Monday, February 04, 2019

Saudi MOH: 2 More Secondary MERS Cases In Wadi Aldwasir

Original Map Credit Wikipedia

















#13,833


Following a relatively slow 2018 for reported MERS-Cov infections (96 cases & 41 deaths globally), over the past 35 days we've seen a noticeable surge in cases in Saudi Arabia (22 cases), and a cluster of 5 cases in Oman.
In Saudi Arabia, there have been two primary epicenters of infection since the first of the year; the capital city of Riyadh (n=10), and Wadi Aldwasir (n=8), nearly 600 km to the south.
While details are scant, the 8 cases in Wadi Aldwasir are of particular interest because - in addition to two cases ascribed to having recent camel contact - with today's announcement, there now appear to be 3 distinct clusters of cases.
https://www.moh.gov.sa/en/CCC/events/national/Documents/Epiwk6-19.pdf


We still don't know the nature of the 2 secondary, community-acquired cases, or how (or even if) all of these cases are epidemiologically linked. 
We've seen clusters of MERS cases before - particularly in households or healthcare settings -  and have even seen vigorous human-to-human transmission under the right conditions (see Ziad Memish: Two MERS-CoV Hospital Super Spreading Studies).
But, thus far, community transmission of the virus has been limited, and so the virus has fallen short of producing a sustained epidemic.

A 2017 study, however, found the virus's basic reproduction number ( R0 : pronounced R-nought) was inching closer to the magic number of 1.0, which is required for an outbreak to have `legs' (see A Pandemic Risk Assessment Of MERS-CoV In Saudi Arabia).

Less than a year ago, in the WHO List Of Blueprint Priority Diseases, we saw MERS-CoV listed among the 8 disease threat in need of urgent accelerated research and development.

List of Blueprint priority diseases
(SNIP)
The second annual review occurred 6-7 February, 2018. Experts consider that given their potential to cause a public health emergency and the absence of efficacious drugs and/or vaccines, there is an urgent need for accelerated research and development for*:
  • Crimean-Congo haemorrhagic fever (CCHF)
  • Ebola virus disease and Marburg virus disease
  • Lassa fever
  • Middle East respiratory syndrome coronavirus (MERS-CoV) and Severe Acute Respiratory Syndrome (SARS)
  • Nipah and henipaviral diseases
  • Rift Valley fever (RVF)
  • Zika
  • Disease X

Although the reduction in MERS activity over the past couple of years has been welcome, it doesn't mean the threat has gone away. It is due more to improved hospital infection control, and greater public awareness of the virus, than any diminution of the virus.

While we can certainly reduce our risks by changing our behaviors, viruses are masters of adaptation and evolution.  And with nature's laboratory open 24/7, the only constant we can truly count on is change.