New Agriculturist: Focus on... Addressing zoonotic diseases and livelihoods in Tanzania

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Addressing zoonotic diseases and livelihoods in Tanzania

Addressing zoonotic diseases and livelihoods in Tanzania

Animals and people in Ruaha have been forced to share the same community water sources
© Annette Roug

With water becoming increasingly scarce, animals and people in Tanzania's Ruaha ecosystem have been forced to share the same community water sources, resulting in contamination of drinking water and an increased risk of transmission of zoonotic diseases. Many pastoralists in the region also consume raw blood, milk and meat, further increasing their risk of exposure to pathogens from animals.

Since 2006, the Health for Animals and Livelihood Improvement (HALI) project has been investigating patterns of diseases such as bovine tuberculosis (BTB) in livestock, wildlife, people and the environment. "Understanding the dynamics of zoonotic disease agents in human, livestock and wildlife populations, and how they relate to land use change and environmental management, is critical to developing mitigation strategies," states Woutrina Miller, HALI co-principal investigator.

Tracking transmission

The HALI project team recognised that the health of livestock, wildlife and people is inextricably linked, leading them to adopt a collaborative 'One Health' approach involving professionals from multiple disciplines including veterinarians, physicians, epidemiologists, sociologists and economists. Using this 'One Health' approach, HALI has been working on integrated policy interventions that simultaneously tackle multiple and interacting causes of poor health (unsafe water, lack of sanitation, food insecurity) in order to yield larger health benefits than policies that target each factor in isolation. "A One Health approach also has to be community-based," explains Harrison Sadiki, HALI's project coordinator. "We need to research what the pastoralist communities feel they need most, and this has been one of the project priorities."

The HALI team investigated pathogens at water sites used by people and their livestock
© Alison Kent

With information on food consumption, water use habits, access to healthcare, and illnesses in animals and people, HALI has tailored education efforts for BTB as a priority disease. Preliminary findings indicated that more than two-thirds of pastoral households did not believe that illnesses could be contracted from livestock and most did not consider sharing water sources with livestock or wildlife a health risk. "People never knew about the transmission dynamics between people, livestock and wildlife," Sadiki explains.

Using cutting edge molecular methods, the HALI team has been able to show that the same strains of BTB are present in animals and people in the region. "The DNA typing methods have been established in Tanzania by Professor Kazwala, and we are now optimizing new methods to investigate under-recognized transmission routes," Woutrina Miller adds. These new technologies are being implemented at Sokoine University of Agriculture to build diagnostic capacity in-country. A similar approach was used when the HALI team investigated the waterborne faecal* pathogens Salmonella, Cryptosporidium and Giardia at water sites used by people and their livestock, highlighting the need for greater efforts to prevent contamination and minimise health risks.

Results of household surveys reported that cattle sickness, consumption of raw cow blood, and limited accessibility to water sources increased the probability of disease in pastoralist households. Households who reported drinking raw blood were at least four times more likely to report chronic diseases than those who didn't, while households with sick cattle were three times more likely to report disease than those without sick cattle. "One of our greatest achievements, through education, has been to change the behaviour of pastoralists," Sadiki adds. "It is part of their culture to drink raw blood, but many are no longer giving raw blood or milk to their children."

Strengthening health and livelihoods in a changing climate

To mitigate the impacts of zoonotic diseases, HALI is working to develop new health and environmental policy interventions. One example is decision support system models to demonstrate the potential impact of water management policies on water availability, animal health, and community livelihoods.

HALI has begun to research emerging diseases
© Liz van Wormer

Building on HALI's work in outreach and education, funding from the Livestock Climate Change Collaborative Research Support Program (LCC - CRSP) will help to address potential risks and resilience strategies associated with climate change. This funding will help strengthen the capacity of local livestock extension officers to provide herd health care, and through nutritional assessments and delivery of appropriate health education information using cell-phones and text messaging. "By working with our Tanzania partners to integrate novel mobile phone education delivery and follow up, we will simultaneously expand training opportunities and collect real time data on disease, nutrition and economic outcomes," Miller explains.

As part of USAID's Predict project, HALI is including research on emerging diseases. "We know that wildlife can be a reservoir for diseases of public health importance, but in order to predict, respond to and prevent the emergence of infectious diseases in humans, pathogens must be identified at their sources," Miller concludes. As part of the Predict project, HALI has equipped Sokoine University with a cutting edge molecular disease diagnostic laboratory, the first facility in Tanzania working to identify novel viruses and potentially emerging pathogens in wildlife.

Date published: November 2011