Parasitology

Research Article

Molecular epidemiology and phylogeography of Schistosoma mansoni around Lake Victoria

C. J. STANDLEYa1a2 c1, N. B. KABATEREINEa3, C. N. LANGEa4, N. J. S. LWAMBOa5 and J. R. STOTHARDa2

a1 Institute of Genetics, School of Biology, University of Nottingham, Nottingham NG7 2RD, UK

a2 Biomedical Parasitology Division, Department of Zoology, Natural History museum, Cromwell Road, London SW7 5BD, UK

a3 Vector Control Division, Ministry of Health, Kampala, Uganda

a4 Invertebrate Zoology Section, Nairobi National Museum, Museum Hill, P.O. Box 40658, Nairobi, Kenya

a5 National Institute for medical Research, Mwanza, Tanzania

SUMMARY

Intestinal schistosomiasis continues to be a major public health problem in sub-Saharan Africa, and is endemic in communities around Lake Victoria. Interest is growing in the molecular evolution and population genetic structure of Schistosoma mansoni and we describe a detailed analysis of the molecular epidemiology and phylogeography of S. mansoni from Lake Victoria. In total, 388 cytochrome oxidase 1 (COI) sequences were obtained from 25 sites along the Ugandan, Tanzanian and Kenyan shorelines of Lake Victoria, and 122 unique barcodes were identified; 9 corresponded to previously discovered barcodes from Lakes Victoria and Albert. A subset of the data, composed of COI sequences from miracidia from 10 individual children, was used for population genetics analyses; these results were corroborated by microsatellite analysis of 4 isolates of lab-passaged adult worms. Overall, 12 barcodes were found to be shared across all 3 countries, whereas the majority occurred singly and were locally restricted. The population genetics analyses were in agreement in revealing high diversity at the level of the human host and negligible population structuring by location. The lack of correlation between genetic distance and geographical distance in these data may be attributed to the confounding influence of high intra-individual diversity as well as human migration between communities.

(Received December 14 2009)

(Revised February 09 2010)

(Accepted April 06 2010)

(Online publication June 21 2010)

Correspondence:

c1 Corresponding author: Institute of Genetics, School of Biology, University of Nottingham, Nottingham NG7 2RD, UK. Tel: +0207 942 5566. Fax: +0207 942 5054. E-mail: c.standley@nhm.ac.uk

Metrics