Serological identification of MERS-CoV in camels of Wasit province, Iraq

Abstract

Background: Since the first human case of Middle East Respiratory Syndrome (MERS) caused by Coronavirus (MERS- CoV) in 2012, several evidence bases have shown one-humped camels as the main reservoir host, from which infection is transmitted to humans.

Aim: Serological investigation of MERS in dromedary camels in Wasit province (Iraq), detection severity of infection, and association to some risk factors.

Methods: A total of 455 dromedary camels were selected randomly from two main districts in Wasit province, Iraq, during January and April (2023). Sera of all study camels were examined by enzyme-linked immunosorbent assay (ELISA), and titers of positive study animals were categorized according to their severity.

Results: Serological testing  yielded 37.58% positive animals for MERS infection. According to the severity of positive ODs (titer), a total of 53.22%,  30.99%, 12.28%, and 3.51% showed mild, moderate, strong, and very strong infections, respectively. Regarding risk  factors, significant elevation in seropositivity was seen in camels of >3–6 and >6 years old and reduced in camels of £3  years old with an elevated risk of MERS with increased age. Regionally, seropositivity and relative risk were increased in  the camels of Shaykh Sa’d when compared with Al-Numaniyah. Regarding sex, no significant variation was detected  between seropositive females and males; however, male camels appeared at higher risk than females. Association  between the severity of MERS infection and risk factors revealed that there was a significant increase in mild and  moderate infections in female camels of >6 years old; whereas strong and very strong infections were seen in male  camels of ³3–6 years old. Mild and very strong infections were recorded in Shaykh Sa’d; while moderate and strong  infections in Al-Numaniyah.

Conclusion: The study indicated a longstanding existence of MERS-CoV in camels of Wasit  province; therefore, recent infections or active viral excretion are required for confirmation by molecular approaches.