Infectious Diseases Flashcards
Triad of typhoid fever
Step-wise fever, rose spots and relative bradycardia
Time to development of C.dif post antivioic exposure
Upto 6 weeks
3 treatment regimens for LTBI
Rifapentine + INH x 12 weeks
INH alone for 6-9 months
Rifampin x 4 months
Classification of C.diff colitis
Non-severe
Severe: Cr >1.5 or WBC >15000
Fulminant: ileus, megacolon or hypotension
Hypoalbuminemia in c.diff
Protein losing inflammatory enteropathy
Causative agents of viral meningitis in children
Enterovirus (coxsackie)
HSV
Arbovirus (west nile)
Treatment of RMSF
Doxycycline
CD4 count for PCP
200
CD4 count for cryptococcal meningitis
100
Treatment of PCP
TMP-SMX + Steroids
Triage for influenza with high risk features
ED evaluation
Rx o acute bacterial sinusitis
Amoxi-clav (1st line)
FQs and doxy (2nd line)
Diagnostic criteria for acute bacterial sinusitis
Persistent symptoms for >10 days
Purulent nasal discharge or facial pain >3 days
Worsening of symptoms after resolution of viral URI >5 days
Age for HPV vaccine in males and females
Female 26 and male 21
8 criteria for Hep B vaccination
- High risk sexual practices or personal history of STD
- MSM
- IVDU
- H/O CKD, HIV or Hep C
- Household contacts of patients with chronic HBV
- All pregnant females
- HCW
- Incarcerated facilities
Mode of HBV transmission in endemic areas and low prevalence countries
Endemic - Vertical transmission
Low prevalence regions - IVDU and sexual transmission
Most common cause of viral diarrhea
Norovirus
Difference between erysipelas and cellulitis
Erysipelas - sharp demarcation between normal and involved skin
Cellulitis - poorly defined margins
What is diaper impetigo
Diaper rash -> Infected by stool and urine -> Staph and strep infection -> Erythematous papules and pustules with honey crusted lesions
Signs of sepsis in diaper impetigo
Irritable and crying child
Rx of diaper impetigo not complicated by sepsis
Oral cephalexin and mupirocin ointment
Rx of diaper impetigo with sepsis
Parenteral antibiotics
Types of diaper rashes
Candida rash
Impetigo
Strep dermatitis
HSV
Diagnostic test for west nile encephalitis
CSF West nile IGM positive
Test for C.diff
Stool EIA and GDH
Stool NAAT
Causes of non-inflammatory diarrhea
Viral: Norovirus and rotavirus
Bacteria: ETEC, Vibrio,
Parasites: Giardia, cryptosporidium and cryptococcus
Intestinal tape-worms
Approach to diarrhea
Vomiting predominant vs diarrhea predominant
Inflammatory vs on-inflammatory
Invasive/blood diarrhea
Stool leukocytes and RBC in non-inflammatory diarrhea
Negative
Causes of inflammatory diarrhea
Salmonella, shigella, yersinia, STEC
Pustules with central umblication
Molluscum contagiosum
Cryptococcus
Cutaneous cryptococcosis
Preferentially affects head and neck
Sign of disseminated infection
What is pyoderma gangrenosum
Occus in IBD and inflammatory arthritis
Purple papule that degenerate into ulcers
Dx of cutaneous cryptococcus
Skin biopsy
Rx of cutaneous cryptococcus
2 weeks of AMP B + Flucytosine —> 1 year of Fluconazole oral
Rx of trichomonas vaginitis
Rx patient and partner with oral metronidazole
Strawberry cervix Dx
Trichomonas vaginitis
Trichomonas vaginitis increases the risk of which STD
HIV
Fever with relative bradycardia DDx
Typhoid and legionella
Rx of legionella
Respiratory FQs and newer macrolides
Triad of clinical symptoms in legionella
Neurological: Confusion and ataxia
Pulmonary: Bilateral unilobar or interstitial pneumonia
GI: Diarrhea
Metabolic abnormalities in legionella
Hepatic dysfunction and hyponatremia
Which antibiotics achieve high intracellular concentration
Azithromycin and levofloxacin
Sputum findings characteristic of legionella
Many WBC with no organisms
Rx of chlamydia
Doxycycline or azithromycin
Rx of chlamydia in pregnancy
Azithromyci
Pregnancy and neonatal complication of chlamydia
Pregnancy: Preterm labor and premature ROM
Neonatal: Conjunctivitis and pneumonia
Non AIDS defining illness in HIV
CVD, CKD, Malignancy
Contraindications for VZV vaccine
- Neomycin allergy
- Gelatin allergy
- Pregnancy
- Immunocompromised state `
What should be monitored if VZV vaccine is administered to houselhold contact of an immunocompromised person
Rash which may be contagious
Rx of asymptomatic bacteriuria and UTI in pregnancy
Fosfomycin
Cephalexin
Amox-clav
Organisms causing UTI in pregnancy
E.Coli, Proteus, and Klebsiella
TMP-SMX fetal complications
1st trimester: NTDs
3rd trimester: Neonatal kernicterus
Suppressive therapy post PN in pregnancy
Low dose nitrofurantoin or cephalexin till 6 weeks post partum
Most common cause of chronic unilateral lymphadenitis in children
Perinauds oculoglandular lymphadenopathy which is a manifeststion of CSD
Characteristic feature of oculo-glandular LN
Unilateral LN + conjunctivitis
Characteristic presentation of Strep throat in children
Exudative tonsillitis without URI symptoms + Tender cervical LN
Rx of strep throat in children
Amoxicillin or cephalosporins in penicillin allergy
Not amoxi-clav
What is HIV associated lipodystrophy
HIV Rx—>
(a) Lipoatrophy —> Skeleton like appearance
(b) Fat accumulation —> buffalo hump and increased abdominal girth
Complications associated with HIV lipodystrophy
Insulin resistance, dyslipidemia, and increased CVD risk
Medication a/w HIV lipoatrophy
Nucleoside reverse transcriptase inhibitor
Criteria for acute liver failure
INR >1.5, encephalopathy, and elevated LFT
Prognosis of acute Hep B infection
Self-limited with rare progression to acute liver failure
Triage of acute Hep B
Outpatient with close follow-up
Indications for hospital admission in acute hep B
- HD instability
2. ALF
Indications for antiviral in acute Hep B
- Immunocompromised
- ALF
- Severe hepatitis
- Concurrent Hep C
Criteria for chronic Hep B
Failure to clear HBsAG after 6 months of acute infection
% of children and adults who develop chronic Hep B after acute Hep B
Children: 10-20%
Adults: 5%`
What is ecthyma gangrenosum?
Chemotherapy patients with indwelling port —> Psuedomonas bacteremia —> bacteria invades adventitia and medial layers of BV wall —> Painless macule followed by bulla formation which ulcerates
DDx of ecthyma gangrenosum
Candidemia skin lesions
Mycosis fungoides
Clostridium myonecrosis
Rx of pseudomonas bacteremia in immunocompromised patient
Pip-Tazo + gentamicin
First step after active TB diagnosis
Drug senstivity testing
Rx of LTBI in close contact
Guided by drug sensitivity results of the contact
Rx of cat scratch disease
Azithromycin
How long should contact sports be avoided after IM diagnosis
3 weeks
Duration of fatigue after IM infection
> 6 months
Airway obstruction after IM
Corticosteroids
Most common causative agents of acute otits media and Rx
Strep pneumo, non typable Hinf, moraxella
Amoxicillin
Recurrence of OM within 1 month after 10 day course of amoxicillin
Beta lactamase producing organisms. Rx with amoxicillin-clavulinic acid
Indications for tympanostomy tube placement for OM
Recurrent OM >3 in 6 month and >4 in a year
Screening test for HIV
4th gen - p24 antigen and HIV antibody
Risk factors for invasive candida infection
Lines
ICU admission
Neutropenia
Sensitivity of induced sputum analysis for PJP
Very poor 50-90%
Indications for steroids in PJP
A-a gradient >35 mm Hg
PaO2 <70
Indications for prophylaxis of meningococci
Close contact
Exposure to respiratory or oral secretions
Seated next to affected individual for >8 hours
Prophylactic antibiotic for meningococcus
Rifampin BID x 2 days —> Interacts with OCPs
Ciprofloxacin 500 one dose
CTX 250 mg 1 dose
Rx of lactational mastitis
Dicloxacillin and cephalexin
Dx of breast abscess
Ultrasound
Induration in lactational mastitis DDx and test
Mastitis and abscess
USG
Rx of chronic bacterial prostatitis
6 weeks of ciprofloxacin
Presentation of chronic bacterial prostatitis
Young middle aged males
>3 months of recurrent UTI, pain in GU area, and/or pain with ejaculation
Rx of huntingtons disease
Tetrabenzine
Neck stiffness DDx
SAH
Only indications for Rx of salmonella
Age <12 months
Immunocompromised individuals
Two types of necrotizing fasciitis
Type 1- DM and PVD —> Polymicrobial
Type 2-No prior Dx—> Group A strep is more common
Crepitus in necrotizing fasciitis
Anaerobes: C perfringens or B fragilis
Absent red reflex
Cataract
Congenital defects in rubella
Cataract, patent ductus arteriosus, SNHL
Skin lesion and neurological abnormality in congenital rubella
Blueberry muffin rash and microcephaly
Rx of sporotrichosis
3-6 months of oral itraconazole
Causes of serum sickness like reaction
Acute Hep B, antibiotics - sulf and beta lactams
Which autoimmune disease does serum sickness resemble and what is the mechanism
Type III hypersensitivity and SLE
Vasculitis associated with acute Hep B
PAN
Causative agent of herpangina
Coxsackie group A
Differentiate between oral vesicular lesions of herpes gingivostaomatitis and herpangina
Gingivostomatitis: Anterior oral mucosa
Herpangina: Posterior mucosa and pharynx
Radiographic features of invasive pulmonary aspergillosis
Halo sign - lung cavity with surrounding ground glass opacities
Air crescent sign - cavity with air fluid levels
Rx of TB in pregnancy
3 drug regimen - all drugs can cross placenta but do not have toxic effects on fetus
TB drug C/I in pregnancy
Pyrazinamide
Duration of antibiotics for strep throat
10 days to prevent ARF
What is HIV associated thrombocytopenia
HIV not on Rx —> low platelets without an apparent cause
Frequency of viral load and CD4 monitoring after ART initiation
3-6 months
Expected decline in viral load post ART initiation
4 weeks: <5000
4 months: <500
6 months: <50
Define virological failure after ART Rx
Viral load >200 after 6 months
Management of VZV
Typical presentation - Oral acyclovir Atypical rash (immunocompromise) - PCR lesion
Rx of Jarisch-Herxheimer reaction
Supportive