About Middle East Respiratory Syndrome (MERS)

What it is

Middle East Respiratory Syndrome (MERS) is a viral respiratory illness that can cause severe illness. MERS is caused by a coronavirus called Middle East respiratory syndrome coronavirus (MERS-CoV). The virus can spread from camels (dromedaries) to people through close contact. Limited person-to-person transmission is possible. MERS has caused severe respiratory disease in most reported cases, and many of those patients died.

Most MERS cases have been detected in countries in or near the Arabian Peninsula. However, several cases linked to travel have been detected in countries outside this region.

Signs and symptoms

Most people with a confirmed MERS-CoV infection have had very severe illness. MERS symptoms usually appear 5 or 6 days after a person is exposed. However, symptoms can appear as early as 2 days and up to 14 days after exposure.

Common symptoms of MERS include:

• Fever
• Cough
• Shortness of breath

Some people with MERS may also have diarrhea, nausea, or vomiting. It is also possible that someone with MERS may have only mild symptoms or no symptoms.

In most reported MERS cases, the infected person developed pneumonia. Additional complications such as kidney failure have also occurred. About 30%-40% of people reported with a MERS infection died.

Most of the people who die from MERS had at least one preexisting medical condition. Older age and certain conditions may increase the risk of getting severe complications from MERS. These include certain chronic heart, kidney, and lung diseases; cardiovascular diseases, diabetes, and certain cancers.

Who is at risk

You may be at increased risk of getting MERS if you:

• Recently (in the past 14 days) returned from travel in or near the Arabian Peninsula, and especially if you also:
  • Worked in or visited a healthcare setting.
  • Had close contact with camels (including touching or grooming).
  • Had close contact with a person who was sick with fever or respiratory symptoms.

• Had close contact in the past 14 days with someone who was sick with fever or respiratory symptoms of unknown cause after they had traveled in or near the Arabian Peninsula.
• Had close contact in the past 14 days with someone who has tested positive for MERS-CoV.

How it spreads

MERS-CoV, the virus that causes MERS, can spread through respiratory secretions, such as saliva or mucous of infected animals or people. The MERS-CoV virus is mostly found in camels (dromedaries), and close contact with camels can lead to transmission to people. People infected through contact with camels can then spread the virus to other people.

Large MERS outbreaks from person-to-person spread have occurred in healthcare facilities treating patients with MERS. The largest known outbreak of MERS outside of the Arabian Peninsula occurred in the Republic of Korea in 2015. Multiple healthcare facilities were affected by the outbreak, which was associated with a traveler returning from the Arabian Peninsula.

MERS-CoV can also spread during travel or in households through close contact (like sharing transportation, sharing a bed, or caring for someone who is sick).

Researchers continue to investigate how the virus spreads.

Prevention

There is no vaccine that can help prevent people from getting MERS.

People who travel to, in, or near the Arabian Peninsula should take precautions to lower their risk of getting MERS, including:

• Washing your hands before and after touching camels.
• Avoiding drinking raw camel milk or camel urine or eating meat (including camel meat) that has not been properly cooked.
• Avoiding close contact with camels, if you are at higher risk for severe MERS illness.

Treatment

There is no specific antiviral treatment that is recommended for MERS. People with MERS often receive supportive medical care, as needed.