Middle East Respiratory Syndrome Coronavirus- Sero-prevalence in Camels, Knowledge of Camel Handlers, Hygiene and Slaughter Practices at Athi-River Slaughterhouse, Machakos County, Kenya

Abstract

The dromedary camel is a reservoir and source for zoonotic transmission of Middle East Respiratory syndrome coronavirus with similarity of camel and human-derived sequences. Middle East Respiratory Syndrome, first identified in 2012 is caused by the MERS coronavirus (MERS-CoV). Between 2012 and June 2018, there were over 2200 confirmed human cases. There is possible occupational exposure among camel handlers with slaughter-house workers being at high risk. Affected camels are asymptomatic with prevalence being higher in mature camels. Sero-prevalence of MERS-CoV in a study carried out in 2012 in Kenya was reported at 29.5%. The objectives of this study were to determine the sero-prevalence of MERS-CoV in camels at the Athi-river slaughterhouse, determine knowledge regarding MERS among camel handlers and identify bio-safety practices during slaughter. The study was cross-sectional; the study used systematic random sampling to select camels from which 372 blood samples were collected. An indirect immune-fluorescent Enzyme linked immune-sorbent assay (IgG ELISA) was performed to detect anti-MERS-CoV antibodies. Structured questionnaires were administered to collect data on knowledge of MERS among camel handlers. A check list was used to collect data on slaughter practices. Proportions were calculated and associations between anti-MERS-CoV antibody sero-positivity and age group, sex, and origin of camels were assessed using Chi-square tests. Anti-MERS-CoV antibody sero-prevalence obtained overall was 77.4% (95% CI: 72.83-81.57). Prevalence in camels aged < 5 years (n=4) was 50%, 81.6% in those aged ≥ 5–8 years (n=98), 76.1% in those >8-11 years (n=255), and 80% in those over 11 years (n=15). Prevalence in males camels (n=176) was 76% (95% CI 74-86%) while in females (n=196), it was 78% (95% CI 78-88%). Based on origin of camels: Northern Kenya (77.5%, 95% CI: 70.4-83.57), coastal region (77.7%, 95% CI: 71.2-83.4), and Rift Valley region (70%, 95% CI: 34.8-93.3). There was no statistical difference in prevalence based on age group (ꭓ2 (2, N=372) =0.835 p=0.659), sex (ꭓ2 (1, N=372) =0.195 p=0.659), or origin of the camels (ꭓ2 (2, N=372) =0.326 p=0.851). Among 22 persons (5 herders and 17 slaughter-house workers), 18 had worked with camels for over 3 years. Sixteen (73%) were unaware of MERS-CoV. All reported washing hands after handling camels while 3/22 drank raw camel milk. Nineteen were aware of zoonotic diseases and common ways of transmission being: eating improperly cooked meat (90%), drinking raw milk (68%), and slaughter processes (50%). On bio-safety measures: - among 17 slaughter-house workers, 82% wore gumboots and 65% wore overalls/dustcoats with none using gloves or facemasks. All handlers interviewed lacked information on interaction of camels across borders but reported frequent interaction during grazing and transportation. High MERS-CoV sero-prevalence observed was consistent with other studies in Africa among adult camels. Increase in sero-prevalence over time could be due to continued exposure to the virus. Workers at this slaughter-house lacked knowledge about MERS-CoV but were aware of zoonotic diseases and their transmission. This could serve as an entry point to create awareness on MERS. Use of personal protective clothing to prevent direct contact with discharges and aerosols was lacking. There is need to enhance hygiene and bio-safety practices among camel handlers mainly slaughter-house workers to reduce opportunities for potential virus transmission. These results will contribute towards an effective integrated human-animal MERS-CoV control strategy in Kenya.