Zoonotic tick-borne pathogens contribute to acute febrile illness in rural South Africa

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PROJECT SUMMARY/ABSTRACT SECTION More than 60% of infectious diseases in humans are spread from animals, often by an arthropod vector. In recent years, vector-borne viral, bacterial and parasitic diseases have emerged or re-emerged in many regions causing global health and economic concerns. The ecology and epidemiology of these diseases are affected by the interrelations between the pathogen, the host and the environment. Vector-borne infections transmitted from wildlife reservoir species to domestic animals or humans are thus of major concern. The Mnisi One Health Platform was established to facilitate research at the cusp of human/livestock/wildlife interface. The Mnisi community is a rural, impoverished area that is situated in the Mpumalanga Province, South Africa. The community shares 75% of its boundary with wildlife reserves, including the Kruger National Park, and provides an environment where there is interaction between humans and domestic and wild animals. The Hans Hoheisen Wildlife Research Station is a well-equipped laboratory on site enabling researchers to process samples on site. The community supports research activities and interventions in return for assistance in an array of health related areas. Using this rich infrastructure, we plan to test the hypothesis that a significant proportion of non-malarial acute febrile illness (AFI) in the Mnisi community can be attributed to tick-borne zoonoses. Some of our early findings suggest that zoonoses, particularly tick bite fever, Q fever and human granulocytic anaplasmosis need to be considered in the investigation of febrile patients presenting for care in Mnisi. In an effort to address this, we plan to study tick-borne pathogens at the wildlife-livestock-human interface, and to identify potential aetiological agents of febrile illnesses in this community. Our first goal is to test samples from human patients who present with non-malarial AFI at the health clinics in the Mnisi community for the presence of zoonotic pathogens using a metagenomic approach. Next we will analyze the microbiome of ticks to determine which tick- borne pathogens are circulating in the community. We believe that ticks act as a focal concentrator of pathogens circulating in the community, and therefore will provide a representative sampling of tick-borne pathogens. Unknown organisms that are detected in both sample sets will be identified as putative pathogens. We then plan to examine a range of samples for the presence of the spotted-fever group rickettsiae, C. burnetii, A. phagocytophilum, Bartonella spp and any other significant putative pathogens identified. The genetic diversity of the organisms identified will be analyzed. The putative tick vector(s) and reservoir hosts will also be identified. Based on this, diagnostic tests can be implemented in rural communities ensuring appropriate interventions and benefiting human health and well-being. This proposal focuses on zoonotic tick-borne diseases in South Africa; our knowledge base of zoonotic tick-borne pathogens impacting human health in South Africa will be expanded and our understanding of the challenges faced by rural communities living at the interface will be enhanced. This will be of value not only for South Africa, but also for other African countries.