Quantifying heterogeneity in host-vector contact: tsetse (Glossina swynnertoni and G. pallidipes) host choice in Serengeti National Park, Tanzania

Auty, H. , Cleaveland, S. , Malele, I., Masoy, J., Lembo, T. , Bessell, P., Torr, S., Picozzi, K. and Welburn, S. C. (2016) Quantifying heterogeneity in host-vector contact: tsetse (Glossina swynnertoni and G. pallidipes) host choice in Serengeti National Park, Tanzania. PLoS ONE, 11(10), e0161291. (doi: 10.1371/journal.pone.0161291) (PMID:27706167) (PMCID:PMC5051720)

Abstract

Background: Identifying hosts of blood-feeding insect vectors is crucial in understanding their role in disease transmission. Rhodesian human African trypanosomiasis (rHAT), also known as acute sleeping sickness is caused by Trypanosoma brucei rhodesiense and transmitted by tsetse flies. The disease is commonly associated with wilderness areas of east and southern Africa. Such areas hold a diverse range of species which form communities of hosts for disease maintenance. The relative importance of different wildlife hosts remains unclear. This study quantified tsetse feeding preferences in a wilderness area of great host species richness, Serengeti National Park, Tanzania, assessing tsetse feeding and host density contemporaneously. Methods: Glossina swynnertoni and G. pallidipes were collected from six study sites. Bloodmeal sources were identified through matching Cytochrome B sequences amplified from bloodmeals from recently fed flies to published sequences. Densities of large mammal species in each site were quantified, and feeding indices calculated to assess the relative selection or avoidance of each host species by tsetse. Results: The host species most commonly identified in G. swynnertoni bloodmeals, warthog (94/220), buffalo (48/220) and giraffe (46/220), were found at relatively low densities (3-11/km2) and fed on up to 15 times more frequently than expected by their relative density. Wildebeest, zebra, impala and Thomson’s gazelle, found at the highest densities, were never identified in bloodmeals. Commonly identified hosts for G. pallidipes were buffalo (26/46), giraffe (9/46) and elephant (5/46). Conclusions: This study is the first to quantify tsetse host range by molecular analysis of tsetse diet with simultaneous assessment of host density in a wilderness area. Although G. swynnertoni and G. pallidipes can feed on a range of species, they are highly selective. Many host species are rarely fed on, despite being present in areas where tsetse are abundant. These feeding patterns, along with the ability of key host species to maintain and transmit T. b. rhodesiense, drive the epidemiology of rHAT in wilderness areas.

• Item Type: Articles
• Additional Information: Funding: The authors are grateful for support from DFID RNRRS Animal Health Programme (SCW, KP, SC, HA). HA was a beneficiary of an MRC studentship, awarded by University of Edinburgh
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Lembo, Dr Tiziana and Auty, Harriet and Bessell, Dr Paul and Cleaveland, Professor Sarah
• Authors: Auty, H., Cleaveland, S., Malele, I., Masoy, J., Lembo, T., Bessell, P., Torr, S., Picozzi, K., and Welburn, S. C.
• College/School: College of Medical Veterinary and Life Sciences > School of Biodiversity, One Health & Veterinary Medicine
• Journal Name: PLoS ONE
• Publisher: Public Library of Science
• ISSN: 1932-6203
• ISSN (Online): 1932-6203
• Copyright Holders: Copyright © 2016 Auty et al.
• First Published: First published in PLoS ONE 11(10): e0161291
• Publisher Policy: Reproduced under a Creative Commons License