Parasitology

Research Article

Latent Trypanosoma brucei gambiense foci in Uganda: a silent epidemic in children and adults?

S. L. WASTLINGa1, K. PICOZZIa1, C. WAMBOGAa2, B. VON WISSMANNa1, C. AMONGI-ACCUPa1a3, N. A. WARDROPa1a4, J. R. STOTHARDa5, A. KAKEMBOa2 and S. C. WELBURNa1 c1

a1 Centre for Infectious Diseases, Division of Pathway Medicine, School of Biomedical Sciences, College of Medicine and Veterinary Medicine, The University of Edinburgh, Summerhall, Edinburgh, EH9 1QH

a2 Ministry of Health, Department of National Disease Control, PO Box 7272, Nakasero, Kampala, Uganda

a3 Faculty of Veterinary Medicine, Makerere University, PO Box 7062, Kampala, Uganda

a4 School of Geography, Shackleton Building, Highfield Campus, University of Southampton, Southampton, S017 1BJ

a5 Wolfson Wellcome Biomedical Laboratories, Department of Zoology, Natural History Museum, Cromwell Road, London, SW7 5BD

SUMMARY

Trypanosoma brucei gambiense sleeping sickness follows a long asymptomatic phase and persists in ancient foci from which epidemic clinical disease arises. A putative focus of T. b. gambiense infections has been identified, initially in mothers and young children, on the Lake Albert shoreline of Western Uganda leading to mass screening of 6207 individuals in September 2008. T. b. gambiense infections were identified by Card Agglutination Test for Trypanosomiasis (CATT) and sub-species-specific PCR although parasitological methods failed to confirm any patent trypanosome infections. In April 2009, CATT positives were re-visited; diagnosis of individuals by CATT and PCR was unstable over the two time points and parasites remained undetected, even using mini Anion Exchange Centrifugation Technique (mAECT). These observations suggest the possibility of a silent focus of disease, where all infected individuals are in a latent stage, and highlight our limited understanding of the local natural history and disease progression of T. b. gambiense in children and adults.

(Received November 30 2010)

(Revised November 30 2010)

(Accepted January 31 2011)

(Online publication April 18 2011)

Correspondence:

c1 Corresponding author: Professor Sue Welburn, Centre for Infectious Diseases, Division of Pathway Medicine, School of Biomedical Sciences, College of Medicine and Veterinary Medicine, University of Edinburgh, Summerhall, Edinburgh, EH9 1QH. Tel: +44 131 650 6287; E-mail: sue.welburn@ed.ac.uk

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