Risk factors for Rift Valley fever virus seropositivity in one-humped camels (Camelus dromedarius) and pastoralist knowledge and practices in Northern Nigeria

Andrew Musa Adamu; Lushakyaa Allam; Anthony K B Sackey; Alhaji Bida Nma; Philip Paul Mshelbwala; Salamatu Machunga-Mambula; Sunday Idoko Idoko; Alex Adikwu Adikwu; Wesley Daniel Nafarnda; Bello Sikiti Garba; Olajide Adewale Owolodun; Asabe Adamu Dzikwi; Emmanuel Oluwadare Balogun; Ayo Yila Simon

doi:10.1016/j.onehlt.2021.100340

Risk factors for Rift Valley fever virus seropositivity in one-humped camels (Camelus dromedarius) and pastoralist knowledge and practices in Northern Nigeria

One Health. 2021 Nov 9:13:100340. doi: 10.1016/j.onehlt.2021.100340. eCollection 2021 Dec.

Authors

Andrew Musa Adamu^{1

2}, Lushakyaa Allam³, Anthony K B Sackey², Alhaji Bida Nma¹, Philip Paul Mshelbwala⁴, Salamatu Machunga-Mambula⁵, Sunday Idoko Idoko⁶, Alex Adikwu Adikwu⁷, Wesley Daniel Nafarnda¹, Bello Sikiti Garba⁸, Olajide Adewale Owolodun⁹, Asabe Adamu Dzikwi¹⁰, Emmanuel Oluwadare Balogun¹¹, Ayo Yila Simon^{12

13}

Affiliations

¹ Department of Veterinary Public Health and Preventive Medicine, University of Abuja, Nigeria.
² Department of Veterinary Medicine, Ahmadu Bello University Zaria, Nigeria.
³ Veterinary Teaching Hospital, Ahmadu Bello University, Zaria, Nigeria.
⁴ UQ Spatial Epidemiology Laboratory, School of Veterinary Science, The University of Queensland, Australia.
⁵ Department of Microbiology, University of Abuja, Nigeria.
⁶ Department of Pathology, University of Abuja, Nigeria.
⁷ Department of Veterinary Public Health and Preventive Medicine, University of Agriculture, Makurdi, Benue State, Nigeria.
⁸ United Nations Children Fund, Yola, Nigeria.
⁹ Biotechnology Division, National Veterinary Research Institute, Vom, Nigeria.
¹⁰ Department of Veterinary Public Health and Preventive Medicine, University of Jos, Nigeria.
¹¹ Department of Biochemistry, Ahmadu Bello University, Zaria, Nigeria.
¹² Center for Blood Research and Department of Pathology and Laboratory Medicine, University of British Columbia, Vancouver, Canada.
¹³ National Centers for Animal Disease Research, Lethbridge Laboratory, Science Branch, Canadian Food Inspection Agency, Government of Canada, Lethbridge, Alberta, Canada.

Abstract

Rift Valley fever (RVF) is a complex emerging arboviral hemorrhagic disease that causes significant illness in animals and humans. Camel trade across the land borders between Nigeria and the Niger Republic occurs frequently and poses a significant risk for RVF transmission to pastoralists and traders. We carried a cross-sectional study between November 2016 and April 2017 in two northern States (Katsina and Jigawa) known for camel trade in Nigeria to investigate the seroprevalence and potential risk factors for RVFV occurrence. We collected 720 sera and administered questionnaire to pastoralists. We used the competitive enzyme-linked immunosorbent assay (c-ELISA) to determine the previous exposure to RVFV infection. We retrieved environmental information from public data sources that might explain RVFV seropositivity at the LGA level. To asses potential risk factors,we categorized LGAs with RVFV as "1" and those without a case" 0". We fitted a logistic model to the data and estimated odds ratios and 95% confidence intervals. An overall 19.9% prevalence was reported among camel herd-the highest seropositivity (33.3%) was recorded in SuleTankarkar LGA. In the multivariable model, only rain-fed croplands was significantly associated with RVFV antibodies occurrence p = 0.048 (OR = 0.87, 95% CI: 0.76-0.99). Only a minority of the respondents, 19.3% (n = 17/88), knew that RVF is zoonotic. Separation of healthy animals from the infected animals was carried out by 53.4% (47/88) pastoralists while 59.1% (52/88) pastoralists still use ethnoveterinary practices to control or mitigate disease outbreaks. Our study demonstrates the presence of RVFV antibodies among camel in Nigeria and the associated risk factors. These findings highlight the need for enhancing surveillance and control efforts and the public health education of camel pastoralists. Further investigation to unravel the zoonotic transmission potential to pastoralists and other animal species is pertinent.

Keywords: Nigeria; One-humped camels; Pastoralists; Rift Valley fever virus; Risk factors; Zoonosis.