MERS-CoV Infection: Update on the Cluster of Cases in South KoreaOn May 20, 2015, South Korea notified the WHO of the first case of MERS-CoV (Middle East Respiratory Syndrome Coronavirus) diagnosed within its territory. This patient had traveled to the Arabian Peninsula from April 18 to May 4, developed initial clinical symptoms on May 11, and was diagnosed on May 20, 2015. He visited at least three healthcare facilities. As of June 1, following this index case, 14 additional cases had been confirmed and reported to the WHO by South Korean authorities, including one case exported to China. As of June 16, 2015, 162 cases had been confirmed, including 19 deaths, by South Korean health authorities (including one case exported to China). All cases have a direct or indirect epidemiological link to the index case and are all linked to a healthcare facility. The median age of cases is 56 years (range 16–87 years), and the majority of cases are men (60%). Fourteen cases have been confirmed among healthcare workers. This is the largest cluster reported outside the Arabian Peninsula (see the BHI). On June 13, 2015, recommendations were issued regarding the prevention and control of this outbreak following a joint assessment mission conducted by the WHO and the Ministry of Health. (See the recommendations).In light of the epidemiological situation in South Korea, on June 11, the InVS amended the national case definition to include as a possible case "any person who has worked at or visited a healthcare facility in South Korea and who, within the 14 days following their last contact with that facility, has exhibited signs of an acute respiratory infection, regardless of its severity. (See the new case definition)