Value Chain Analysis and Exposure Assessment to Non- Typhoidal Salmonellosis for Pork Consumers in Rural Western Kenya

Abstract

With the increasing demand for pork in sub-Saharan Africa, it is crucial to enhance public health infrastructure supporting the rapidly growing pork value chains to prevent the emergence and re-emergence of foodborne diseases that could undermine the economic benefits accompanying this demand surge. Non-Typhoidal Salmonella (NTS) is a prominent cause of foodborne disease globally, with a significant burden observed in African sub-regions. Notably, pork is considered the second most significant source of human NTS in sub-Saharan Africa. Western Kenya, the country's second-largest pig-producing region, anticipates an increase in pork demand within the local community and as a significant supplier to distant urban centers like Nairobi. This projected growth is likely to drive production intensification, leading to novel production systems at the farm level and throughout the supply chain. However, the existing public health infrastructure may not have the capacity to mitigate the challenges that arise from these changes, thereby increasing the risk of pathogen emergence and spread. Several pathogens, notably NTS, Taenia solium, and Campylobacter spp., have been associated with substantial public health and economic burdens attributed to animal source foods, particularly pork. For instance, a recent study in Busia County identified NTS in 12.7% of pigs designated for slaughter. These NTS serotypes have been linked to widespread gastroenteritis outbreaks worldwide, leading to severe illnesses and fatalities. Consequently, this scenario poses an imminent risk to pork consumers and stakeholders dependent on the pork value chain. Addressing the sustainable development of rapidly expanding meat value chains necessitates an in-depth understanding of the emerging challenges within food systems. Currently, such comprehensive insights are lacking in this context. To bridge this gap, this thesis employs a combination of epidemiological and economic methodologies to assess the value chain's structure,