Seroprevalence of four zoonotic viral diseases in camels in Qatar.

BACKGROUND: Understanding the dynamics of zoonotic diseases is integral to the One Health approach, as it guides strategies to mitigate the impact of infections on both animal and human health. In Qatar, the circulation of many zoonotic viral infections among animals remains unknown.

AIM: This study aimed to investigate the seroprevalence of four zoonotic viral diseases in camels in Qatar: The Middle East respiratory syndrome coronavirus (MERS-CoV), in addition to three arboviruses (arthropod-borne viruses): [West Nile virus (WNV), Crimean-Congo hemorrhagic fever virus (CCHFV), and Rift Valley fever virus (RVFV)].

METHODS: A total of 186 camel samples were collected from 23 farms at six municipalities in Qatar between 2019 and 2021. Specific anti-virus IgG or IgM antibodies were detected using commercial enzyme-linked immunosorbent assay (ELISA) kits.

RESULTS: Overall, we found a high seroprevalence of MERS-CoV IgG in camels (95.1 %), followed by CCHFV IgG (56 %) and WNV IgG (23.3 %). On the other hand, the seropositivity of anti-RVFV IgG was 1.7 %, and none of the tested samples exhibited RVFV-reactive IgM antibodies. Moreover, 97 (52.2 %) camel samples tested positive for at least MERS-CoV- and CCHFV-reactive antibodies. Seroprevalences were comparable irrespective of the animals' sex. Although MERS-CoV exposure was high in all age groups (>92 %), a statistically significant difference in the anti-MERS-CoV IgG ELISA OD values was observed between samples collected from camels aged 10 years or above compared to those below the age of 5 years (p = 0.018).

CONCLUSION: Our study provided evidence of a relatively high ratio of exposure to MERS-CoV, CCHFV, and WNV in camels in Qatar. To better understand these zoonotic viral diseases, additional studies involving larger animal populations, investigating vector dynamics, and monitoring livestock movements in and out of the country are imperative.