Review on coronavirus, a middle east respiratory syndrome (MERS-CoV)

Abstract

Human coronaviruses (HCoVs) have long been considered in consequential pathogens, causing the-common cold‖ in otherwise healthy people. However, in the 21 st century, 2 highly pathogenic HCoVs-severe acute respiratory syndrome coronavirus (SARS-CoV) and Middle East respiratory syndrome coronavirus (MERS-CoV)-emerged from animal reservoirs to cause global epidemics with alarming morbidity and mortality. In December 2019, yet another pathogenic HCoV, 2019 novel coronavirus (2019-nCoV), was recognized in Wuhan, China, and has caused serious illness and death. The ultimate cope and effect of this outbreak is unclear at present as the situation is rapidly evolving. Middle East respiratory syndrome coronavirus (MERS-CoV) is zoonotic diseases causing severe respiratory illness emerged in 2012 in Saudi Arabia. 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. The prevalence of MERS-CoV antibodies, the identification of MERS-CoV RNA and viable virus from dromedary camels of Eastern Africa and the Arabian Peninsula are the suggestive evidence for inter-transmission of the virus, primarily from camels to humans and its public health risks. 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%. 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). Currently, there is no specific drug or vaccine available for treatment and prevention of MERS-CoV. 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 where consumption of unpasteurized camel milk is common. Therefore, urgent global epidemiological studies are required, to understand the transmission patterns and the human cases of MERS-CoV and also for the proper implementation of the above-mentioned control measures.