Infectious disease

• aka acquired hypogammaglobulinemia
• suspected in patients with recurrent gastrointestinal infections (especially giardiasis) and respiratory infections
• Dx: decreased serum IgG levels
• Sx: malabsorption, small bowel bacterial overgrowth
• Risks: autoimmune or neoplastic diesase

• malodorous discharge w/o irritation or pain
• homogeneous, white discharge, without vaginal erythema
• Clue cells: squamous epithelial cells with obscured edges
• vaginal pH >4.5
• fishy odor either before or after addition of 10% potassium hydroxide
• Tx: metronidazole or clindamycin (orally or vaginally)

• "cottage cheese-like" vaginal discharge
• moderate to significatn vaginal irritation, inflammation
• lack of odor
• high pH
• stained specimens show pseudohyphae and budding yeast

• yellow-green discharge
• pruritic
• "frothy" discharge
• high pH

• Abx can cause or prolong fever
• Common cause: beta-lactam antibiotics
• Eosinophilia and rash accompany drug fever in 25% of cases

• 2 or more of the following:
• temp > 100.4
• HR > 90
• RR > 20 (or  Pco2 <32)
• leukocyte count >12 or <4 or >10% band forms

SIRS + confirmed infectious process

Sepsis with organ dysfunction, hypoperfusion, or hypotesion

Sepsis-induced hypotension or hypoperfusion abnormalities despite adequate fluid resuscitation

Aggressive fluid resuscitation with resolution of lactic acidosis within 6 hours

• Zanamivir (relenza) or oseltamivir (tamiflu)
• trivalent, inactivated influenza vaccine (intramuscular)

• neuraminidase inhibitor
• treats influenza A and B

• neurominidase inhibitor
• treats influenza A and B
• inhaled, associated with bronchospasm in 5 to 10% of patients with asthma

• only active against influenza A
• >90% of circulating influenza A virus were resistant to amantadine and rimantadine

• rhinitis medicamentosa
• persistent rhinitis symptoms in setting of chronic use
• tx: withdrawal vasoconstrictor and initiate treatment with nasal corticosteroid spray

• duration of symptoms >1 week
• worsening after initial improvement
• maxillary tenderness
• purulent drainage
• poor response to decongestants

• Streptococcus pneumoniae
• Haemophilus influenca
• Tx: 3- to 10-day course of narrow-spectrum antibiotics (amoxicillin, TMP-SMZ, doxycycline)

• most caused by viral infection
• tx: symptomatic
• Sx: URI > 7 days, facial pain, purulent nasal discharge (1 of 3 fives <25% probability of bacterial sinusitis)
• 2-3 of these sx, antibiotic therapy may be warranted

• UTI ± flank pain ± fever ± naus/vom
• Tx: oral (when appropriate)
• Empiric tx: oral levofloxacin x 7 days (some say 7 to 14 days)
• alternatives: 3rd gen cephalosporin, extended-spectrum penicillins or aminoglycosides, monobactams, carbapenems

• Tx: 3-day course of trimethoprim-sulfamethoxazole
• must do pregnancy test first
• ciprofloxacin if unrelieved dysuria and bacteriuria after TMP-SMZ

• painful vesicles progressing to pustules and then to ulcers or erosions
• tender inguinal LAD
• incubation period: 3 to 5 days
• Tx: oral valacyclovir

• ester of acyclovir
• converted to acyclovir in the liver
• better absorption, higher drug levels than oral acyclovir

• generalized rash (palms and soles, included)
• low grade fever
• generalized LAD
• Dx: RPR test (screen)

• associated with HIV infection and odynophagia
• tx: fluconazole
• may need upper endoscopy (esophageal candidiasis)

• not detectable until about 6 weeks after infection
• test HIV viral load

• Initiate ART for treatment-naive patient when CD4 count <200
• Regimen: three or more agents (i.e., zidovudine, didanosine, nelfinavir)

progressive multifocal leukoencephalopathy

• opportunistic infection caused by polyomavirus JC
• Demyelination of the central nervous system that causes gradually progressive neurologic deficits
• Radiograph: no mass effect
• Approx 50% of pts with AIDS and PML will survive the latter disease if they start HAART

Chlorhexidine is superior skin cleanser and has residual activity for at least 30 minutes

• remove whenever possible
• 90% of UTIs are related to indwelling catheters

• risk factors: chest trauma, low glasgow coma scale, need for mechanical ventilators
• Prevention: keep bed at 45-degree angle, maintain gastric acidity, maximizing nutrition, preventing colonization or cross-contamination
• Equipment needs to be changed every 2 weeks in adults

• nosocomial, health-care acquired pneumonia
• must cover for resistant organisms including MRSA/pseudomonas
• risk: prior hospitalization within 90 days
• Initial tx: (broad spectrum) vancomycin, cefepime, ciprofloxacin

• anti-tumor necrosis factor-α
• increases risk for reactivation of tuberculosis, often extrapulmonic disease

sx: fever, dypsnea, diffuse pulmonary infiltrates

• 1. isoniazid, rifampin, pyrazinamide
• 2. isoniazid, rifampin, pyrazinamide, ethambutol
• 3. isoniazid, rifampin, pyrazinamide, streptomycin

• isonizid for 9 months
• 88% reduction of reactivation tuberculosis in the first year, 68% reduction over the next 10 years

BCG vaccination does NOT change the interpretation of TB skin test in most adults

• immunosuppressed patients have an increased risk for developing primary or reactivation tuberculosis
• PPD testing before starting dose of prednisone

• anaerobic organisms (often from the mouth)
• coverage: clindamycin
• Risk factors: difficulty swallowing, episodes of depressed consciousness, mechanical factors (esophageal obstruction)

• empiric therapy for ward:
• 1. IV fluoroquinolone alone (i.e. ceftriaxone)
• 2. IV beta-lactam + IV/oral macrolide or doxycycline

• Empiric tx for ICU:
• 1. IV beta-lactam (ceftriaxone or cefotaxime) + IV macrolide (azithromycin) or IV fluoroquinolone

Risk for pseudomonas: anti-pseudomonal beta-lactam

• improvement in fever, cough, dyspnea
• decrease in the leukocyte count
• Most patients, oral therapy can be instituted within 3 days
• do NOT need to wait for change in radiograph findings

• Tx: azithromycin, or clarithromycin (advanced-generation macrolides) or doxycycline
• pathogens: streptococcus pneumoniae, atypical organisms (mycoplama pneumoniae, chlamydophila pneumoniae, legionella pneumophila)
• Empiric treatment without waiting for gram-stain or cultures

• cutaneous lesions: asymptomatic
• cause is human herpesvirus 8

• Tx: amoxicillin-clavulanate (Augmentin)
• polymicrobial: cover for GP, GN, anaerobes
• Augmentin is also used for dog bites

• effective against GP and anaerobes
• treatment of lung abscesses and female genital tract

• treatment of choice for legionnaire disease
• outpatient treatment of CAP

• invasive aspergillosis: occurs in immunocompromised patients
• disease: fever, cough, dyspnea, hemoptysis
• CXR: cavitary lesion
• CT: halo sign or lesions with an air crescent

viridans group streptococci

• Staphylococcus aureus 
• IV drug users
• tricuspid valve involvement > aortic valve
• increasing with inspiration: tricuspid involvement
• Tx: iv vancomycin (emperic)

• caused by fungus Rhizopus
• Presentation: diabetics, fever, dull facial pain, bloody nasal discharge
• diplopia, headache
• Tx: surgical debridement + IV amphotericin

• Echinococcosis
• tapeworm echinococcus
• Source: sheep

• echinococcus
• liver, lungs
• hydatid cyst

neurocysticercosis

• Haemophilus aphrophilus
• Aggregatibacter actinomycetemcomitans
• Cardiobacterium
• Eikenella: GN anaerobe, human oral flora
• Kingella
• 3% of infective endocarditis

• colonoscopy
• GI malignancy

• Vibrio parahaemolyticus
• diarrhea, bloody, mucus
• incubation: 4hr - 4days

• dysentery
• daycare centers or institutional settings

• colitis
• transmission: improperly cooked ground beef

yersiniosis

• peripheral neuropathy, numbness, ataxia
• Tx: pyridoxine increased to 100mg/day
• other side effect: hepatitis

• Mycobacterium tuberculosis
• atypical mycobacteria
• Nocardia
• GNRs
• anaerobes

• GP, weakly acid-fast, filamentous branching rod
• found in soil and water
• Primarily involve lungs
• Tx: trimethoprim-sulfamethoxazole

• CD4 <100/microL
• fever, weight loss, night sweats, n/v, cough with SOB
• HSM
• Dx: urine antigens
• Tx: itraconazole

• Bartonella, GN bacillus
• Tx: oral erythromycin

• Start azithromycin for mycobacterium avium complex MAC
• azithromycin or clarithromycin

• early stage: erythema migrans, fatigue, malaise lethargy, myalgias, arthralgias
• Early disseminated: carditis, neurologic, muscular, conjunctivitis, skin
• Late or chronic: muscular, neurologic
• Cause: borrelia burgdorferi
• Tx: doxycycline

• most common: staphylococcus aureus
• nail puncture: pseudomonas aeruginosa

• increase risk of infection with listeria monocytogenes 
• Iron overload also a risk for yersinia enterocolitica and septicemia from vibrio vulnificus

• fever, dry cough, exertional dyspnea
• CD4 <200
• Tx: trimethoprim-sulfamethoxazole
• Prednisolone in combination when PaO2 is <70

• erythematous and maculopapular rash
• starts on face, progresses to trunk and extremities
• fever, lymphadenopathy, malaise
• mild coryza and conjunctivitis

pseudomonas aeruginosa

• high-risk cardiac conditions: prosthetic valves, previoius bacterial endocarditis, complex cyanotic congenital heart diseases
• Moderate risk: most congenital cardiac malformations, acquired valve dysfunction, hypertrophic cardiomyopathy, mitral valve prolapse
• Ppx: amoxacillin 2G PO 1hr prior; or amp 2G IV 30min prior

• staphylococci, streptococci, salmonella species
• Tx: vancomycin plus ceftriaxone