1. School of Life Sciences and Bioengineering, Nelson Mandela African Institution of Science and Technology, Arusha P.O. Box 447, Tanzania
2. Department of Biological Sciences, Dar es Salaam University College of Education, Dar es Salaam P.O. Box 2329, Tanzania
3. Department of Public Health, Institute of Tropical Medicine Antwerpen, Kronenburgstraat 43, 2000 Antwerpen, Belgium
4. Department of Infectious Disease Epidemiology, Bernhard Nocht lnstitute for Tropical Medicine, Bernhard-Nocht-Straße 74, 20359 Hamburg, Germany
5. German Center for Infection Research (DZIF), 38124 Hamburg, Germany