MERS is Widespread in Saudi Arabia

Middle East Respiratory Syndrome (MERS) has infected at least 1370 individuals (including asymptomatic cases) in Saudi Arabia since 2012 (e.g. ProMED link). Since mid-February 2016, Buraidah in Al Qassim region in Saudia Arabia has been experiencing a local MERS outbreak with 23 cases reported through March 16, 2016 (link). As of April 3, 2016 there have been an additional 11 cases reported, bringing the total cases reported from Buraidah by Saudi Arabia Ministry of Health to 34.  Many of these cases are a result of nosocomial infection, but perhaps as many as eight of these cases were community acquired infections with some individuals having contact with animals. Among these 34 cases, 17 have been reported as deaths so far. (see note)

While the Buraidah MERS outbreak has raised concerns, the 34 cases from Buraidah represented about 40% of all MERS cases reported from Saudi Arabia since January 1, 2016. The majority of MERS cases since January 1, 2016, about 49 cases, have been reported from numerous other locations around Saudi Arabia as shown in the map below. 

Since January 1, 2016, human MERS cases have been reported from at least 23 populated places scattered across Saudi Arabia. The widespread geographic distribution of these cases suggests that MERS has now become endemic in Saudi Arabia.

 Note: The total cases from Buraidah include a 60 year-old male who experienced symptom onset in Hail and was treated in the Buraidah hospital where he died (Case No 3. DON March 21,  2016)

Updated Map Showing the General Locations of MERS-CoV Cases on the Arabian Peninsula (June 25, 2014)

Current map of the general geolocations of more than 700 local MERS-CoV infections on the Arabian Peninsula as of June 25, 2014. Location names are labeled in red. The area of the circle depicts the relative number of reported cases at that location. 

 

Map note: On June 3, the Saudi Arabia Ministry of Health announced more than 100 additional MERS cases that occurred between May 2013 and April 2014 (link).  No geographic information about these cases was provided by the Ministry of Health and they are not included on this map. Previous map, April 21, 2014 here.

The Saudi Arabia Ministry of Health Quietly Announces an Additional 113 Cases of MERS

Today, the Ministry of Health (MOH) officials in the Kingdom of Saudi Arabia (KSA) revised upward the number of Middle East Respiratory Syndrome (MERS) case and MERS-related deaths that have occurred in the KSA (link). As noted by Michael Coston (link), the KSA MOH added a total of 113 cases and 92 deaths to the official cumulative count from that county. The lack of any details for these additional cases or the individuals who died, precludes determining whether all of the unreported deaths are only from the previously unreported cases. In several instances in recent MOH media reports, there have been reported deaths that could not be correlated with previously reported cases because the combination of age/gender of the reported deaths from a specific location could not be associated with previously reported cases (link, link).

Through yesterday, publicly reported cases from the KSA represented about 82% of all MERS cases reported from around the world. Today, with these additional reported cases, the KSA lays claim to about 85% of all cases, not including the 20 infected cases that have been exported to at least 12 different countries. Without doubt, the nexus of worldwide MERS infections is the KSA.

This revelation of previously unreported cases by the KSA MOH ought to be disconcerting. A review of the graph associated with the report indicates that a few of these unreported cases go back as far as May of 2013. There are two possible conclusions about the delay in reporting these case by KSA MOH.  The fact that these cases are only now being publicly and officially reported could suggest that the MOH has been purposefully withholding information about these MERS cases since May of 2013.

Or, maybe the KSA MOH has been so overwhelmed by this outbreak, that they have only now been able to go back and sift through their data to find these additional cases. Either way, the announcement today, with no details or explanations, reflects negatively on the KSA MOH and their ability to track the MERS outbreak within their country.

Map Showing the General Locations of MERS-CoV Cases on the Arabian Peninsula (April 21, 2014)

Map of the general geolocations of more than 330 local MERS-CoV infections on the Arabian Peninsula as of April 21, 2014. Locations with 10 or more reported cases are labeled in black. The area of the circle depicts the relative number of reported cases at that location.  

Reported Geolocations with 10 or More MERS-CoV Cases
Geolocation	Case Count (as of April 21, 2014)
Riyadh	100
Jeddah	73
Abu Dhabi	29
Al Hofuf	26
Ash Sharqiah	17
Al Ain	15
Hafar Al-Batin	11
Madinah	11

Nosocomial Clusters of MERS-CoV Cases on the Arabian Peninsula

Since 2012, the Middle East respiratory syndrome coronavirus (MERS-CoV) has infected almost 300 people, many of them healthcare workers including nurses and doctors. Infections of health care workers and patients that take place within or are associated with a hospital or health care facility are referred to as nosocomial infections. A large number of MERS cases can be classified as nosocomial infections. For the purposes of this discussion, localized geographic clusters of MERS-CoV cases that appear to represent hospital-acquired infections are referred to as nosocomial MERS clusters. Under this definition, there has been at least 10 separate nosocomial clusters of MERS cases.

Of these clusters, only two have been reported in the literature [1,2]. The remaining nosocomial clusters are identified based on media reports, ministry of health reports, and World Health Organization reports. The quality of this data is uncertain but trends are clear and speculations can be advanced. 

The table below identifies these nosocomial clusters by location, month of outbreak for the cluster, the putative number of MERS cases within the cluster, and the number of infected health care workers reportedly associated with the cluster. The case counts include both confirmed and suspected/probable cases. The map below depicts the general locations of these clusters throughout the Arabian Peninsula. 

Table

Map

Discussion

Health care workers represent about 44% of the nosocomial cluster cases. In addition to the health care workers included in the clusters, another 21 health care workers are reported as sporadic or isolated MERS cases. The source of infection for these other health care workers is not identified, but it is likely that there have been additional nosocomial clusters that are not reported. 

Based on these data, it is clear that infection of healthcare workers with the MERS coronavirus is not a rare or random event. More than 2 years after initial hospital cluster in Jordan, health care workers continue to become infected while treating patients. We can assume that health care workers in the Arabian Peninsula region, are now familiar with, and aware of, the dangers of MERS. The fact that MERS is still infecting health care workers and possibly other patients within a hospital setting strongly suggests that MERS is highly infectious among individuals who have close contact with each other. The fact that about 25% of all reported MERS infections are doctors, nurses, and other health care workers is indicative of the infectious nature of this novel coronavirus. 

[1] Novel coronavirus infections in Jordan, April 2012: epidemiological findings from a retrospective investigation

[2] Hospital outbreak of Middle East respiratory syndrome corona­ virus