Coronaviruses (CoV) are a broad family of viruses named after the crown-like spikes on their surface. They typically cause mild to moderate upper respiratory tract disease in humans and some coronaviruses can infect animals. Mild illness caused by coronavirus includes the common cold. A severe illness caused by coronavirus is Severe Acute Respiratory Syndrome (SARS CoV).

In 2012 a novel coronavirus was identified in patients in Saudi Arabia in the Middle East. This coronavirus causes a new illness, called Middle East Respiratory Syndrome (MERS), which is a respiratory illness with an approximately 30% mortality rate.

All reported cases have been linked to countries in the Arabian Peninsula. People who have become ill either lived in the Arabian Peninsula or had recently traveled to the Arabian Peninsula, while a few had close contact with someone who had recently traveled to the Arabian Peninsula.

There has been much investigation into the host that carries the virus, but thus far, the natural reservoir remains unproven. MERS CoV has been found in camels, and testing of other animal species has failed to identify other animals that may also carry MERS CoV, so camels appear to be a likely source of infections for humans, but it is possible that other reservoirs also exist that so far have been unidentified.

Camels carrying MERS CoV may not show symptoms of illness, but may still secrete MERS CoV in their nasal and eye discharge, feces, and potentially in their milk and urine.

People visiting farms, barns, markets, or other places with animals in the Arabian peninsula should perform regular hand hygiene before and after touching animals, especially camels, and avoid any contact with sick animals.