Middle East Respiratory Syndrome Coronavirus Outbreak in the Republic of Korea, 2015

Abstract

ObjectivesThe outbreak of Middle East respiratory syndrome coronavirus (MERS-CoV) infection in the Republic of Korea started from the index case who developed fever after returning from the Middle East. He infected 26 cases in Hospital C, and consecutive nosocomial transmission proceeded throughout the nation. We provide an epidemiologic description of the outbreak, as of July 2015.MethodsEpidemiological research was performed by direct interview of the confirmed patients and reviewing medical records. We also analyzed the incubation period, serial interval, the characteristics of superspreaders, and factors associated with mortality. Full genome sequence was obtained from sputum specimens of the index patient.ResultsA total of 186 confirmed patients with MERS-CoV infection across 16 hospitals were identified in the Republic of Korea. Some 44.1% of the cases were patients exposed in hospitals, 32.8% were caregivers, and 13.4% were healthcare personnel. The most common presenting symptom was fever and chills. The estimated incubation period was 6.83 days and the serial interval was 12.5 days. A total of 83.2% of the transmission events were epidemiologically linked to five superspreaders, all of whom had pneumonia at presentation and contacted hundreds of people. Older age [odds ratio (OR) = 4.86, 95% confidence interval (CI) 1.90–12.45] and underlying respiratory disease (OR = 4.90, 95% CI 1.64–14.65) were significantly associated with mortality. Phylogenetic analysis showed that the MERS-CoV of the index case clustered closest with a recent virus from Riyadh, Saudi Arabia.ConclusionA single imported MERS-CoV infection case imposed a huge threat to public health and safety. This highlights the importance of robust preparedness and optimal infection prevention control. The lessons learned from the current outbreak will contribute to more up-to-date guidelines and global health security.

Clinical and Epidemiologic Characteristics of Spreaders of Middle East Respiratory Syndrome Coronavirus during the 2015 Outbreak in Korea

“…We reviewed the publically available epidemiologic database compiled by the Korea Centers for Disease Control and Prevention (3) and clinical database compiled by the Korean Society of Infectious Diseases (KSID) (10). Infectious disease specialists who had cared for MERS patients completed case record form which KSID developed.…”

“…The outbreak was amplified by super-spreading events at hospitals and movement of patients between hospitals. Spreading events occurred until late June 2015, more than a month after the index patient was identified, resulting in a total of 186 patients with MERS-CoV infection and 38 fatalities, which is the largest outbreak outside the Arabian Peninsula (34). During the outbreak, almost 17,000 individuals at epidemiologic risk were quarantined, and all laboratory-confirmed cases were admitted to hospitals for isolation.…”

Differential Cell Count and CRP Level in Blood as Predictors for Middle East Respiratory Syndrome Coronavirus Infection in Acute Febrile Patients during Nosocomial Outbreak

“…The Republic of Korea experienced the largest outbreak of Middle East respiratory syndrome coronavirus (MERS-CoV) infection outside the Arabian Peninsula in 2015, including 186 laboratory-confirmed cases (12). The reported data suggest that MERS-CoV is most likely to be transmitted as healthcare-associated infections and poses a serious risk for nosocomial outbreak (123456).…”

“…The reported data suggest that MERS-CoV is most likely to be transmitted as healthcare-associated infections and poses a serious risk for nosocomial outbreak (123456). During the nosocomial outbreak of MERS, many patients were identified and quarantined by means of active surveillance.…”

“…The initial symptoms in the most MERS cases were nonspecific fever, usually accompanied by cough, sore throat, myalgia, headache, and diarrhea. However, these symptoms are also common in other viral infections (13578). Common laboratory findings of MERS were also similar to those of SARS and other respiratory viral infections, and lymphopenia was observed generally among MERS patients (34812).…”