Evidence of co-exposure with Brucella spp, Coxiella burnetii, and Rift Valley fever virus among various species of wildlife in Kenya

Francis Gakuya; James Akoko; Lillian Wambua; Richard Nyamota; Bernard Ronoh; Isaac Lekolool; Athman Mwatondo; Mathew Muturi; Collins Ouma; Daniel Nthiwa; Earl Middlebrook; Jeanne Fair; John Gachohi; Kariuki Njenga; Bernard Bett

doi:10.1371/journal.pntd.0010596

Evidence of co-exposure with Brucella spp, Coxiella burnetii, and Rift Valley fever virus among various species of wildlife in Kenya

PLoS Negl Trop Dis. 2022 Aug 8;16(8):e0010596. doi: 10.1371/journal.pntd.0010596. eCollection 2022 Aug.

Authors

Francis Gakuya¹, James Akoko^{2

3}, Lillian Wambua², Richard Nyamota², Bernard Ronoh⁴, Isaac Lekolool⁴, Athman Mwatondo^{2

5

6}, Mathew Muturi^{2

5

7}, Collins Ouma³, Daniel Nthiwa⁸, Earl Middlebrook⁹, Jeanne Fair⁹, John Gachohi^{10

11}, Kariuki Njenga¹⁰, Bernard Bett²

Affiliations

¹ Wildlife Research and Training Institute, Naivasha, Kenya.
² International Livestock Research Institute, Nairobi, Kenya.
³ Department of Biomedical Science, Maseno University, Kisumu, Kenya.
⁴ Kenya Wildlife Service, Nairobi, Kenya.
⁵ Zoonotic Disease Unit, Nairobi, Kenya.
⁶ Department of Medical Microbiology and Immunology, Faculty of Health, University of Nairobi, Kenya.
⁷ Faculty of Veterinary Medicine, Freie Universität Berlin, Germany.
⁸ Department of Biological Sciences, University of Embu, Embu, Kenya.
⁹ Los Alamos National Laboratory, New Mexico, United States of America.
¹⁰ Washington State University, Global Health Programme, Nairobi, Kenya.
¹¹ School of Public Health, Jomo Kenyatta University of Agriculture and Technology, Nairobi, Kenya.

Abstract

Background: Co-infection, especially with pathogens of dissimilar genetic makeup, may result in a more devastating impact on the host. Investigations on co-infection with neglected zoonotic pathogens in wildlife are necessary to inform appropriate prevention and control strategies to reduce disease burden in wildlife and the potential transmission of these pathogens between wildlife, livestock and humans. This study assessed co-exposure of various Kenyan wildflife species with Brucella spp, Coxiella burnetii and Rift Valley fever virus (RVFV).

Methodology: A total of 363 sera from 16 different wildlife species, most of them (92.6%) herbivores, were analysed by Enzyme-linked immunosorbent assay (ELISA) for IgG antibodies against Brucella spp, C. burnetii and RVFV. Further, 280 of these were tested by PCR to identify Brucella species.

Results: Of the 16 wildlife species tested, 15 (93.8%) were seropositive for at least one of the pathogens. Mean seropositivities were 18.9% (95% CI: 15.0-23.3) for RVFV, 13.7% (95% CI: 10.3-17.7) for Brucella spp and 9.1% (95% CI: 6.3-12.5) for C. burnetii. Buffaloes (n = 269) had higher seropositivity for Brucella spp. (17.1%, 95% CI: 13.0-21.7%) and RVFV (23.4%, 95% CI: 18.6-28.6%), while giraffes (n = 36) had the highest seropositivity for C. burnetii (44.4%, 95% CI: 27.9-61.9%). Importantly, 23 of the 93 (24.7%) animals positive for at least one pathogen were co-exposed, with 25.4% (18/71) of the positive buffaloes positive for brucellosis and RVFV. On molecular analysis, Brucella DNA was detected in 46 (19.5%, CI: 14.9-24.7) samples, with 4 (8.6%, 95% CI: 2.2-15.8) being identified as B. melitensis. The Fisher's Exact test indicated that seropositivity varied significantly within the different animal families, with Brucella (p = 0.013), C. burnetii (p = <0.001) and RVFV (p = 0.007). Location was also significantly associated (p = <0.001) with Brucella spp. and C. burnetii seropositivities.

Conclusion: Of ~20% of Kenyan wildlife that are seropositive for Brucella spp, C. burnetii and RVFV, almost 25% indicate co-infections with the three pathogens, particularly with Brucella spp and RVFV.

Publication types

Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

Animals
Animals, Wild
Brucella* / genetics
Buffaloes
Coinfection* / epidemiology
Coinfection* / veterinary
Coxiella burnetii* / genetics
Humans
Kenya / epidemiology
Rift Valley Fever*
Rift Valley fever virus* / genetics
Seroepidemiologic Studies
Zoonoses

Grants and funding

This study was sponsored by the United States Department of the Defense, Defense Threat Reduction Agency (HDTRA1-19-1-0031). The content of this paper does not necessarily reflect the position or the policy of the federal government, and no official endorsement should be inferred. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.