of h pylori?
EGD; H pylori fecal antigen test; h pylori serology test
what is the treatment for syphilis?
benzathine penicillin G
which test is very sensitive for acid fast bacilli on microscopic examination of sputum smears?
auramine-rhodamine fluorescent stain
what is the first choice patient-applied therapy option for the treatment of anogenital warts?
podophyllotoxin 0.5% solution x 3 days bid topical application; rest period x 4 days; repeated up to 4 times.
When should a PCP patient be give prednisone?
when on ABG shows Po2 <70 mmhg or A-a gradient is 35 or more
how to treat cat bite and what organism is most likely involved?
Pasteurella multocida (gram neg rod); 1st choice is Amoxicillin-clav; if allergic then use doxycylcine
what should be suspected in patient experiencing memory loss, altered personality and behavioural changes, with increased irritability and aggression?
encephalitis
covers anaerobics and aerobics (gram positives) and is drug of choice for lung abscess?
clindamycin
*metronidazole does not cover aerobics
med regimen to treat bacterial meningitis in adult age group?
ceftriaxone+vancomycin+ampicillin
what is the treatment for HSV type 1 encephalitis?
IV acyclovir
Features of RMSV?
triad of fever, headache, myalgia; rash on the palm and soles that becomes hemorrhagic
What ART regimen in the setting of rifampin-based TB treatment is preferred?
Efavirenz plus two NRTIs (emtricitabine + tenofovir)
What is the first line treatment for sever onychomycosis?
oral terbinafine
*oral itraconazole is second line and is contraindicated in pts on statins
MOA and adverse effects of RIPE regimen?
Rifampin (inhibits DNA dependent RNA synthesis; side effect is nausea);
INH (inhibits bacterial cell wall synthesis; side effect is hepatotoxocity and neuropathy); pyrazinamide (inhibits mycolic acid synthesis; side effect is urate underexcretion); ethmabutol (inhibit arabinosyl transferase; side effect is visual problems)
which is the most common complication of EBV infectious mononucleosis?
hepatic complications (elevated liver enzymes)
CSF analysis of viral meningitis?
clear appearance; normal opening pressure; low cell count in contrast to bacterial meningitis; protein is slightly high; glucose is normal; glucose CSF:serum ratio is elevated; Chloride is normal
what is CSF chloride level in TB meningitis?
Low
microorganism in cat bite?
pasteurella multocida
microorganism in cat scratch?
bartonella henselae
antimalaria agent mefloquine would be contraindicated in which patients?
epileptic patients since it has potential neuropsychiatric side effects
how to prevent frequent recurrence of tinea versicolor?
once-monthly topical selenium sulphide or ketoconazole shampoo
What are chemo-prophylactic options for N meningitidis?
Rifampin
Ciprofloxacin
Ceftriaxone
Which vasopressors are indicated when fluid resuscitation does not restore organ perfusion and blood pressure?
Norepinephrine and dopamine;
Norepi is preferred!
What is the treatment for scabies?
topical permethrin and lindane
how to diagnose cryptosporidiosis?
acid fast stain of the stool;
cryptosporidium parvum is the most common cause of chronic diarrhea in HIV-positive patients with CD4 count less than 200 cells/mm3
What distinguishes Legionella from other types of pneumonia?
Hyponatremia
what species can cause mucormycosis?
rhizopus, Mucor, absidia
PCP treatment
oral/IV TMP-SXS; clindamycin and Primaquine; pentamidine
Antifungals are not effective such Amphotericin B and flucytosine
What is Brill-Zinsser disease?
it is a recurrent form of epidemic typhus, caused by infection with Rickettsia prowazekii. it presents abruptly with chills, fever, headache, malaise, and rash on the fourth day.
what is the treatment for HIV-associated lipodystrophy?
Tesamorelin is a growth hormone-releasing factor. it is given daily subcutaneously
What is carditis or neuropathy due to lyme disease treated with?
IV ceftriaxone
what is the treatment of entamoeba histolytica?
metronidazole or tinidazole plus intraluminal antiobiotic (eg paromomycin)
diseases with rashes on palms and soles?
syphilis, RMSF
ehrlichiosis?
tick bite; febrile illness, leukopenia, thrombocytopenia, elevated LFTs; rash is common; “RMSV without spots”; Tx with doxycycline
What is the vaccination protocol in HIV?
no live attenuated vaccines such as varicella, zoster, MMR if CD4 count <200.
all other inactivated vaccine are good to go.
Pneumococcal and HBV are esp recommended in HIV patients
what is time regime for HIV post exposure PPX?
immediately (within 24 hrs) with 2 NRTI (tenofovir and emtricitabine) plus 1 integrase strand transfer inhibitor (eg, raltegrovir) or protease inhibitor or NNRTI x 28 days
what are the malaria chemoprophylaxis options?
chloroquine; in chloroquine resistance areas like India options are Mefloquine, doxycycline, atovaquone-proguanil
How to diagnose Legionella and its Tx?
Urine antigen test and sputum culture on charcoal yeast agar; Tx is fluoroquinolones and macrolides
How to diagnose PCP?
Examination of induced sputum; if this fails then perform bronchoalveolar lavage
What is one of the common adverse effects of vancomycin?
vancomycin flushing syndrome; it is drug induced pseudo-allergic skin reaction; non IgE mediated mast cell degranulation; sxs flushing, erythema, pruritus mainly on face, upper trunk and neck
What is the best medicine for URTI caused by Strep pneumoniae?
Erythromycin; MOA is by binding with 50S ribosomal subunit and thereby inhibiting bacterial protein synthesis
What is the next best step in lyme disease induced bell’s palsy?
Lyme disease serology with ELISA; once confirmed then IV ceftriaxone
What is most effective pharmacological treatment for traveller’s diarrhea?
Azithromycin or a fluroquinolone
CSF analysis of bacterial meningitis is?
High Opening pressure (>180 mm H2O);
WBC (0.01X10^9 - 10X10^9, predominantly PMNs); low Glucose <2.5 mmol/l; high protein >20g/l
What is treatment for uncomplicated pyelonephritis?
outpatient treatment with fluoroquinolones such as ciprofloxacin
What is the treatment for human bites?
amoxicillin/clavulanate;
Ticarcillin/clavulanate; ampicillin/sulbactum
What are the high risk wild animals for rabies?
bats, raccoons, skunks, foxes, coyote
what is coccidioidomycosis?
endemic mold of the dessert Southwest USA (Arizona, california); Sxs include CAP, arthralgia, erythema nodosum or multiforme lasting for weeks or months. Dx with serology and treatment with IV amphotercin B in those with disseminated disease. Otherwise it self resolves in healthy people
What is histoplasmosis?
similar region as blastomycosis i.e midwest USA; mold in soil from bird droppings; sarcoidosis or TB like sxs so be careful not to initiate immunosuppressive therapy; dx with histoplasma urine antigen test. treatment is either self resolve or with antifungal for severe sxs
What is blastomycosis?
similar region as Histoplasmosis i.e midwest USA and great lakes; mold in soil from bird droppings or WOODS; sarcoidosis or TB like sxs so be careful not to initiate immunosuppressive therapy; dx with sputum analysis showing Broad based buddying yeast. treatment is either self resolve or with antifungal for severe sxs
Which Vector transmits chikungunya, dengue, yellow fever, and zika virus?
Aedes mosquitos
Most common causes of encephalitis?
HSV, EBV, Varicella;
Dx with PCR;
Tx with IV acyclovir
Most common causes of infectious esophagitis in HIV patients?
Candidiasis (oral thrush, tx with oral fluconazole)
HSV (endoscopy shows oval/round, volcano-like esophagial lesions; multinucleated giant cells on biopsy; tx with acyclovir/valacyclovir)
CMV (endoscopy shows linear ulcers; intracytoplasmic inclusions on biopsy; tx with IV ganciclovir)
Diagnosis and treatment of pertussis?
Pertussis PCR and treatment with Macrolides
Renal calculi with struvite stones (Magnesium ammonium phosphate); UTI sxs; pH >8;
Proteus mirabilis; urease producing bacteria; urease generates ammonium resulting in urine alkalinization which decreases the solubility of phosphate and increases the risk of renal calculi
filamentous, aerobic, gram positive, partially acid fast bacteria?
Nocardia causes pulmonary or disseminated disease in immunocompromised hosts; treat it with TMP-SMX
Clinically suspected diagnosis meningococcal meningitis?
If clinical suspicion is high, empiric vancomycin and ceftriaxone should be administered as soon as possible; lumbar puncture should not delay the treatment. However, obtain blood cultures before giving antibiotics.
Head CT to r/o intracranial lesions and IV ceftriaxone while waiting for LP, blood cultures
Partially acid fast gram positive aerobic bacteria?
norcardia; contracted via inhalation or skin; causes pneumonia similar to TB (infiltrates and cavitary lesions); abscesses; Diagnose with induced sputum sample or BAL for culture and sensitivity; Gram stain; Tx with TMP-SMX
Tx for cervicofacial actinomyces?
Penicillin
What is the treatment for chlamydia?
Azithromycin 1g PO or Doxycycline 200mg PO BID x 7 days
What is the next best step in female with cervical warts?
refer to specialist clinic for colposcopic exam; biopsy required before treatment
What are anogenital warts also known as?
Condylomata acuminata caused by HPV
