Middle East respiratory syndrome coronavirus (MERS-CoV): A cluster analysis with implications for global management of suspected cases

Memish, Ziad A.; Al-Tawfiq, Jaffar A.; Alhakeem, Rafat F.; Assiri, Abdullah; Alharby, Khalid D.; Almahallawi, Maher S.; Alkhallawi, Mohammed

Since the initial description of the Middle East respiratory syndrome (MERS) in September 2012, a total of 1038 cases of MERS-CoV including 460 deaths have been reported from Saudi Arabia. From August 24, 2013 to September 3, 2013, a total of 397 patients and contacts were tested for MERS-CoV. Of those tested, there were 18 (4.5%) MERS-CoV cases reported in Al-Madinah al-Munawwarah with one large cluster. In this report, we describe the outcome, epidemiology and clinical characteristics of this cluster of which 4 cases involved healthcare workers. Fourteen cases appeared to be linked to one cluster involving healthcare workers (HCWs), family and patient contacts. Of the 18 cases, five (including 2 HCWs) were community acquired, two were household contacts, and 11 were healthcare associated (including 4 HCWs). All except 4 cases were symptomatic and the case fatality rate was 39% (7 of 18). The outbreak resulted in human to human transmission of an estimated 6 cases. Contact screening showed positive test in 1 of 56 (1.8%) household contacts, and 3 of 250 (1.2%) HCWs.