Friday, April 18, 2014

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. 




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. 

World Map of Countries with Confirmed or Probable MERS-CoV Cases

The map below shows the countries that have reported either confirmed/suspect or imported MERS-CoV cases as of April 18, 2014.

Thursday, April 17, 2014

Increasing Number of MERS-CoV Cases in the Jeddah Outbreak

As of  April 15, the total number of MERS-CoV cases associated with the outbreak in Jeddah, Saudi Arabia was at least 30 individuals.  See:

Current Status of the MERS-CoV Outbreak in Jeddah, Saudi Arabia 

The count of MERS cases in the Jeddah outbreak is now at least 47 individuals, including one pilgrim from Malaysia (link) who died. A media report indicates that two other traveling companions from Malaysia are now exhibiting symptoms as well (link). Whether these two other individuals were infected from a common source in Jeddah or a result of human-to-human transmission remains to be reported.

Tuesday, April 15, 2014

Geographic Distribution of MERS-CoV Cases in Saudi Arabia by Region, April 15, 2014 (Map)

The Saudi Arabia Ministry of Heath published a tally of 194 MERS-CoV cases by region and governorate within the country today (machine translation link).   The breakdown by region is presented in the table below.  The general geographic location of these cases is also depicted in the map below. 


Hat tip to Giuseppe at FluTrackers

Current Status of the MERS-CoV Outbreak in Jeddah, Saudi Arabia

Since the middle of March, 2014, more than 30 individuals have been infected with MERS-CoV in the city of Jeddah in Eastern Saudi Arabia as reported by the Kingdom of Saudi Arabia (KSA) Ministry of Health.  Almost half of these cases have been officially reported in the past five days.

The official information provided by KSA on these cases is inconsistent. Onset dates after March 28, 2014, have not been reported for any the remaining 25+ cases. With the exception, of a father-son family cluster, few details are provided about the nature of the relationship between cases. Of these cases, 17 are reported as healthcare workers suggesting that many of these cases are a result of nosocomial infection. Four or five of these healthcare workers are reported as asymptomatic. 

The cases range in age from 25 to 71 years old. The mean age is 40 years old and the median age is 33 years old.  The infected individuals in Jeddah are on the average younger than previously reported cases from Saudi Arabia. The median age for all MERS-CoV cases in Saudi Arabia is about 50 with a median age 53.  

As least five of the individuals in this outbreak in Jeddah have died, although most of  the cases are still being treated. With an overall case fatality rate approaching 40% for reported MERS-CoV cases, more deaths can be expected from this outbreak. 

With little information about onset dates and the relationship between cases is it difficult to determine whether this outbreak is continuing to grow. 

Additional links: 
Hospital clusters of MERS-CoV cases, Jeddah, Saudi Arabia (map)

Is a younger cohort being infected with MERS on the Arabian Pennisula?