Preprint Article Version 1 This version is not peer-reviewed

Serological Evidence of Cryptic Rift Valley Fever Virus Transmission among Humans and Livestock in Central Highlands of Kenya

Version 1 : Received: 8 October 2024 / Approved: 8 October 2024 / Online: 8 October 2024 (13:49:26 CEST)

How to cite: Situma, S.; Omondi, E.; Nyakarahuka, L.; Odinoh, R.; Mweu, M.; Murithi, M.; Mulinge, M. M.; Clancey, E.; Dawa, J.; Ngere, I.; Osoro, E.; Gunn, B.; Konongoi, L.; Ashimosi, S.; Bakamutumaho, B.; Breiman, R. F.; Njenga, K. Serological Evidence of Cryptic Rift Valley Fever Virus Transmission among Humans and Livestock in Central Highlands of Kenya. Preprints 2024, 2024100587. https://doi.org/10.20944/preprints202410.0587.v1 Situma, S.; Omondi, E.; Nyakarahuka, L.; Odinoh, R.; Mweu, M.; Murithi, M.; Mulinge, M. M.; Clancey, E.; Dawa, J.; Ngere, I.; Osoro, E.; Gunn, B.; Konongoi, L.; Ashimosi, S.; Bakamutumaho, B.; Breiman, R. F.; Njenga, K. Serological Evidence of Cryptic Rift Valley Fever Virus Transmission among Humans and Livestock in Central Highlands of Kenya. Preprints 2024, 2024100587. https://doi.org/10.20944/preprints202410.0587.v1

Abstract

Although highlands of East Africa lack the geo-ecological landmarks of Rift Valley fever (RVF) disease hotspots to participate in cyclic RVF epidemics, they have recently reported growing numbers of small RVF clusters. Here, we investigated whether RVF cycling occurred among livestock and humans in the central highlands of Kenya during inter-epidemic periods. A 2-year prospective hospital-based study among febrile patients (March 2022 - February 2024) in Murang’a County of Kenya, was followed by a cross-sectional human-animal survey. A total of 1,468 febrile patients were enrolled at two clinics and sera tested for RVF virus RNA and antiviral antibodies. In the cross-sectional study, humans (n=282) and livestock (n=706) from randomly selected households were tested and questionnaire data used to investigate sociodemographic and environmental risk factors by multivariate logistic regression. No human (n=1,750) or livestock (n=706) sera tested positive for RVFV RNA. However, 4.4% livestock and 2.0% humans tested positive for anti-RVFV IgG, including 0.27% febrile patients who showed 4-fold IgG increase and 2.4% young livestock (<12 months old), indicating recent virus exposure. Among humans, odds of RVF exposure increased significantly (P<0.05, 95% CI) in males (aOR:4.77, 2.08–12.4), those consuming raw milk (aOR 5.24,1.13–17.9), milkers (aOR:2.69, 1.23–6.36), and participants residing near quarries (aOR:2.4, 1.08–5.72). In livestock, sheep and goats were less likely to be seropositive (aOR: 0.27, 0.12–0.60) than cattle. The increase in RVF disease activities in the highlands represents widening geographic dispersal of the virus, and greater risk of more widespread RVF epidemics in future.

Keywords

arbovirus; cryptic transmission; Rift Valley Fever virus; non-epidemic period

Subject

Public Health and Healthcare, Public Health and Health Services

Comments (0)

We encourage comments and feedback from a broad range of readers. See criteria for comments and our Diversity statement.

Leave a public comment
Send a private comment to the author(s)
* All users must log in before leaving a comment
Views 0
Downloads 0
Comments 0


×
Alerts
Notify me about updates to this article or when a peer-reviewed version is published.
We use cookies on our website to ensure you get the best experience.
Read more about our cookies here.