Design of a Prospective Human–Animal Cohort Study to Evaluate the Role of Camels and Other Livestock Species in the Transmission of Brucella spp. to Humans in Kenya
Brucellosis remains a major zoonotic disease worldwide, with disproportionate burden in low- and middle-income countries where limited veterinary and healthcare infrastructure constrain effective control measures. However, its pathways of transmission are poorly understood. In pastoralist settings, we hypothesize that camels have a high burden of <i>Brucella</i> spp. and play a key role in spreading it to humans and other livestock. This manuscript presents a study protocol to quantify the relative contribution of various livestock species to brucellosis transmission and identify cost-effective control strategies in Kenya. Using probability-proportional-to-size sampling, we aimed to recruit a longitudinal cohort of 170 households and their herds per site in the Marsabit and Kajiado counties. Households rearing at least one livestock species (cattle, camels, goats, sheep) were eligible. Serum, milk, and vaginal swabs (from livestock), and serum (from humans) were collected for testing using Rose Bengal Test, ELISA, qPCR, and culture methods. Concurrently, surveillance for suspected brucellosis was conducted in study health facilities. A qualitative ethnographic study and livestock movement monitoring using GPS-collared animals were nested within the cohort. These data will be used to parameterize a multi-host, multi-species infectious disease model through Approximate Bayesian Computation. Through this One Health approach, our study will identify and optimize potential interventions and help inform the development of a comprehensive cost-effective national control program for brucellosis.
Authors
- Samoel Khamadi (ORCID: https://orcid.org/0000-0003-3050-5977)
- Bonventure Juma
- Samson Konongoi (ORCID: https://orcid.org/0000-0002-4615-334X)
- Scott L. Nuismer (ORCID: https://orcid.org/0000-0001-9817-0056)
- Peninah Munyua (ORCID: https://orcid.org/0000-0003-1950-8616)
- Felix J. Lankester (ORCID: https://orcid.org/0000-0002-0802-0693)
- Boku Bodha (ORCID: https://orcid.org/0000-0002-3788-9750)
- Dismas Oketch (ORCID: https://orcid.org/0000-0003-4601-1859)
- Dalmas Ochieng Omia (ORCID: https://orcid.org/0000-0001-6060-8470)
- Adrian M. Whatmore (ORCID: https://orcid.org/0000-0003-4218-156X)
- Ruth Njoroge
- Isaac Ngere (ORCID: https://orcid.org/0000-0002-6688-3390)
- Roland T. Ashford (ORCID: https://orcid.org/0000-0002-4281-6302)
- Athman Mwatondo (ORCID: https://orcid.org/0000-0002-3180-7013)
- John Njeru (ORCID: https://orcid.org/0000-0002-7087-0576)
- Walter Jaoko (ORCID: https://orcid.org/0000-0002-7134-6581)
- John McGiven (ORCID: https://orcid.org/0000-0002-4802-1324)
- Lydia Kilowua
- Eric Osoro (ORCID: https://orcid.org/0000-0001-5133-4279)
- Mathew Muturi (ORCID: https://orcid.org/0000-0003-2110-8099)
- John Gachohi (ORCID: https://orcid.org/0000-0001-9854-7490)
- M. Kariuki Njenga (ORCID: https://orcid.org/0000-0002-7629-7002)
- Samuel Waiguru
- Nazaria Nyaga
- Kariuki Njenga
- Ali Duba Boru
Institutions
- Washington State Department of Health (US)
- University of Nairobi (KE)
- University of Idaho (US)
- Animal and Plant Health Agency (GB)
- Jomo Kenyatta University of Agriculture and Technology (KE)
- Kenya Medical Research Institute (KE)
- University of Arusha (TZ)
- Gender Studies (CZ)
- Kenya School of Government (KE)
- Kenya AIDS Vaccine Initiative (KE)
- Ministry of Health (KE)
- Institute of Clinical Research (US)
- Centers for Disease Control and Prevention (KE)
- East African University (KE)
- Wajir County Government (KE)
- East, Central and Southern Africa Health Community (TZ)
- Washington State University (US)
- Freie Universität Berlin (DE)
Publication Details
- Journal
- International Journal of Environmental Research and Public Health
- Published
- 2025-12-12
- DOI
- https://doi.org/10.3390/ijerph22121859
- Primary Topic
- Brucella: diagnosis, epidemiology, treatment
- Type
- article
- Field-Weighted Citation Impact
- 0.00