Chronic High-Level Parasitemia in HIV–Infected Individuals With or Without Visceral Leishmaniasis in an Endemic Area in Northwest Ethiopia: Potential Superspreaders?

Abstract

Background HIV patients with recurrent visceral leishmaniasis (VL) could potentially drive Leishmania transmission in areas with anthroponotic transmission such as East-Africa, but studies are lacking. Leishmania parasitemia has been used as proxy for infectiousness. Methods This study is nested within the PreLeish prospective cohort study, following a total of 490 HIV infected individuals free of VL at enrollment for upto 24-37 months in North-West Ethiopia. Blood Leishmania PCR was done systematically. This case series reports on ten HIV-coinfected individuals with chronic VL (≥3 VL episodes during follow-up) for upto 37 months, and three individuals with asymptomatic Leishmania infection for upto 24 months. Results All ten chronic VL cases were male, on antiretroviral treatment, with 0-11 relapses before enrollment. Median baseline CD4 counts were 82 cells/µL. They displayed three to six VL treatment episodes over a period upto 37 months. Leishmania blood PCR levels were strongly positive for almost the entire follow-up time (median Ct value 26 (IQR 23-30), including during periods between VL treatment. Additionally, we describe three HIV-infected individuals with asymptomatic Leishmania infection and without VL history, with equally strong Leishmania parasitemia over a period of upto 24 months without developing VL. All were on antiretroviral treatment at enrollment, with baseline CD4 counts ranging from 78 to 350 cells/µL. Conclusion These are the first data on chronic parasitemia in HIV-infected individuals from L donovani endemic areas. HIV patients with asymptomatic and symptomatic Leishmania infection could potentially be highly infectious and constitute Leishmania superspreaders. Xenodiagnosis studies are required to confirm infectiousness.