The World Health Organization (WHO) yesterday reported nine new MERS-CoV (Middle East respiratory syndrome coronavirus) cases from Saudi Arabia, two of them fatal, which include a hospital cluster of seven cases in Riyadh.
The cases are Saudi Arabia's first since March, when the WHO reported four cases, which occurred between September 2024 and February 2025.
One of the patients is an adult from Hail in the west central part of the country who is older than 65 years and whose symptoms began on February 20. The patient was hospitalized and died 3 days later from his or her illness. Investigators found that the patient had indirect contact with camels.
The second patient is an adult from Riyadh who is younger than 65 and whose symptoms began on March 31. The patient was hospitalized on April 6 and died from his or her illness. Health officials found that the patient, who is not a healthcare worker, had no known contact with camels or camel products.
Four of six health workers had no symptoms
The index patient in the Riyadh hospital cluster is an older adult whose symptoms began on April 3 and was hospitalized on April 6. He or she has since recovered, and follow-up found no known exposure to camels or camel products.
Contact tracing and testing found infections in six of the hospital's healthcare workers, but only two had mild, nonspecific symptoms, with illness onsets on April 11 and April 16. All were adults younger than age 65, and all recovered from their infections.
Of the nine patients, five were men and four were women.
In its statement, the WHO said the new cases don't change its overall risk assessment for MERS-CoV, which remains moderate for both the regional and global levels. "These cases show that the virus continues to pose a threat in countries where it is circulating in dromedary camels and spilling over into the human population," the agency said.
COVID-related factors may be driving MERS declines
Reports of MERS-CoV cases to the WHO declined substantially during the COVID-19 pandemic, which the WHO said was initially likely due to the prioritization of SARS-CoV-2 surveillance. It added, however, that since the main COVID threat has eased, Saudi Arabia has ramped up testing for MERS-CoV. And since 2023, sentinel surveillance has included testing samples that are negative for flu and COVID-19.
The WHO also noted that infection protection and control measures implemented during COVID-19 circulation may have reduced onward spread of MERS-CoV. Cross-protection from COVID infection or vaccination has been theorized, but requires further investigation, the agency added.
Since the virus was first detected in humans in 2012, Saudi Arabia has now reported 2,627 lab-confirmed cases, and 946 patients (36%) died from their infections. During the height of Saudi Arabia's MERS outbreaks in 2014 and the years that followed, hospital-related clusters were a notable feature of virus spread.
