The Same Middle East Respiratory Syndrome-Coronavirus (MERS-CoV) yet Different Outbreak Patterns and Public Health Impacts on the Far East Expert Opinion from the Rapid Response Team of the Republic of Korea

Second, certain super-spreading events (SSEs) played an important role for more than 80% of the patients. The basic reproductive number, R 0 , is defined as the mean number of infections caused by an infected individual in a susceptible population. R 0 can induce considerable individual variation in infectiousness, as highlighted during the severe acute respiratory syndrome (SARS) pandemic [5] . This value is a measure of the potential of a disease to spread to susceptible populations in the absence of control measures. In addition, SSEs serve as appropriate predictive correlates of higher infectiousness. The 20/80 rule states that 20% of individuals within any given population are responsible for 80% of the transmission of a potential pathogen [6] . Super-spreaders are defined as infected individuals who cause a disproportionately large number of secondary infections, as compared with the majority of infected individuals who cause few (or no) infections [6] . SSEs are produced by multiple factors, including co-infection with another pathogen, immune suppression, changes in airflow dynamics, delayed hospital admission, misdiagnosis, and public health challenges, and represent important facets of infectious disease management and pandemic preparedness plans [6] . There were the five SSEs in this outbreak. For example, the index case infected 28 people, and another case infected 84 people. An SSE is usually characterized with bilateral pneumonia of the infecting patient, which could result in easier transmission owing to more viral shedding either by direct or indirect contact via droplets [7] . Delayed diagnosis and crowded hospital rooms, attributed to both cultural and socioeconomic reasons, have also produced SSEs. The most common type of hospital room in Korea consists of multiple beds in which more than 10 people including family members, Third, environmental contamination, also referred to as a fomite-mediated contact transmission source, likely contributed to some cases. PCR testing yielded positive results using samples from the patients' rooms, emergency room (ER), X-ray rooms, and restroom environments, in which both the index and the other patient causing an SSE had stayed or been in contact. This was a lesson for the RRT regarding the importance of enforced environmental decontamination and cleaning to control the MERS-CoV outbreak.