Middle East respiratory syndrome (MERS)

Middle East respiratory syndrome (MERS) should be considered when a severe respiratory illness occurs in the 2 weeks following residence in or travel to the Middle East or areas of outbreak, and/or close contact with infected individuals.

The majority of cases are the result of human-to-human transmission, with peaks of confirmed cases occurring during nosocomial outbreaks. Clinical presentation ranges from asymptomatic to severe, rapidly progressive, potentially fatal pneumonia.

Clues on routine laboratory testing include leukopenia, lymphopenia, thrombocytopenia, and evidence of acute kidney injury. Confirmation of infection requires specialized laboratory testing including real-time reverse transcription polymerase chain reaction (RT-qPCR) on respiratory samples and serum.

Treatment is supportive; however, several promising virus-specific therapies are under investigation. Vaccines are undergoing trials.

Epidemic potential is considered low at present unless the virus mutates.

MERS is an acute viral respiratory tract infection caused by the novel betacoronavirus MERS coronavirus (MERS-CoV). It was first identified in Saudi Arabia in 2012. Cases have been limited to the Arabian Peninsula and its surrounding countries, and to travelers from the Middle East or their contacts. The clinical spectrum of infection varies from no symptoms or mild respiratory symptoms to severe, rapidly progressive pneumonia, acute respiratory distress syndrome, septic shock, or multiorgan failure resulting in death.