A REVIEW OF ENDOCARDITIS IN ACQUIRED-IMMUNODEFICIENCY-SYNDROME AND HUMAN-IMMUNODEFICIENCY-VIRUS INFECTION

Non-bacterial thrombotic endocarditis (NBTE) was frequently identified in early post-mortem studies of patients with HIV infection, but has not been reported since 1989. The reason for this apparent decline is not clear, but it is possible that the prevalence of the condition was overestimated in the past. We have found no evidence of NBTE in our s eries of 110 autopsies on subjects from all major risk groups and at v arious stages of immune deficiency [intravenous drug user (IVDU)-AIDS 35% (39/110), IVDU-pre AIDS 36% (40/110), homosexual-AIDS 25% (28/110) , blood product recipients-AIDS 1.8% (2/110), African 0.9% (1/110)]. I nfective endocarditis (IE) in HIV infection occurs almost exclusively in intravenous drug users and is rare in other HIV-positive patients. However, asymptomatic HIV infection appears to have little effect on t he susceptibility to or the mortality fr om endocarditis and it is, th erefore, appropriate to institute antimicrobial treatment in these cas es. The majority (54.4%) of the 960 HIV-positive individuals in the Lo thian region of Scotland are young adults who contracted the virus thr ough IVDU around 1983. However, a prospective echocardiological study of 269 patients over four years (IVDU 69%, homosexual 18%, heterosexua l 8%, bisexual 3%, multiple risk factors 1%) has demonstrated only Sou r cases of infective endocarditis. We believe this reflects the preval ence of current parenteral drug we in our cohort which has fallen with the introduction of an oral drug replacement programme. In our experi ence, the incidence of IE mirrors the use of injection drugs, suggesti ng that this, rather than impaired immunity, is the most important ris k factor for the development of infective endocarditis in HIV-positive patients.