Transmission dynamics and epidemiology of Rift Valley fever virus in northern Tanzania - ABSTRACT Rift Valley fever virus (RVFV) is an emerging arboviral pathogen and the cause of Rift Valley fever (RVF) in animals and humans. RVF has been reported across much of the African continent and is designated as a priority disease by international organizations due to its epidemic potential and the lack of effective countermeasures. The epidemiology of RVF has particular characteristics, with sudden large outbreaks in animals and humans occurring in spatially and temporally divergent patterns followed by long periods – called the inter-epizootic or inter-epidemic periods (IEP) – where disease activity is purportedly inapparent. Yet enhanced surveillance studies consistently show that the IEP is characterized by continuous disease transmission within susceptible hosts, and this transmission cycle is hypothesized as one mechanism for RVFV persistence during long IEPs. To this end, this project aims to gain insight into the inter-epidemic transmission pathways that result in RVF for livestock and human populations within the Kilimanjaro Region of Tanzania – where prior work by our One Health consortium described an outbreak of RVF among cattle that was contemporaneous with severe cases in humans. This project will: 1) define the prevalence of RVFV for livestock and humans in Kilimanjaro across different socio-ecological zones (e.g. rural, peri-urban, peri-urban, elevation) and exposures (e.g. socio- demographics, local mosquito composition and density); 2) systematically survey the milk value chain in Kilimanjaro to the assess the infectious nature of cow's milk; and 3) leverage data collected during the award period to construct mathematical models that reconstruct the transmission dynamics and epidemiology of RVF in Kilimanjaro. Results from this project will identify the pathways that contributes to RVFV persistence during the IEP and may inform the development of actionable interventions that interrupt this cryptic transmission cycle. This project has direct relevance to the US NIH's continued efforts to conduct foundational research on emerging infectious pathogens and the diseases they cause. This career development award will provide the candidate with expertise in conducting One Health research, and he will acquire advanced skillsets in infectious disease modeling, all of which are necessary for his long-term career goal to become a leader in advancing understanding of zoonotic diseases and implementing mitigation strategies to effectively stop disease transmission. The primary mentor for this award is Dr. Matthew Rubach, an accomplished researcher with substantial experience in conducting clinical research on causes of severe febrile illness and zoonotic diseases in Tanzania. A complementary and diverse group of mentors will provide guidance in One Health (Dr. Jo Halliday), veterinary health (Dr. Gabriel Shirima), and infectious disease modeling (Dr. Paul Johnson). The candidate will use the outstanding resource and interdisciplinary working groups at Duke University, Kilimanjaro Christian Medical Centre, and the University of Glasgow to launch his career as an independent physician-scientist.
