MERS-CoV: Where Are We Now?

Abstract

Prior to 2002, coronaviruses were known mainly for causing mild human upper respiratory tract infections (URTIs) and enteric and respiratory infections in many animals. However, their full pathogenic potential was only realised when an outbreak of severe pneumonia with a high fatality rate occurred in southern China, and they were identifi ed to be a coronavirus—severe acute respiratory syndrome (SARS). By dint of international cooperation, enhanced international and local infection control, the outbreak and the virus were contained but not without a signifi cant loss of life and lessons learnt. Outbreaks caused by coronaviruses were then quiescent, until summer 2012, when an Egyptian virologist1 identifi ed a novel coronavirus from a 49-year-old man with severe pneumonia from Jeddah, Saudi Arabia. What was unique was that the doctor had posted his fi ndings on the World Health Organization’s (WHO) ProMED-mail, a rapid and effective way of disseminating information on emerging infections and outbreaks. This sixth human coronavirus became known as the Middle East respiratory syndrome coronavirus (MERS-CoV), sequenced by the Erasmus Medical Centre and found to be a beta coronavirus with sequence homology to bat coronaviruses. Global spread was quick by dint of air travel and medical tourism; in September 2012, the same type of coronavirus, with a near identical sequence, was isolated from a patient with severe respiratory illness who had been transferred from the Middle East to London, United Kingdom. Retrospectively, an outbreak of severe pneumonia in healthcare workers in a hospital at Zarqa, Jordan, in April 2012, was shown to be likely caused by the MERS-CoV.2 With MERS-CoV, the response of the Saudi local authorities was rapid and collaborative—they invited a WHO team, consisting of expertise from abroad and Singapore, to work with them. Epidemiologically, MERS-CoV has been found in the Middle East, with cases originating from Jordan, Saudi