Between April 1 and May 23, 2013, a total of 23 confirmed cases of human infection with MERS-CoV were identified in the eastern province of Saudi Arabia (Fig. S1 in the Supplementary Appendix). All confirmed cases and 11 probable cases were part of a single outbreak involving four health care facilities (Figure 1)...
The paper provides dramatic evidence for similarities between the spread of MERS-CoV and SARS-CoV in 2003, and raises serious concerns about potential infections and spread linked to Umrah associated with Ramadan beginning July 9, as well as the Hajj in KSA in October.
Thus, this cluster helps explain why the case fatality rate is 82% in KSA. The biased testing of hospital cases and limited detection of milder cases has produced a CFR that is markedly higher than the Jordan ICU outbreak or the onward transmission cases in England, France, Tunisia, and Italy.
Similarly, the multiple transmission chains support sustained transmission, which WHO describes as "seemingly sporadic".