Molecular epidemiology of brucellosis in northern Tanzania
Halliday and Haydon
This project will develop the evidence-base to inform the use of Brucella vaccines in sub-Saharan Africa and build capacity in Tanzanian laboratories to generate critical Brucella typing data. The research will be conducted hand-in-hand with Tanzanian government scientists charged with formulating national policies for the control of brucellosis.
Brucellosis is a disease caused by a number of species of bacteria collectively called Brucella. Brucellosis is one of most widespread human diseases acquired from animals, and is one of the highest priority animal diseases in Africa. Brucellosis infects many animal species, including key livestock species - cattle, sheep, and goats - and most human infections are acquired through direct contact with livestock or via indirect transmission through untreated milk products. Brucellosis has wide-ranging impacts that include animal losses due to abortion, lost milk production, killing of infected animals, and human illness causing reduced work capacity.
One third of the human population of sub-Saharan Africa lives and works closely with livestock. Areas with both high livestock populations and demand for livestock products offer the greatest opportunity for livestock to serve as a pathway out of poverty. Tanzania has been identified as a hotspot for endemic zoonoses burden, poverty burden and reliance on livestock.
Sub-Saharan Africa also has the worlds fastest growing human population and highly dynamic societies undergoing rapid urbanization. Changes in connections between urban and rural populations and the supply of animal products into urban areas could lead to significant shifts in patterns of exposure to zoonotic diseases such as brucellosis.
Control programmes implemented previously demonstrate that the use of existing tools for brucellosis control can markedly improve the livelihoods of the poor communities that are most affected by brucellosis. However important gaps remain in our understanding of the epidemiology of brucellosis in sub-Saharan Africa.
To develop practical plans for brucellosis control it is crucial to understand which host species are infected by which Brucella species, and which routes are most important in transmitting brucellosis to humans in rural environments, towns and rapidly expanding cities.
This project will generate data, and tools, provide training, and establish and enhance national and trans-national partnerships critical to the development and implementation of a brucellosis control program for Tanzania. The development of diagnostic capacity in Tanzanian research laboratories necessary for species-level diagnosis of Brucella will enable detection of animal infections and - crucially - the identification and characterisation of the Brucella species present in different livestock and human populations.
These data will be critical for identifying the ruminant species that act as sources of human infection and the Brucella species most responsible for human disease in rural and urban environments of northern Tanzania. This project will provide the first large systematic evidence base to guide which vaccine is best used in which different animal population.
In the short term, this project will build significant laboratory diagnostic capacity and expertise in Tanzania and strengthen academic links between UK and Tanzanian laboratories working on brucellosis. Our team includes policy-makers in Tanzanian government and will help ensure that research findings are made directly available to those who need to know most (including vaccine producers).
The project will provide the evidence-base specifically identified by the Tanzanian government to formulate national brucellosis control policy and place Tanzania on the roadmap for progressive control of this high priority disease.
First published: 18 August 2014