Cross-sectional study of Middle East respiratory syndrome coronavirus in humans and dromedary camels in Diyala, Iraq

Background/aim: Middle East respiratory syndrome (MERS) is a zoonotic viral disease transmitted from dromedaries to humans. To date, more than 1500 cases of MERS have been reported and 80% of all cases have occurred in the Kingdom of Saudi Arabia (KSA). This cross-sectional study was carried out to figure out the rate of infection among humans and dromedary camels and to explore the risk factors. Materials and methods: This study was conducted in Diyala Province, Iraq for the period from August 2017 to October 2018. Human subjects included 90 participants; 34 (37.8%) were females and 56 (62.2%) were males. Additionally, 90 dromedary camels were also included, 50 (55.6%) males and 40 (44.4%) females. Serum samples from subjects were collected and tested for the presence of anti-MERS-coronavirus (CoV) immunoglobulin g (IgG). Results: The results revealed that 46 (51.1%) of human subjects were positive for anti-MERS-CoV IgG, (95% confidence interval (CI) for the prevalence rate 40.9-61.3) with a mean titer of anti-MERS-CoV IgG antibodies (Ab) of 81.2 U/mL. The anti-MERS-CoV IgG positivity rate was insignificantly higher, but the mean of anti-MERS-CoV IgG titer was significantly higher among females (p = 0.12 and p < 0.004, respectively). Furthermore, the anti-MERS-CoV IgG positivity rate and Ab titer were significantly higher among those people who visited KSA for Hajj or Umrah (p < 0.001 and p < 0.001, respectively). In camels, 81 (90.0%) were positive for anti-MERS-CoV IgG, (95% CI for the prevalence rate 82.5-94.9), with a mean titer of 99.8 U/mL. Conclusion: The MERS-CoV infection rate was high among both Iraqi humans and dromedary camels. Further confirmatory studies are needed, and setting up of national precaution program is essential.