MERS coronavirus: an emerging zoonotic virus

Abstract

Middle East respiratory syndrome coronavirus (MERS-CoV) is an emerging virus that was first reported in humans in June 2012 [1]. To date, MERS-CoV continues to infect humans with a fatality rate of ~35%. At least 27 countries have reported human infections with MERS-CoV (https://www.who.int/emergencies/mers-cov/en/). MERS-CoV is a zoonotic virus. Like severe acute respiratory syndrome coronavirus (SARS-CoV), MERS-CoV is believed to have originated from bats [2,3]. However, whereas the bat-to-human transmission of SARS-CoV was likely mediated by palm civets as intermediate hosts, humans likely acquired MERS-CoV from dromedary camels [4,5,6]. Human-to-human transmission of MERS-CoV does occur, but it is limited mostly to health care environments [7,8]. Moreover, whereas SARS-CoV recognizes angiotensin-converting enzyme 2 (ACE2) as a cellular receptor [9,10], MERS-CoV uses dipeptidyl peptidase 4 (DPP4) to enter target cells [11,12]. Currently, no vaccines or antiviral therapeutics have been approved for the prevention or treatment of MERS-CoV infection, although a number of them have been developed preclinically and/or tested clinically [13,14,15,16].