Flublogia has plenty of smart people who can make sense out of today's announcement 688 MERS cases (+113) and 282 deaths (+92), and I'm looking forward to posting what they conclude. In the meantime, some thoughts and questions about the implications of the chart released today.
First, if I understand the new numbers, the Saudis somehow missed a fifth of their MERS cases and a third of their MERS deaths. They started missing them in May 2013, when case numbers were under 10 per week. But misses didn't get serious until mid-March 2014, when they seem to have missed more than they caught. In hindsight, that turns into the unrecognized foreshock of the April spike. Much of that spike was also missed, especially in the second half of April.
Now, we're told, a retrospective study began last month that identified all these missed cases (and presumably led to the sacking of Dr. Memish). We don't know how it was done, only that it was "rigorous" and "more complete and accurate." Some questions:
•What is the new methodology, and how does it differ from the prior methodology?
•What were the key failures in the prior methodology, and how were they identified and corrected?
• Do we have reason to believe that the new methodology has picked up all previously missed cases and deaths, or are more surprises in store?
• Which of the missed cases, specifically, resulted in death?
•Were contacts of missed cases tracked at the time, and if not, are they being tracked now?
•In the late-April spike, were cases missed because of inadequate "surge capacity"—that is, were Saudi record-keeping systems overwhelmed, or were those cases misdiagnosed as ordinary respiratory infections?
•Given the sharp drop in cases in the second week of May, is this thanks to improved infection control or particular lessons learned from the retrospective study? Or is it basically seasonal?
•How many of the missed cases (and confirmed cases) have been in healthcare workers, in hospital settings, and in other contacts?
•Will the study lead to further steps such as seroprevalence studies?
Today's statement does set out some further steps in lab testing. They imply serious problems that will now be addressed: not enough labs capable of testing for MERS, no standard system for testing, inadequate labelling and storage of samples, and inability to transport samples to labs in timely fashion.
One final question, at least for now: Will the Saudis (and other MERS hot-zone states) finally tell WHO, CDC, and ECDC what's been going on? In detail?