Seroprevalence of Middle East Respiratory Syndrome Corona Virus in dromedaries and their traders in upper Egypt

Amal Sm Sayed,Safaa S Malek,Mostafa Fn Abushahba

doi:10.3855/jidc.10862

Abstract

Camel trade in Egypt depends mainly on importation. Seemingly healthy imported camels are responsible for the ingress of serious diseases into Egypt. A striking example of this concerning public health globally is the Middle East respiratory coronavirus (MERS-CoV) which causes case fatalities of over 34%. Here, we determined the seroepidemiological situation of the MERS-CoV in imported camels and their traders in Upper Egypt. Sera of sixty-three dromedaries and twenty-eight camel traders were recruited (January 2015-December 2016). The age, gender, and sampling locality of each sampled camel and human were obtained. Semi-quantitative anti-MERS-CoV IgG ELISAs which utilize the purified spike protein domain S1 antigen of MERS coronavirus (MERS-CoV S1) were used to detect specific IgG antibodies against the virus. The data showed that 58.73% of imported camels and 25% of traders had antibodies specific to MERS-CoV. Interestingly, like seroreactive camels, all seropositive humans were apparently healthy without any history of developing severe respiratory disease in the 14 days prior to sampling. Having specific antibodies among the examined camel sera was significantly different (P < 0.0001) in relation to various sampling localities, gender and age groups. In contrast, the seropositivity rate of MERS-CoV IgG in humans did not differ significantly by any of the studied factors. The current study provides the first serological evidence of occupational exposure of humans to MERS-CoV in Africa. Additionally, it reports that imported camels could be implicated in introducing MERS-CoV into Egypt. Accordingly, application of strict control measures to camel importation is a priority.

Highlights

Camel trade in Egypt depends mainly on importation
Occupational MERS-CoV zoonosis from infected dromedaries was extensively documented in the Arabian Peninsula [21,22,23,24,25,26] whereas, no zoonotic MERS-CoV cases have been reported to date in Africa [27]
There was a significant relationship between the species and the likelihood of having antibodies against the virus (P = 0.0034) and camels found to be at a greater exposure rate (Odds ratio, Odds ratios (OR) = 4.27) compared to humans in contact with camels (OR = 0.23) (Table 1)

Summary

Introduction

Camel trade in Egypt depends mainly on importation. Seemingly healthy imported camels are responsible for the ingress of serious diseases into Egypt. Conclusions: The current study provides the first serological evidence of occupational exposure of humans to MERS-CoV in Africa. It reports that imported camels could be implicated in introducing MERS-CoV into Egypt. The single-humped, Arabian dromedary camel (Camelus dromedarius) has been strongly implicated as the MERS-CoV reservoir in which the disease is either asymptomatic or manifested as mild respiratory infection [3]. Recent reports indicating the genetic identity between the human and camel isolates of MERS-CoV have provided strong evidence that dromedaries are potential sources of human infection [13,17,18,19,20,21]. In 2013, human-to-human transmission of the virus was documented among healthcare workers in Saudi Arabia [29]

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Results

Discussion

Conclusion