IVI and Tanzania


Previous Collaboration


Typhoid Surveillance in sub-Saharan Africa Program (TSAP)

From 2010 to 2014, IVI’s The Typhoid Fever Surveillance in Africa Program (TSAP) obtained comparable incidence data on typhoid fever and invasive nontyphoidal Salmonella (iNTS) disease in sub-Saharan Africa through standardized surveillance in ten countries (Burkina Faso, Ethiopia, Ghana, Guinea-Bissau, Kenya, Madagascar, Senegal, South Africa, Sudan, and Tanzania).


In Tanzania, TSAP ran from 2011 to 2013, conducting surveillance in the cities of Moshi, Muheza, and Tanga in collaboration with Kilimanjaro Christian Medical Centre and Duke University Medical Center of the United States. The studies in Moshi and Tanga were a follow-up to a 2007-2009 IVI study which examined the cost of illness from typhoid and other salmonella infections, and public knowledge and practices regarding these infections.


Each TSAP site conducted passive surveillance for bloodstream infections among febrile patients to isolate and identify aerobic bacteria from the patients’ blood. Healthcare utilization surveys were conducted to adjust population denominators in incidence calculations for differing healthcare utilization patterns and improve comparability of incidence rates across sites. The results of TSAP indicated that enteric fever caused by Salmonella Typhi and non-typhoidal Salmonella are significant problems in Africa and that the prevalence of multi-drug resistance may limit appropriate treatment options.


Along with its new disease burden discoveries, TSAP and its collaborators strengthened local surveillance capacities at multiple sites across sub-Saharan Africa, creating a system that has improved bacterial disease diagnostics, disease surveillance, reporting, and analysis systems in the region. 


Cholera Vaccine Effectiveness Trial

From 2009 to 2010, IVI conducted an oral cholera vaccine (OCV) effectiveness study in Tanzania in collaboration with the WHO, the Zanzibar Ministry of Health, and the Swiss Tropical and Public Health Institute with support from Sweden’s SIDA. 


In January and February 2009, approximately 30,000 people aged 2 and over received two doses of the Dukoral OCV at study sites on Zanzibar and Pemba islands. 


The result of the effectiveness trial showed the vaccine provided 70% protection during the first year of follow-up. IVI conducted an analysis of herd immunity conferred by the vaccine and found clear evidence of protection in those who were not vaccinated against cholera. This additional and indirect benefit of oral cholera vaccines helped further develop the case for the use of OCV, especially in outbreak situations.