Thursday, April 12, 2018

A Curious EMRO MERS-CoV Update - March


Reporting of MERS cases by the Saudi MOH has become erratic over the past few months, with missing daily reports, conflicting data between their English and Arabic reports, and (often) belated posting of information.  
The World Health Organization's last DON report (with line list) was posted on January 28th, and was current through Jan 17th.
But we also get a brief MERS-CoV summary (lacking individual case details) once each month from WHO's EMRO (Eastern Mediterranean Office), generally published around the middle of each month, covering the previous month.

During the month of February the Saudi MOH reported either 14 MERS cases  (English page total) or 16 cases (Arabic page total), while last month's February EMRO report came in higher at 23.
Between March 1st and 31st the Saudi MOH reported 16 cases (onset dates not provided), while curiously the latest EMRO report only indicates 7 new cases during the month of March.
Without onset dates, it is impossible to know exactly what is going on here.  First the March EMRO update, and then I'll return with a postscript.

MERS situation update, March 2018

At the end of March 2018, a total of 2189 laboratory-confirmed cases of Middle East respiratory syndrome (MERS), including 782 associated deaths (case–fatality rate: 35.7%) were reported globally; the majority of these cases were reported from Saudi Arabia (1814 cases, including 708 related deaths with a case–fatality rate of 39%).
In March, 7 laboratory-confirmed cases of MERS were reported in Saudi Arabia including 1 associated death. A cluster-case from a hospital in Riyadh region was reported, with 6 laboratory-confirmed cases including 3 associated deaths. The date of onset of the first case was 23 February 2018. The date of onset of the last laboratory-confirmed case from the hospital cluster was 3 March 2018; since then, there have been no new cases reported from this cluster. Further investigation on the nature of transmission is ongoing.

The demographic and epidemiological characteristics of the cases reported in March 2018 do not show any significant difference compared to cases reported during the same period from 2012 to 2017. Owing to improved infection prevention and control practices in hospitals, the number of hospital-acquired cases of MERS has dropped significantly since 2015.

The age group 50–59 years continues to be at the highest risk for acquiring infection as primary cases. The age group 30–39 years are most at risk for secondary cases. The number of deaths is higher in the age group 50–59 years for primary cases and 70–79 years for secondary cases.”

During the first ten days of March, the Saudi MOH reported 5 MERS cases from Riyadh - 3 of which were identified as nosocomial. It seems likely that many of these are belated reports from the February hospital outbreak.
Things become less clear during the second half of March, when the MOH reported 3 cases from Jeddah, 3 cases from Hufoof, 1 case from Najran, and 1 case from Madinah - plus 2 more cases from Riyadh (ttl=10).
While I can envision some plausible reasons for this discrepancy (very late MOH reporting of past cases, or perhaps they haven't reported recent cases to WHO), it would only be speculation on my part.
Hopefully we'll get a WHO DON update - with an updated case line list - so we can make some sense of all of this.
Meanwhile - despite the ongoing difficulty in getting current numbers - the good news is we've seen no signs of any sustained or efficient transmission of the MERS virus outside of health care facilities.

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