title: Transmission of Leishmania donovani in the Hills of Eastern Nepal, an Outbreak Investigation in Okhaldhunga and Bhojpur Districts.
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.
  
  
  RESULTS
  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
  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.
authors.affiliation: Department of Public Heath, Institute of Tropical Medicine, Antwerp, Belgium.
authors.forename: Bart
authors.initials: B
authors.lastname: Ostyn
authors.affiliation: Department of Internal Medicine, B.P. Koirala Institute of Health Sciences, Dharan, Nepal.
authors.forename: Surendra
authors.initials: S
authors.lastname: Uranw
authors.affiliation: Department of Microbiology, B.P. Koirala Institute of Health Sciences, Dharan, Nepal.
authors.forename: Narayan Raj
authors.initials: NR
authors.lastname: Bhattarai
authors.affiliation: Department of Microbiology, B.P. Koirala Institute of Health Sciences, Dharan, Nepal.
authors.forename: Murari L
authors.initials: ML
authors.lastname: Das
authors.affiliation: Department of Microbiology, B.P. Koirala Institute of Health Sciences, Dharan, Nepal.
authors.forename: Keshav
authors.initials: K
authors.lastname: Rai
authors.affiliation: Department of Public Heath, Institute of Tropical Medicine, Antwerp, Belgium.
authors.forename: Katrien
authors.initials: K
authors.lastname: Tersago
authors.affiliation: Epidemiology and Disease Control Division, Ministry of Health and Population (MOHP), Kathmandu, Nepal.
authors.forename: Yubraj
authors.initials: Y
authors.lastname: Pokhrel
authors.affiliation: Department of Biomedical Sciences, Institute of Tropical Medicine, Antwerp, Belgium.
authors.forename: Lies
authors.initials: L
authors.lastname: Durnez
authors.affiliation: Epidemiology and Disease Control Division, Ministry of Health and Population (MOHP), Kathmandu, Nepal.
authors.forename: Baburam
authors.initials: B
authors.lastname: Marasini
authors.affiliation: Department of Biomedical Sciences, Institute of Tropical Medicine, Antwerp, Belgium.
authors.forename: Gert
authors.initials: G
authors.lastname: Van der Auwera
authors.affiliation: Department of Biomedical Sciences, Institute of Tropical Medicine, Antwerp, Belgium; Department of Biomedical Sciences, University of Antwerp, Antwerp, Belgium.
authors.forename: Jean-Claude
authors.initials: JC
authors.lastname: Dujardin
authors.affiliation: Department of Biomedical Sciences, University of Antwerp, Antwerp, Belgium.
authors.forename: Marc
authors.initials: M
authors.lastname: Coosemans
authors.affiliation: Department of Control of Neglected Tropical Diseases, World Health Organization (WHO), Geneva, Switzerland.
authors.forename: Daniel
authors.initials: D
authors.lastname: Argaw
authors.affiliation: Department of Public Heath, Institute of Tropical Medicine, Antwerp, Belgium.
authors.forename: Marleen
authors.initials: M
authors.lastname: Boelaert
authors.affiliation: Department of Internal Medicine, B.P. Koirala Institute of Health Sciences, Dharan, Nepal.
authors.forename: Suman
authors.initials: S
authors.lastname: Rijal
mesh_terms: D000293:Adolescent; D000328:Adult; D000913:Antibodies, Protozoan; D016022:Case-Control Studies; D002396:Catechols; D002648:Child; D002675:Child, Preschool; D016000:Cluster Analysis; D004196:Disease Outbreaks; D005260:Female; D006801:Humans; D007223:Infant; D007893:Leishmania donovani; D007898:Leishmaniasis, Visceral / Q000453:epidemiology / Q000469:parasitology / Q000635:transmission*; D008297:Male; D008875:Middle Aged; D009390:Nepal / Q000453:epidemiology; D012307:Risk Factors; D013844:Thiazoles; D013997:Time Factors; D055815:Young Adult
chemical_list: C529061:2-(4,5-dihydro-1,3-thiazol-2-ylthio)-1-(3,4-dihydroxyphenyl)ethanone; D000913:Antibodies, Protozoan; D002396:Catechols; D013844:Thiazoles