On May 12, 2025, the the Ministry of Health (MoH) of the Kingdom of Saudi Arabia (KSA) reported nine cases of Middle East respiratory syndrome coronavirus (MERS-CoV) infection. Two of these cases died.

Among the nine cases, a cluster of seven cases were identified in Riyadh, including six health and care workers who acquired the infection from caring for a single infected patient. The cluster was identified through contact tracing and subsequent testing of all contacts, with four of the six health and care workers being asymptomatic and two showing only mild, nonspecific signs.

Middle East respiratory syndrome (MERS) is a respiratory illness caused by a coronavirus (MERS-CoV). The fatality rate among confirmed cases is around 36%, though this may be an overestimate since milder cases often go undetected.

Humans contract MERS-CoV through direct or indirect contact with dromedary camels, the virus’s natural host and zoonotic reservoir. Human-to-human transmission occurs via infectious respiratory particles mainly at close distances and also through contact transmission, it has mainly occurred in close-contact situations, particularly in health-care settings. Outside these environments, there has been limited documented human-to-human transmission to date. 

No vaccine or specific treatment is currently available, although several MERS-CoV-specific vaccines and therapeutics are in development. Treatment remains supportive, focusing on managing symptoms based on the severity of the illness.