A 41-year-old patient is diagnosed with infective endocarditis. Which of the following has good prognosis?
Correct Answer: Streptococcus viridans
Description: Ans: D (Streptococcus viridans) Ref: Harrison's 18th edn, pg: 1062Explanation:"Overall survival rates for patients with NVE caused by viridans streptococci, HACEK organisms, or enterococci (susceptible to synergistic therapy) are 85-90%. For S. aureus NVE in patients who do not inject drugs, survival rates are 55-70%, whereas 85-90% of injection drug users survive this infection. PVE beginning within 2 months of valve rep/acemenf results in mortality rates of 40-50%, whereas rates are only 10-20% in later-onset cases."INFECTIVE ENDOCARDITISEtiology* Native valve endocarditis (NVE):o Community acquired: Streptococcus {S. viridans; S. gallolyticus; other non-group A, groupable streptococci and Abiotrophia spp).o Health care associated: Staphylococcus aureus.Endocarditis in IV drug abusers:o Right sided. Staphylococcus aureus.o Left sided: Enterococci and Staphylococcus aureusEarly prosthetic valve endocarditis (PVE): Coagulase negative Staphylococci.Late prosthetic valve endocarditis (PVE): Streptococcus viridians.Subacute endocarditis: Streptococcus viridians.Clinical FeaturesFever, chills and sweatsAnorexia, weight loss, malaiseMyalgias, arthralgiasNew/worsened regurgitant murmurArterial emboliSplenomegalyClubbingNeurologic manifestationsPeripheral manifestations {Osier's nodes, subungual hemorrhages, Janeway lesions, Roth's spots)Petechiae.Laboratory ManifestationsAnemiaLeukocytosisMicroscopic hematuriaElevated erythrocyte sedimentation rateElevated C-reactive protein levelRheumatoid factorCirculating immune complexesDecreased serum complementImportant Points:Strep viridans endocarditis causes subacute endocarditis.Survival for patients with NVE with Strep viridans is 85-90%.S. aureus with IV drug abuse survival rate is 85-90%.PVE mortality is 40-50% early onset and 10% in late onset cases.Subacute endocarditis follows indolent course slow cardiac damage, rarely metastasizes, complicated by embolic event or mycotic aneurysm.Acute endocarditis causes hectic fever, rapid cardiac damage, hematogenous spread to extracardiac sites and death if untreated.S. aureus endocarditis causes:o Vegetations >10 mm.o Increased risk of embolisation,o Microabscesses in Brain and Meninges.Mycotic aneurysms, microabscesses in brain, glomerulonephritis can occur.Cardiac failure, perivalvular abscess, pericarditis, conduction blocks.The Duke Criteria for the Clinical Diagnosis of Infective EndocarditisMajor Criteria1. Positive blood cultureA). Typical microorganism for infective endocarditis from two separate blood cultures.Viridans streptococci, Streptococcus gallolyticus, HACEK group, Staphybcoccus aureus, orCommunity-acquired enterococci in the absence of a primary focus, orB). Persistently positive blood culture, defined as recovery of a microorganism consistent with infective endocarditis from:*. Blood cultures drawn >12 h apart; or*. All of 3 or a majority of >4 separate blood cultures, with first and last drawn at least 1 h apart.C). Single positive blood culture for Coxiella burnedi or phase I IgG antibody titer of >1:800.2. Evidence of Endocardial InvolvementA) Positive echocardiogram*. Oscillating intracardiac mass on valve or supporting structures or in the path of regurgitant jets or in implanted material, in the absence of an alternative anatomic explanation, or*. Abscess, or*. New partial dehiscence of prosthetic valve.B) New valvular regurgitation {increase or change in preexisting murmur not sufficient).Minor Criteria1. Predisposition. Predisposing heart condition or injection drug use.2. Fever >38.0degC (>100.4degF).3. Vascular phenomena. Major arterial emboli, septic pulmonary infarcts, mycotic aneurysm, intracranial hemorrhage, conjunctival hemorrhages, Janeway lesions.4. Immunologic phenomena: Glomerulonephritis, Osier's nodes, Roth's spots, rheumatoid factor.5. Microbiologic evidence: Positive blood culture but not meeting major criterion as noted previously*" or serologic evidence of active infection with organism consistent with infective endocarditis.Poor Prognostic FactorsOlder ageSevere comorbid conditionsDiabetesDelayed diagnosisProsthetic valvesInvolvement of aortic valveInvasive infections (Staph aureus)Antibiotic-resistant pathogens (P aeruginosa, yeast)Intracardiac complicationsMajor neurologic complications.
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