Stochastic and spatio-temporal analysis of the Middle East Respiratory Syndrome outbreak in South Korea, 2015

Lee, Hyunsun

Middle East Respiratory Syndrome (MERS) is an infectious illness caused by a coronavirus that was first identified in Saudi Arabia in 2012. It resulted in a total of 2220 laboratory-confirmed cases including 790 related deaths with a case-fatality rate of 35:6% as of May 2018 according to World Health Organization (WHO). South Korea was free of MERS until 2015. The outbreak of MERS in South Korea started in May 2015 and officially ended in December 2015. The index case of the outbreak in South Korea was a 68 year-old male who developed symptoms on May 11, 2015 and sought care at two outpatient clinics and two hospitals according to WHO. As a result, he exposed MERS to a number of medical staff, hospital patients, their family members and visitors, but was not diagnosed with MERS until May 20, 2015, nine days later. The last patient, diagnosed also with lymphoma, spent 172 days in quarantine after being diagnosed with MERS on June 7, 2015 and died on November 25, 2015. The Ministry of Health and Welfare (MoHW) in South Korea declared a formal end to the MERS virus outbreak on December 23, 2015, which was the 218th day since the confirmation of the first patient. The end date was achieved after 28 days without any new infection, or twice the maximum incubation period for the MERS virus. Among 186 infected patients, 39 died of MERS, equating the fatality rate of MERS in South Korea to 20:97%. In this paper, we define a super-spreader as a laboratory-confirmed patient who infected the disease to more than five contacts.