Transmission of Leishmania donovani in the Hills of Eastern Nepal, an outbreak investigation in Okhaldhunga and Bhojpur Districts

Bart Ostyn, Surendra Uranw, Narayan Raj Bhattarai, Murari L Das, Keshav Rai, Katrien Tersago, Yubraj Pokhrel, Lies Durnez, Baburam Marasini, Gerard Van der Auwera, Jean-Claude Dujardin, Marc Coosemans, Daniel Argaw, Marleen Boelaert, Suman Rijal

Research output: Contribution to journalA1: Web of Science-article

35 Downloads (Pure)

Abstract

BACKGROUND: In the Indian subcontinent, Visceral leishmaniasis is endemic in a geographical area coinciding with the Lower Gangetic Plain, at low altitude. VL occurring in residents of hill districts is therefore often considered the result of Leishmania donovani infection during travel. Early 2014 we conducted an outbreak investigation in Okhaldhunga and Bhojpur districts in the Nepal hills where increasing number of VL cases have been reported.

METHODOLOGY/PRINCIPAL FINDINGS: A house-to-house survey in six villages documented retrospectively 35 cases of Visceral Leishmaniasis (VL). Anti-Leishmania antibodies were found in 22/23 past-VL cases, in 40/416 (9.6%) persons without VL and in 12/155 (7.7%) domestic animals. An age- and sex- matched case-control study showed that exposure to known VL-endemic regions was no risk factor for VL, but having a VL case in the neighbourhood was. SSU-rDNA PCR for Leishmania sp. was positive in 24 (5%) of the human, in 18 (12%) of the animal samples and in 16 (14%) bloodfed female Phlebotomus argentipes sand flies. L. donovani was confirmed in two asymptomatic individuals and in one sand fly through hsp70-based sequencing.

CONCLUSIONS/SIGNIFICANCE: This is epidemiological and entomological evidence for ongoing local transmission of L. donovani in villages at an altitude above 600 meters in Nepal, in districts considered hitherto non-endemic for VL. The VL Elimination Initiative in Nepal should therefore consider extending its surveillance and control activities in order to assure VL elimination, and the risk map for VL should be redesigned.

Original languageEnglish
JournalPLoS Neglected Tropical Diseases
Volume9
Issue number8
Pages (from-to)e0003966
ISSN1935-2727
DOIs
Publication statusPublished - 2015

Fingerprint

Dive into the research topics of 'Transmission of <i>Leishmania donovani</i> in the Hills of Eastern Nepal, an outbreak investigation in Okhaldhunga and Bhojpur Districts'. Together they form a unique fingerprint.

Cite this