Role of PCR in diagnosis and prognosis of visceral leishmaniasis in patients coinfected with human immunodeficiency virus type 1

A group of 76 consecutive human immunodeficiency virus (HIV)-positive patie nts with fever of unknown origin (n = 52) or fever associated with pulmonar y diseases was evaluated in order to assess the usefulness of PCR with peri pheral blood in the diagnosis and follow-up of visceral leishmaniasis. We i dentified 10 cases of visceral leishmaniasis among the 52 patients with fev er of unknown origin. At the time of diagnosis, all were parasitemic by PCR with peripheral blood. During follow-up, a progressive decline in parasite mia was observed under therapy, and all patients became PCR negative after a median of 5 weeks (range, 6 to 21 weeks). However, in eight of nine patie nts monitored for a median period of 88 weeks (range, 33 to 110 weeks), vis ceral leishmaniasis relapsed, with positive results by PCR with peripheral blood reappearing 1 to 2 weeks before the clinical onset of disease. Eight Leishmania infantum and two Leishmania donovani infections were identified by PCR-restriction fragment length polymorphism analysis. PCR with peripher al blood is a reliable method for diagnosis of visceral leishmaniasis in HI V-infected patients. During follow-up, it substantially reduces the need fo r traditional invasive tests to assess parasitological response, while a po sitive PCR result is predictive of clinical relapse.