Infectious Flashcards
Tuberculosis cause
mycobacterium tuberculosis; inhaled aerosol droplets via coughing; primary, active/progressive primary, latent phases
Tuberculosis s/s
cough (dry -> progressive) >3 weeks with or without hemoptysis; fever, drenching night sweats, anorexia, weight loss; pleuritic chest pain, dyspnea, hemoptysis, post-tussive rales; ill appearing/malnourished
Tuberculosis dx
DNA sputum culture (acid-fast bacilli); biopsy (caseating granulomas); tuberculin skin test/PPD (positive w/ active/latent, induration >15mm); CXR (primary, reactivated, healing primary)
■ Primary CXR: homogeneous infiltrates, hilar/paratracheal lymph node enlargement, segmental atelectasis, cavitations w/ progressive disease
■ Reactivation CXR: fibrocavitary apical disease, nodules, infiltrates, posterior and apical segments of the right upper lobe, apical-posterior segments of left upper lobe, superior segments of the lower lobe
■ Healed Primary CXR: Ghon complexes (calcifications), Ranke complexes (calcifications w/ hilar lymph nodes)
Tuberculosis tx
Isoniazid (INH), Rifampin (RIF), Pyrazinamide (PZA), Ethambutol (EMB); BCG vaccine (high risk)
■ LTBI: INH x9mos or RIFx4mos or RIF + PZA x2mos
■ Active TB: INH + RIF + PZA + EMB x2mos
■ ADEs: INH (give pyridoxine for neuropathy, hepatitis), RIF (orange fluid), EMB (optic neuritis)
Atypical Mycobacterial Disease cause
mycobacterium marinum, mycobacterium avium-intracellulare; contaminated water, injections, surgical procedures, trauma, cockroaches, immunosuppression (emphysema, DM, leukemia, lung cancer, CKD, SLE)
Atypical Mycobacterial Disease s/s
lymphadenitis, multiple/isolated skin nodules in linear distribution; pulmonary consolidation, cavitation, fibrosis, nodules, bronchiectasis, adenopathy
Atypical Mycobacterial Disease dx
tissue culture; electrophoresis, polymerase chain, CXR (centrilobular nodules isolated in lingual and middle lobe)
Atypical Mycobacterial Disease tx
antibiotics (clarithromycin); surgical drainage/debridement/prolonged treatment w/ antimicrobial agents
Human Immunodeficiency Virus cause
retrovirus integrating into DNA, attacking CD4 T-cells (helper T cells); sexual transmission, IV drug use, occupational injury, blood products, mom-to-baby
Human Immunodeficiency Virus s/s
mono-like/flu-like illness for 2 weeks, rash, mucocutaneous ulcers, myalgias, fever, sore throat, adenopathy, N/V/D, HA (early HIV); asymptomatic, LAD lasts 10 years (clinical latency); LAD, tissue damage, fever, night sweats, weight loss, oral hairy leukoplakia, thrush, skin disorders (molluscum) (symptomatic infection)
Human Immunodeficiency Virus dx
HIV positive antigen/antibody testing, CBC, CMP, toxoplasma IgG, Hep A/B/C, RPR, STDs, PPD, pap (initial screen); Viral load >100K, elevated LFTs, leukopenia, anemia, thrombocytopenia (early); Viral load decreases to “set point” then rises, CD4 count declines (clinical latency); Viral load increase, CD4 count decreases (symptomatic infection); CD4 <200 or HIV + AND 1/27 AIDS defining conditions (PCP pneumonia, toxoplasmosis, mycobacterium avium complex, CMV, candidiasis, Kaposi’s sarcoma, cervical cancer, etc);
Human Immunodeficiency Virus tx
viral load <50 then treat opportunistic infections; antiretroviral therapy (3 drugs from 2 classes; NNRTIs, NRTIs, PIs, integrase inhibitor, fusion inhibitors); non-occupational HIV exposure (begin <72hrs); occupational exposure (being w/in hrs, treat x4wks)
Pneumocystis Jiroveci Pneumonia (PCP) cause
pneumocystis jiroveci (fungi)
Pneumocystis Jiroveci Pneumonia (PCP) s/s
fever, cough, SOB; severe hypoxemia
Pneumocystis Jiroveci Pneumonia (PCP) dx
sputum sample culture, elevated LDH; CXR (diffuse perihilar infiltrates); CD4 <200
Pneumocystis Jiroveci Pneumonia (PCP) tx
Bactrim DS, supportive
Toxoplasmosis cause
encephalitis by toxoplasma gondii; ingestion of cat feces, raw foods
Toxoplasmosis s/s
HA, focal neurological deficits, seizures, AMS, retinitis, pneumonitis
Toxoplasmosis dx
CT/MRI (multiple contrast-enhancing lesions), seropositive for toxoplasmosis; CD4 <100
Toxoplasmosis tx
Bactrim DS
Mycobacterium Avium Complex cause
mycobacterium avium, mycobacterium intracellulare; found in soil and inhaled/ingested dust
Mycobacterium Avium Complex s/s
night sweats, weight loss, abdominal pain, diarrhea, anemia, pulmonary infection
Mycobacterium Avium Complex dx
sputum culture (acid-fast bacillus); positive blood cultures; CD4 <50
Mycobacterium Avium Complex tx
Zithromax (azithromycin), clarithromycin
Cytomegalovirus retinitis cause
CMV, herpes virus; blood, sexually transmitted, perinatally
Cytomegalovirus retinitis s/s
visual disturbances, blindness
Cytomegalovirus retinitis dx
perivascular hemorrhages, white fluffy exudates (cotton wool spots) on fundoscopic exam; seropositive for CMV
Esophageal Candidiasis/Recurrent Vaginal Candidiasis cause
candida albicans
Esophageal Candidiasis/Recurrent Vaginal Candidiasis s/s
white cottage cheese-like patches on esophagus or in vaginal canal; more invasive candidiasis, lower CD4 count
Esophageal Candidiasis/Recurrent Vaginal Candidiasis dx
clinical; endoscopy; CD4 count low
Esophageal Candidiasis/Recurrent Vaginal Candidiasis tx
Diflucan
Kaposi’s Sarcoma cause
vascular neoplasm; homosexual transmission
Kaposi’s Sarcoma s/s
multifocal/widespread lesions, LAD
Kaposi’s Sarcoma dx
clinical; CD4 count low
Hepatitis cause
viral (A, B, C, D, E); alcohol, acetaminophen, drugs; Wilson’s disease, a-antitrypsin deficiency; autoimmune
■ Hep A, E: fecal oral transmission
■ Hep B, C, D: parenterally or mucous contracted
Hepatitis s/s
fatigue, malaise, anorexia, tea colored urine, abdominal discomfort, scleral icterus, jaundice
Hepatitis dx
liver biopsy; aminotransferase elevations, bilirubin >3, antibody/antigen testing
■ Acute Hep A (anti-HAV)
■ Hep B infection (HBsAg), past infection/immunity (HBsAb), acute infection (HBcAg), highly infectious (HBeAg), low titer (HBcAb), high DNA load
■ Chronic infection (ALT, AST, increase, hepatocellular damage on biopsy)
Hepatitis tx
supportive (avoid alcohol, meds, toxins); adenofovir, lamivudine (Hep B); pegylated inferno a2 + ribavirin (Hep C); vaccinate against Hep A,B
Influenza cause
orthomyxovirus; mucous droplets
Influenza s/s
abrupt, fever, chills, malaise, muscle aches, substernal chest pain, headache, nasal stiffness, nausea (onset 18-72hrs after infection); fever (1-7 days), coryza, nonproductive cough, photophobia, eye pain, sore throat, pharyngeal injection, flushed facies, wheezes, rhonchi; pneumonia, Reye syndrome (fatty liver w/ encephalopathy)
Influenza dx
viral cultures vs rapid flu; CXR (bilateral diffuse infiltrates); leukopenia, proteinuria
Influenza tx
supportive (rest, analgesics, cough suppressants); oseltamivir (Tamiflu); fluids; vaccine
Varicella-Zoster (Shingles) cause
Varicella-zoster virus (herpes family)
Varicella-Zoster (Shingles) s/s
abrupt painful, erythematous macules and papules lesions (dew drops on rose petal) with a crust in a centripetal pattern on the dermatome; low grade fever, malaise, muscle aches, arthralgias, headache; Hutchinson sign (tip of nose and trigeminal pattern)
Varicella-Zoster (Shingles) dx
clinically; fluorescent microscopy
Varicella-Zoster (Shingles) tx
supportive (pain medication, acyclovir); Varicella-zoster immunoglobulin (immunocompromised); Zostavax vaccine
