Assessing the progress towards rabies elimination from Pemba Island, Tanzania
Rabies is a deadly disease endemic in dog populations across Africa. Although rabies can be eliminated through mass dog vaccination, there has been little investment in dog vaccination in Africa and there are few examples of local disease elimination on the continent. Recently the Tanzanian government embarked on a large-scale rabies elimination demonstration programme in Southern Tanzania based on annual mass dog vaccinations. As part of this programme three campaigns have been conducted on the island of Pemba (approximately 4000 dogs), yet rabies still persists in this isolated population. This study aims to identify causes of persistent foci of infection and determine what factors affect the time to eliminate such foci from Pemba, addressing the following questions: a) Where are foci of infection persisting on Pemba?, b) What factors enable disease persistence? and c) if rabies is eliminated from Pemba, how rapidly were foci eliminated and what factors determined time to elimination? Detailed contact tracing tracking localized rabies transmission are used to identify persistent foci of infection on the island. Survey data on dog ownership, data from vaccination campaigns and geographical data on landscape features and the distribution of the dog population are also compiled. Using these data, factors associated with persistent infection and the time to eliminate these foci will be identified. Pin-pointing the causes of persistence and determining the effort needed to eliminate rabies from a small island such as Pemba is important for demonstrating the practicality of elimination in African settings. Detailed description of challenges to rabies elimination will provide guidance for future programmes in Africa.