human-to-human transmission: The virus does not appear to pass easily from person to person unless there is close contact, such as providing unprotected care to an infected patient. There have been clusters of cases in healthcare facilities, where human-to-human transmission appears to be more probable, especially when infection prevention and control practices are inadequate. Thus far, no sustained community transmission has been documented.
The virus appears to be circulating throughout the Arabian Peninsula, primarily in Saudi Arabia, where the majority of cases (>85%) have been reported since 2012. Several cases have been reported outside the Middle East. Most of these infections are believed to have been acquired in the Middle East, and then exported outside the region. The ongoing outbreak in the Republic of Korea is the largest outbreak outside of the Middle East, and while concerning, there is no evidence of sustained human to human transmission in the Republic of Korea. For all other exported cases, no secondary or limited secondary transmission has been reported in countries with exported cases.