ORIGINAL ARTICLE Open Access Epidemiologic features of the first MERS outbreak in Korea: focus on Pyeongtaek St. Mary’s Hospital

OBJECTIVES: This study investigated the epidemiologic features of the confirmed cases of Middle East Respi-ratory Syndrome (MERS) in Pyeongtaek St. Mary’s Hospital, where the outbreak first began, in order to iden-tify lessons relevant for the prevention and control of future outbreaks. METHODS: The patients ’ clinical symptoms and test results were collected from their medical records. The caregivers of patients were identified by phone calls. RESULTS: After patient zero (case #1) was admitted to Pyeongtaek St. Mary’s Hospital (May 15-May 17), an outbreak occurred, with 36 cases between May 18 and June 4, 2015. Six patients died (fatality rate, 16.7%). Twenty-six cases occurred in the first-generation, and 10 in the second-generation. The median incubation pe-riod was five days, while the median period from symptom onset to death was 12.5 days. While the total at-tack rate was 3.9%, the attack rate among inpatients was 7.6%, and the inpatients on the eighth floor, where patient zero was hospitalized, had an 18.6 % attack rate. In contrast, caregivers and medical staff showed at-tack rates of 3.3 % and 1.1%, respectively