Bacterial Meningitis

Question 1

classic symptoms of meningitis

Answer 1

headache, fever, stiff neck, photophobia

Question 2

pediactric meningitis symptoms

Answer 2

fever, refusing food, vomiting, fretful, pale blotchy skin, blank stare, drowsy, stiff neck, high pitched cry

Question 3

neisseria meningitidis bacteriology

Answer 3

gram negative diplococci, facultative intracellular. encapsulated. oxidase positive, catalyse positive. ferments glucose and maltose. growth inhibited by fatty acids and metals, needs chocolate agar

Question 4

N. meningitidis pathogenesis

Answer 4

transmitted by airborne droplets. colonise nasopharynx. infection often resolves without symptoms. IgG enhanced complement and neutrophils defend. many people immune by age 20

Question 5

meningococcemia

Answer 5

if N. meningitidis enters bloodstream. colonizes joints, meninges. most common cause in age 2-18 range.

Question 6

meningococci virulence factors

Answer 6

IgA protease: cleaves IgA, reduces defense of mucus membrane. Polysaccharide capsule resists phagocytosis. Endotoxin LOS causes fever and shock.

Question 7

N. meningitidis exam

Answer 7

septic arthritis: joint pain, draw joint fluid. Meningitis: classic fever, headache, stiff neck. young kids show irritability, convulsions, lassitude, fever, vomiting. Draw CSF for both.

Question 8

meningococcemia exam

Answer 8

fever and hourly-spreading petechial skin rash. draw blood and CSF. 5-15% develop waterhouse-friderichen syndrome: fever, shock, purpura, DIC, thrombocytopenia, destruction of adrenal glands

Question 9

N. meningitidis lab

Answer 9

septic arthritis: gram stain and culture on chocolate agar of joint fluid. Meningitis: CSF: increased PMNs, gram stain and culture on choco agar. Gram (-) cocci in CSF smear suffice for diagnosis. Meningococcemia: gram stain and culture blood on choco agar.

Question 10

how to differentiate meningitidis from gonnorrhoeae

Answer 10

only meningococci ferment maltose! can also use immunofluorescence

Question 11

n. meningitidis treatment

Answer 11

penicillin G unless allergic. fulminant meningococcemia: admit to ICU, support circulation and renal function. prescribing glucocorticosteroids for the rash and arthritis is bad!!!!!!!

Question 12

N. meningitidis prevention

Answer 12

close contacts of index case get prophylactic rifampin, ceftriaxone, or ciprofloxacin. vaccines recommended for travelers (mecca, college, etc).

Question 13

group B strep bacteriology

Answer 13

group B strep = S. agalactiae. encapsulated Gram + cocci. beta hemo, polysaccharide toxin virulence factor. pilus like attachment virulence factor. serotype specific antibody mediated immunity. normal vaginal flora. may be normal flora in GI and UR tract

Question 14

GBS pathogenesis in neonates

Answer 14

1-2% of neonates of GBS+ moms develop invasive disease. most common cause of neonatal sepsis. usually serotype 3. early disease: pneumonia w/ bacteremia, presents 1-7 days after birth. prevented by intrapartum IV antibiotics. late disease is bacteremia with meningitis. 1-2 weeks after birth

Question 15

GBS pathogenesis in geriatric group

Answer 15

seen in old people with pre-existing major health conditions. diabetes, malignancy, congestive heart failure. rare infections are more common because of improved reporting and population becoming older and more immunosuppressed

Question 16

GBS exam

Answer 16

pain, fever. meningitis: spinal tap for gram + cocci in pairs or short chains. Cellulitis, abscess: gram stain and culture of appropriate sample. CT/MRI for deep abscesses. echocardiogram for endocarditis

Question 17

GBS lab

Answer 17

CAMP test: CAMP factor secreted by GBS enhances activity of beta hemolysin from staph aureus. Hippurase test: colorimetric test for hippurase, produced by GBS and other bugs

Question 18

GBS treatment

Answer 18

IV penicillin or amoxicillin. if allergic, vancomycin. surgical intervention may be needed.

Question 19

pneumococcus bacteriology

Answer 19

strep pneumoniae. gram +, catalase -, alpha hemo, facultative anaerobe. form diplococci in chains. most common cause of community acquired pneumonia, bacterial meningitis, bacteremia, and otitis media. major childhood pathogen

Question 20

pneumococcus pathogenesis

Answer 20

easily colonizes upper respiratory tract using adhesion virulence factors. in healthy adults and older children, contained by innate immunity. major virulence factor is the capsule. also has IgA protease, and teichoic acid

Question 21

direct extension pneumonia

Answer 21

starts in the throat and spreads without infecting the blood. mainly sticks to sinuses, eustachian tubes, and bronchi

Question 22

hematogenous spread pneumonia

Answer 22

blood, joint fluid, peritoneum, CSF. capsule protects bacteria against phagocytosis and complement unless anti-capsule IgG is already present. pathogenic strains all produce pneumolysin, some also produce hemolysin, neuraminidase, hyaluronidase, but exact contribution of these exotoxins is unclear. infection raises a strong inflammatory response.

Question 23

pneumococcus exam (direct extension)

Answer 23

sinusitis, otitis media, bronchitis, pneumonia. patient looks ill and anxious. predispositions: COPD, asthma, bronchitis, smoking. stethoscope hears rales in most patients, dullness to percussion in half. radiology findings shows lobar consolidation in adolescents and adults. infants and young children have scattered consolidation and bronchopneumonia

Question 24

pneumococcus exam in hematogenous spread

Answer 24

meningitis, septic arthritis, pericarditis, endocarditis, osteomyelitis. bimodal distribution: patients younger than 5 or over 65. meningitis shows mental status changes, lethargy, delirium, brudzinski signs, cranial nerve palsies, focal neurologic defects

Question 25

pneumococcus lab

Answer 25

non invasive disease can be gram stained. invasive disease: gram stain and culture of appropriate samples. begin antibiotic sensitivity testing. urine-antigen testing is available, useful for pneumonia in young children who dont produce enough sputum for testing.

Question 26

meningitis spinal tap findings typical of bacterial meningitis

Answer 26

elevated opening pressure. elevated WBC count and neutrophil level. elevated protein. highly elevated lactic acid. decreased glucose. gram stain and culture are positive unless antibiotic treatment began >4 hours to tap.

Question 27

pneumococcus treatment (non-invasive)

Answer 27

noninvasive: proceed with treatment using antibiotics that include S. pneumoniae among other probable causes: amoxicillin or cephalosporin. fluoroquinolones or doxycycline for adults only. Severe pneumonia: admit, vancomycin.

Question 28

pneumococcus treatment (invasive)

Answer 28

admit, take samples, start antibiotics, start cultures, determine antibiotic resistance. initial antibiotics are vancomycin plus ceftriaxome or cefotaxime. add rifampin, meropenem, or chloramphenicol if resistant ! ! ! !

Question 29

can steroids be used with invasive pneumococcus?

Answer 29

yes! with caution early in the antibiotic course

Question 30

pneumococcus prevention

Answer 30

prevnar7 vaccine raises IgG against capsules of seven serotypes most commonly causing disease prior to 2000. prevnar 13 has original 7 plus 6 more.