MERS-CoV in Adults

Middle East Respiratory Syndrome coronavirus (MERS-CoV) is a beta-coronavirus first identified in Saudi Arabia in 2012. It causes severe acute respiratory infection with case fatality rate around 35%, significantly higher than COVID-19. Primary reservoir is the dromedary camel (Camelus dromedarius), with zoonotic transmission via close contact, consumption of unpasteurized camel milk, or undercooked camel products.

Human-to-human transmission has occurred predominantly in healthcare settings (nosocomial outbreaks) and within households, often associated with inadequate infection control. Incubation period averages 5 days (range 2-14). Symptoms range from mild upper respiratory illness to severe pneumonia with ARDS, septic shock, multiorgan failure, and death. Gastrointestinal symptoms (nausea, vomiting, diarrhea) are common.

Diagnosis requires RT-PCR on lower respiratory tract specimens (preferred over upper respiratory due to higher viral loads), typically with two different gene targets. Serology supports retrospective diagnosis. Management is primarily supportive: respiratory support (high-flow oxygen, NIV, mechanical ventilation, ECMO), prone positioning for ARDS, conservative fluid management, prevention of secondary bacterial infections. No specific antiviral has proven definitively effective; recombinant interferon and protease inhibitors have been used. Strict infection control with airborne and contact precautions is critical.