Increase in Middle East Respiratory Syndrome-Coronavirus Cases in Saudi Arabia Linked to Hospital Outbreak With Continued Circulation of Recombinant Virus, July 1–August 31, 2015

Assiri, Abdullah M.; Biggs, Holly M.; Abedi, Glen R.; Lu, Xiaoyan; Bin Saeed, Abdulaziz; Abdalla, Osman; Mohammed, Mutaz; Al-Abdely, Hail M.; Algarni, Homoud S.; Alhakeem, Raafat F.; Almasri, Malak M.; Alsharef, Ali A.; Nooh, Randa; Erdman, Dean D.; Gerber, Susan I.; Watson, John T.

During July-August 2015, the increase in reported cases of MERS from SA was largely attributable to an outbreak at a single healthcare facility in Riyadh, with approximately 80% of cases linked to Hospital A. Overall, 129 (90%) of 143 cases reported in July and August were exposed to a healthcare setting or had close contact with a known MERS-CoV case during the exposure period. Sporadic cases were relatively uncommon. The case fatality rate of 43% during July-August 2015 was similar to the overall MERS-CoV case fatality rate of 42% reported in SA since 2012 [8] . Other characteristics of cases, such as male predominance, median age, and a high prevalence of medical comorbidities, particularly diabetes, are consistent with what has been described from earlier outbreaks [2, 9] . Our findings demonstrate that transmission of MERS-CoV continues to be predominantly linked to healthcare exposure and, to a lesser extent, household exposure to close contacts [2, 3] .