With the the start of the Holy month of Ramadan just over 10 days away (this year, May 26th-June 25th) - a time when hundreds of thousands of religious pilgrims from around the world travel to Saudi Arabia to perform Umrah - we are understandably on watch for any signs of increased MERS activity.
MERS case reports been only moderate this year, with a steady trickle of community acquired cases (roughly 15 a month), punctuated by occasional small hospital clusters. We've not seen any truly large nosocomial outbreaks (100+ cases) since the summer of 2015.Over the weekend the Saudi MOH has reported four new cases, 3 of which are hospital acquired. Of those, two are asymptomatic.
The three reports follow:
Prior to 2016, the assumption was (based on very limited contact testing by the Saudis), that only about 10% of MERS cases were asymptomatic (or mildly ill). Recent testing has suggested that number may be low.
Following unusually candid (and public) criticism of the Saudi's lack of testing and reporting of asymptomatic cases (see Sept 2015 WHO Statement On The 10th Meeting Of the IHR Emergency Committee On MERS), we've seen a significant jump in the number of asymptomatic cases reported.
Since contact tracing and testing is much easier to coordinate in a hospital environment, it isn't surprising that nosocomial outbreaks have revealed a higher rate of asymptomatic infection.Unknown are how many undetected mild and/or asymptomatic cases there are in the community, and how much of a role - if any - they may play in the spread of the virus.