2.) What is the Pathophysiology of Rheumatic Fever/ Rheumatic Heart Disease?

Organism Factors Based on evidence, ARF is exclusively caused by URTI ( Group A Streptococci). It has been postulated that a series of preceding streptococcal infections is needed to “prime” the immune system to the final infection that directly causes the disease.

The Immune Response Susceptible host encounters a group A streptococcus Auto immune reaction occurs Leads to human tissue damage as a result of cross-reactivity between epitopes on the organism and host.

Molecular mimicry Group A Streptococci- has epitopes present in the M protein Similar molecules – human myosin, tropomyosin, keratin, actin, laminin, vimentin, and NAG. Basis for Autoimmune response T cell sensitization T cells recalled following subsequent exposure

Valvular Damage Laminin- found in cardiac endothelium and is recognized by anti-myosin, anti-M protein, T cells. Antibodies to cardiac valve cross react with NAG

4.) What is the differential Diagnosis for the cause of Fever?

Infective Endocarditis Prototypic lesion- vegetation Infection most commonly involves the heart valve Organisms that cause this generally enter the bloodstream from mucosal surfaces, the skin, or sites of focal infection.

Infective Endocarditis Etiologies: – Health Care Associated – bacteremia arising from IV catheterizations, nosocomial wound, UTI’s, chronic invasive procedures – Prosthetic Valve endocarditis- intraoperative contamination – Injection drug users-

Infective Endocarditis Highly variable clinical manifestations Causative microorganism primarily responsible for acute course incluse B-hemolytic streptococci, S. aureus, and Pneumococci. Febrile patient with valvular abnormalities or behavior pattern that predispose ( injection drug use) Bacteremia with organisms that frequently causes endocarditis

Infective Endocarditis degrees Celcius fever for the acute course Fever may be blunted or absent in patients who are elderly or severely debilitated.