Acta Tropica 92 (2004) 77–82 Short communication Detection of high rates of in-village transmission of Leishmania donovani in eastern Sudan M.M. Hassan a,b , F.M.A. Elraba’a a , R.D. Ward c , R.D.C. Maingon c , D.A. Elnaiem a,c,* a Department of Zoology, Faculty of Science, University of Khartoum, P. O. Box 321, Khartoum, Sudan b Khartoum College of Medical sciences, Aljerief West, 1st Block Number 398, P. O. Box 10995, Khartoum, Sudan c School of Life Sciences, Keele University, Staffordshire ST5 5BG, UK Received 18 August 2003; received in revised form 2 June 2004; accepted 3 June 2004 Available online 8 July 2004 Keywords: Leishmania donovani; Sandflies; Visceral leishmaniasis; Epidemiology; Bednets; Sudan Visceral leishmaniasis (VL; kala azar), caused by Leishmania donovani and transmitted by Phlebotmus orientalis, is a major health problem in eastern and southern Sudan, where recent epidemics of the dis- ease claimed the lives of more than 100,000 people (Seamann et al., 1996; Elnaiem et al., 2003). Pre- vious studies carried out in these foci demonstrated that the vector of VL thrives mainly in woodland dominated by Acacia seyal and Balanites aegyptiaca trees Hoogstraal and Heyneman, 1969; Schorscher and Goris, 1992; Elnaiem et al., 1997; Thomson et al., 1999). In this habitat, we found high rates of infection of L. donovani in P. orientalis (Elnaiem et al., 1998) and provided evidence that the Egyptian mongoose (Herpestes ichneumon) is a silvatic reservoir host of the parasite (Elnaiem et al., 2001). * Corresponding author. Present address: Department of Ento- mology, University of California at Davis, 1 Shields Avenue, 367 Briggs Hall, Davis, CA 956161, USA. Tel.: +1 530 752 7333; fax: +1 530 752 1537. E-mail addresses: daelnaiem@ucdavis.edu, dialnaiem@hotmail.com (D.A. Elnaiem). Because of the high association of P. orientalis with un-inhabited woodland, it has been thought that peo- ple usually contract L. donovani when they visit these habitats. However, this notion could not account for the high incidence rates of VL amongst children, who are known to be resident inside their villages through- out the year (Zijlstra et al., 1994). Recently, we presented the first evidence that active transmission of L. donovani may take place inside vil- lages in eastern Sudan (Elnaiem and Osman, 1998). Out of 13 P. orientalis females collected from Um- salala village, one individual was harbouring heavy infection of L. donovani. However, our data were not sufficient to determine the magnitude of the in-village transmission of the parasite. One argument that stood against the idea of in-village transmission of VL was the previous observation that the vector is found in very small numbers in this habitat (Zeese and Franke, 1987; Elnaiem et al., 1997). Here, we present results of a study carried out to determine the infection rates of L. donovani in P. ori- entalis, and evaluate the transmission potential of the parasite in 12 VL-endemic villages in eastern Sudan. 0001-706X/$ – see front matter © 2004 Elsevier B.V. All rights reserved. doi:10.1016/j.actatropica.2004.06.001