Pneumonia, TB, URTI Flashcards
Streptococcus pneumoniae
MOST COMMON CAP Gram + lancet diplococci optochin sensitive alpha hemolytic Quellung rxn: capsule swell IgA protease, lipoteichoic acid disease: pneumonia, meningitis, otitis, sinusitis CXR: LOBAR Dx: Gram stain and culture; rapid urinary antigen test SUDDEN onset, RUSTY sputum POST VIRAL resp. infection Tx: ceftriaxone or penicillin if susceptible, flouroquinolones, azithromycin SEVERE: vancomycin empirically
S. pneumoniae risk factors
alcohol/drugs: aspiration abnormality of respiratory tract or circulatory dynamics splenectomy sickle cell HIV
Pneumovax or polyvalent (23-type) polysaccharide vaccine (PPSV23)
S. pneumo vaccine
65 and older
high risk adults
Prevnar or PCV13
S. Pneumo vaccine
children and infants
high risk adults
mycoplasma pneumoniae
NO cell wall
MOST COMMON atypical pneumonia
CXR: looks worse than patient
military, prison, CHILDREN
ADHESIN binds to ciliated epithelial cells and causes reduced ciliary clearance
Dx: serology, PCR, COLD AGGLUTININS (IgM against O RBC), Eaton agar
NOT gram stain: NO cell wall
Tx: macrolide, flouroquinolone, doxycycline
disease: pneumonia, HEMOLYSIS, rash, CNS, cardiac
Klebsiella pneumoniae
Gram - bacillus ferments lactose incapable of growth at 10 degrees C ALCOHOLICS and MALNOURISHED RED CURRANT JELLY sputum capsule complications: abscess and necrotizing pneumonia Tx: need sus.
pseudomonas aeruginosa
aerobic Gram - bacilli
pyocyanin: blue-green; grape odor
oxidase positive
motile
endotoxin, exotoxin A, elastase, leucocidin, hemolysins, proteases
extensive vasculitis with thrombosis and hemorrhage with necrosis
HCAP/HAP/VAP; CYSTIC FIBROSIS
CXR: diffuse bilateral infiltrates
ventilators (water loving)
Tx: get antibiotic susceptibilities; then cefepime, meropenem or imipenem, ciprofloxacin, pipericillin/tazobactam (best), gentamicin
diseases: pneumonia, wound infection (burn victim), sepsis, external otitis (DM), UTI, hot tub folliculitis
chlamydia pneumoniae
atypical pneumonia
middle age adults (if think it is mycoplasma but older)
Dx: no good test
Tx: doxycycline
Staphylococcus aureus
Gram + cocci in clusters coagulase + catalase + POST VIRAL infection CXR: patchy involving more than one lobe Tx: need susceptibilities complications: necrotizing PNA, lung abscess CAP, HOSPITAL
Haemophilus influenzae
small Gram - coccobacillary rod, pleomorphic, facultative anaerobe
6 serotypes
capsule: type B
culture on chocolate agar requires factors V (NAD+) and X (HEMATIN)
Tx: amoxicillin (mild), ceftriaxone (serious)
disease: pneumonia, EPIGLOTTITIS, otitis media, meningitis, exacerbation of COPD
Acinetobacter baumanii
Gram - coccobacillary rod OPPORTUNISTIC water, soil Hospital, associated with respiratory equipment VAP/HAP, sepsis, line infection, UTI HIGHLY resistant to many antibiotics
legoinella pneumonphila
Gram - rod
ENDOTOXIN, avoid PHAGOLYSOSOME fusion: replicate in macrophages
Dx: urine antigen, CANNOT use gram stain: intracellular (need SILVER stain), charcoal yeast extract with iron and cysteine
hyponatremia, HYPONATREMIA
ventilators: water loving (hotel: air conditioning, showers, sauna)
CXR: consolidation, diffuse interstitial infiltrates, pleural effusion
disease: Legoinnaire’s or Pontiac fever
older and have COMORBIDITIES
Tx: macrolide or flouroquinolone
exotoxin A
PSEUDOMONAS: blocks protein synthesis by inactivating elongation factor EF-2 by ADP ribosylation
Legionnaire’s disease
severe pneumonia with dry cough, fever, diarrhea, confusion
Pontiac fever
mild flu-like symptoms
moraxella catarrhalis
Gram - coccobacillary rods
acute exacerbations of COPD
elderly
disease: pneumonia, sinusitis, otitis media
hospital acquired pneumonia (HAP)
48+ hours after hospital admission
can’t be incubating when you come in
IV catheters, ventilator (highest), immunosuppression, prolonged antibiotic therapy, underlying illness
STAPH and PSEUDOMONAS
healthcare associated pneumonia (HCAP)
- hospitalization of at least 2 days within the prior 90 days
- IV therapy, chemo, wound care in last 30 days
- nursing home resident
- attends hemodialysis clinic or hospital
STAPH and PSEUDOMONAS
influenza virus
Helical, enveloped SS linear -RNA (8 segments)
hemagglutinin, neurominidase, M2
degrades resp. epithelium; necrosis of superficial layers of resp. epithelium
cytokines: myalgia
SUDDEN: fever, sore throat, dry cough, headache, V/D (in children)
Dx: RT-PCR, clinical, direct fluorescent Ab, rapid viral Ag test, viral culture
Tx: oseltamivir, zamanivir
can get SUPERIMPOSED bacterial pneumonia (S. aureus and S. pneumoniae)
prophylaxis: oseltamivir
vaccine: tri or quadvalent (6 mo or older; lasts 6 mo); H3N2
complication: Reye’s
Influenza A
epidemics and pandemics
animals too
subtypes
Influenza B
sporadic outbreaks
no subtypes
humans only
antigenic drift
causes epidemics
spontaneous mutations in the viral genome as it replicates
results in new viral strains different enough to (partially) elude Ab from a previous exposure
antigenic shift
causes pandemics
HA and NA genes are replaced through reassortment with animal influenza viruses
all individuals are susceptible
respiratory syncytial virus (RSV)
pleomorphic, enveloped, ss linear -RNA
S protein (surface spikes)
disease: penumonia, bronchiolitis in INFANTS: cough, wheeze, fever, tachypnea, hypoxemia; URT in adults
outbreaks every winter
Dx: RT PCR on nasal swab, rapid antigen test
CXR: bilateral diffuse infiltrates
Tx: supportive, albuterol, hydration, oxygen; inhaled Ribavirin (stem cell transplant patients)
Prevention: Palvizumab
complication: APNEA, RESP. FAILURE
sequelae: ASTHMA
low mortality
less than 12 weeks, premature, immunosuppressed don’t do well