a1 Centre for Parasitology and Disease, Biomedical Sciences Research Institute, School of Environment and Life Sciences, University of Salford, Salford M5 4WT, UK
a2 Faculty of Veterinary Medicine, Division of Infection and Immunity, University of Glasgow, Bearsden Road, Glasgow G61 1QH, Scotland, UK
Human sleeping sickness in Africa, caused by Trypanosoma brucei spp. raises a number of questions. Despite the widespread distribution of the tsetse vectors and animal trypanosomiasis, human disease is only found in discrete foci which periodically give rise to epidemics followed by periods of endemicity A key to unravelling this puzzle is a detailed knowledge of the aetiological agents responsible for different patterns of disease – knowledge that is difficult to achieve using traditional microscopy. The science of molecular epidemiology has developed a range of tools which have enabled us to accurately identify taxonomic groups at all levels (species, subspecies, populations, strains and isolates). Using these tools, we can now investigate the genetic interactions within and between populations of Trypanosoma brucei and gain an understanding of the distinction between human- and nonhuman-infective subspecies. In this review, we discuss the development of these tools, their advantages and disadvantages and describe how they have been used to understand parasite genetic diversity, the origin of epidemics, the role of reservoir hosts and the population structure. Using the specific case of T.b. rhodesiense in Uganda, we illustrate how molecular epidemiology has enabled us to construct a more detailed understanding of the origins, generation and dynamics of sleeping sickness epidemics.
(Received January 30 2009)
(Revised May 01 2009)
(Accepted May 01 2009)
(Online publication June 26 2009)
c1 Corresponding author: Centre for Parasitology and Disease, Biomedical Sciences Research Institute, School of Environment and Life Sciences, University of Salford, Salford M5 4WT, UK. Tel: +0161 295 3371. Fax: +0161 295 5015. E-mail: firstname.lastname@example.org