Exploring potential risk pathways with high risk groups for urban Rift Valley fever virus introduction, transmission, and persistence in two urban centers of Kenya

Rift Valley fever virus (RVFV) is a zoonotic arbovirus that has profound impact on domestic ruminants and can also be transmitted to humans via infected animal secretions. Urban areas in endemic regions across Africa have susceptible animal and human hosts, dense vector distributions, and source livestock (often from high risk locations to meet the demand for animal protein). Yet, there has never been a documented urban outbreak of RVF. To understand the likely risk of RVFV introduction to urban communities from their perspective and guide future initiatives, we conducted focus group discussions with slaughterhouse workers, slaughterhouse animal product traders, and livestock owners in Kisumu City and Ukunda Town in Kenya. For added perspective and data triangulation, in-depth interviews were conducted one-on-one with meat inspector veterinarians from selected slaughterhouses. A theoretical framework relevant to introduction, transmission, and potential persistence of RVF in urban areas is presented here. Urban livestock were primarily mentioned as business opportunities, but also had personal sentiment. In addition to slaughtering risks, perceived risk factors including consumption of fresh milk. High risk groups' knowledge and experience with RVFV and other zoonotic diseases impacted their consideration personal risk, with consensus towards lower risk in the urban setting compared to rural areas as determination of health risk was said to primarily rely on hygiene practices rather than the slaughtering process. Groups relied heavily on veterinarians to confirm animal health and meat safety, yet veterinarians reported difficulty in accessing RVFV diagnostics. We also identified vulnerable public health regulations including corruption in meat certification outside of the slaughterhouse system, and blood collected during slaughter being used for food and medicine, which could provide a means for direct RVFV community transmission. These factors, when compounded by diverse urban vector breeding habitats and dense human and animal populations, could create suitable conditions for RVFV to arrive an urban center via a viremic imported animal, transmit to locally owned animals and humans, and potentially adapt to secondary vectors and persist in the urban setting. This explorative qualitative study proposes risk pathways and provides initial insight towards determining how urban areas could adapt control measures and plan future initiatives to better understand urban RVF potential. Author summaryRift Valley fever is an important mosquito-borne zoonotic virus that can also be transmitted directly to humans via infected livestock. There has never been an urban outbreak of RVF, however, other arboviruses have caused devastating urban outbreaks driven by urban transmission cycles in vectors. This qualitative study aimed to explore and understand the potential risk of Rift Valley fever in the urban context from the perspective of high risk groups. RVF has a complex epidemiology and urban centers of endemic regions may be particularly vulnerable as they import large quantities of livestock for slaughter and milk to meet the high urban demand for animal sourced foods and have dense host and vector populations. This qualitative study provides insights from the opinions and lived experiences of urban high risk groups including slaughterhouse affiliates, livestock owners, and veterinarians. We also demonstrate risks specific to RVFV transmission and regulatory vulnerabilities that would impact the ability to detect RVF disease introduction. The results of this study are intended to guide future initiatives aiming to investigate urban potential of RVF and infer how urban disease ecology could differ from what has been previously demonstrated in rural areas.

Automated summary

This qualitative study aimed to explore and understand the potential risk of Rift Valley fever in the urban context from the perspective of high risk groups, including slaughterhouse affiliates, livestock owners, and veterinarians in Kenya. The study found that urban areas, with their importation of large quantities of livestock and milk, dense host and vector populations, are vulnerable to RVFV transmission. This study provides initial insights and guidance for future initiatives to investigate and control RVF in urban areas.