Streptococcus pneumoniae: Difference between revisions

Revision as of 00:32, 3 October 2019

Gram-positive, lancet-shaped diplococci
90+ serotypes, based on capsular polysaccharide that is bound to peptidoglycan
Lab identification is based on α-hemolysis of blood agar (from pneumolysin), optochin susceptibility, and bile salt solubility

Present worldwide
Major cause of morbidity and mortality in children
- Leading cause of under-5 mortality worldwide

Acquired by coughing and sneezing
Asymptomatic carriage or colonization in the nasopharynx
Invasion through epithelial cells into the bloodstream, using the PAF and pIg receptors
Capsule and various proteins help it to evade immune system

4-10% in the general adult population, usually lasting several weeks
Highest in children, up to 30-60% depending on the situation, lasting up to 6 months

Acute onset of cough (92%), fatigue (63%), shortness of breath (47%), and dyspnea (23%) with documented or subjective fever (92%), chills (77%), sweats, purulent sputum, and pleuritic chest pain (79%)

Most common cause of meningitis in adults
Acquired by hematogenous spread from nasopharynx, or direct invasion from sinuses
May be secondary to otitis media or sinusitis
CSF leaks and other defects predispose to infection
Diagnostic yield in CSF decrease significantly 4 hours after administration of antibiotics

@@ Line 17: / Line 17: @@
 * Invasion through epithelial cells into the bloodstream, using the PAF and pIg receptors
 * Capsule and various proteins help it to evade immune system
+== Clinical Presentation ==
+=== Asymptomatic carriage ===
+* 4-10% in the general adult population, usually lasting several weeks
+* Highest in children, up to 30-60% depending on the situation, lasting up to 6 months
+=== Otitis media ===
+=== Sinusitis ===
+=== Bacteremia ===
+=== Pneumonia ===
+* Acute onset of cough (92%), fatigue (63%), shortness of breath (47%), and dyspnea (23%) with documented or subjective fever (92%), chills (77%), sweats, purulent sputum, and pleuritic chest pain (79%)
+=== Meningitis ===
+* Most common cause of meningitis in adults
+* Acquired by hematogenous spread from nasopharynx, or direct invasion from sinuses
+* May be secondary to otitis media or sinusitis
+* CSF leaks and other defects predispose to infection
+* Diagnostic yield in CSF decrease significantly 4 hours after administration of antibiotics
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