Kala-azar as an AIDS-related opportunistic infection

Visceral leishmaniasis (kala-azar) is a worldwide disseminated protozoal in fection primarily transmitted by sand flies. Because host defense against t his intracellular infection is T-cell-dependent, kala-azar has predictably joined the list of AIDS-related opportunistic infections in endemic areas. The vast majority of patients with AIDS-associated kala-azar are currently found in southern Europe (the Mediterranean basin, especially Spain in inje ction drug users); future cases will inevitably arise in other endemic regi ons including India, East Africa and Sudan, and Brazil. In CD4 cell-deficie nt HIV-infected individuals, kala-azar likely represents recrudescence of p reviously controlled asymptomatic infection; in drug users, newly acquired infection may result from transmission via shared needles. Coinfected patie nts are frequently parasitemic and may show atypical clinical presentations , unusual multi-organ involvement, and absent antileishmanial antibodies. D iagnosis is made by microscopic examination or culture of aspirate or biops y of any involved tissue (primarily bone marrow) or by blood smear or cultu re. Conventional treatment (pentavalent antimonials) induces initial remiss ion in about 50% of patients; amphotericin B and its new lipid formulations appear more active. If suppressive maintenance therapy is not used, relaps e within 1 year is typical. In AIDS patients with a first episode of viscer al kala-azar, up to 25% die within 1 month if treatment is stopped. Optimal primary and secondary prophylaxis for AIDS-related kala-azar remain to be determined; life-long maintenance therapy is becoming an accepted approach.