Public health risk and transmission route of Middle East respiratory syndrome (MERS): MERS coronavirus in dromedary camel

Middle East respiratory syndrome corona virus (MERS-CoV) is a novel enzootic beta origin corona virus which was described in September 2012 for the first time. According to the reports of different researchers, the prevalence of MERS-CoV antibodies, during serological examination, is very high in dromedary camels of Eastern Africa and the Arabian Peninsula. However, the infection in camel is mostly asymptomatic. In contrast to the camel case, the clinical signs and symptoms of MERS-CoV infection in humans ranges from an asymptomatic or mild respiratory illness to severe pneumonia and multi-organ failure with an overall mortality rate of about 35%. Therefore, the objective of this paper was to review the public health risk, transmission routes of Middle East respiratory syndrome and to recommend the disease for further research. The identification of MERS-CoV RNA and viable virus from dromedary camels, including samples with respiratory symptoms by different studies have been detected especially in isolation of identical strains of MERS-CoV from epidemiologically linked humans and camels are the suggestive evidence for inter-transmission of the virus, primarily from camels to humans and its public health risks. Though inter-human spread within health care settings is responsible for the majority of reported MERS-CoV human cases, the virus is currently incapable of causing sustained human-to-human transmission (pandemic occurrence). Phylogenetic studies and viral sequencing results strongly suggest that MERS-CoV originated from bat ancestors after evolutionary recombination process, primarily in dromedary camels in Africa, before its exportation to the Arabian Peninsula through the camel trading routes. Currently, there is no specific drug or vaccine available for treatment and prevention of infections due to MERS-CoV in patients. The important measures to control MERS-CoV spread are strict regulation of camel movement, regular herd screening and isolation of infected camels, use of personal protective equipment by camel handlers and awareness creation on the public, especially in African pastoralists where consumption of unpasteurized camel milk is common. Therefore, urgent global epidemiological studies are required, especially in the poor camel rearing African countries to understand the transmission patterns and the human cases of MERS-CoV and also for the proper implementation of the above mentioned control measures. Key words: Dromedary camel, epidemiology, MERS-CoV, public health, respiratory syndrome.