Middle East respiratory syndrome (MERS) is a mild to severe upper respiratory tract infection caused by a coronavirus that spreads from animals to humans (usually camels), but also amongst humans. Middle East respiratory syndrome is mainly found in Saudi Arabia and other Middle-Eastern countries.

Symptoms of Middle Eastern respiratory syndrome usually appear anywhere from 5 to 6 days after exposure but can occur between 2 to 14 days. The symptoms can be mild to severe. Individuals with mild infections may experience no symptoms or cold-like symptoms. The main symptoms of Middle Eastern respiratory syndrome include fever, coughing, and shortness of breath, while some individuals may also cough up blood or experience nausea and/or vomiting or diarrhea. Severe infections may develop in immunocompromised individuals, causing pneumonia or kidney failure. Middle Eastern respiratory syndrome has a death rate of around 30%.

Treatment for Middle Eastern respiratory syndrome involves supportive care. There is currently no vaccine or antiviral treatment available.