Middle Eastern Respiratory Syndrome (MERS)

Last Updated 11/02/2020

Authors:Keith Wille, MD, FCCP; Nirmal Sharma, MD; Robert Hyzy, MD, FCCP

About Middle Eastern Respiratory Syndrome (MERS)

Key facts about Middle Eastern Respiratory Syndrome
  • Middle Eastern respiratory syndrome (MERS) is a viral infection that can cause lung infection and kidney failure.
  • It is transmitted from camels and bats to people. It can also be transmitted by contact between people.
  • The main symptoms of MERS are fever, cough, shortness of breath, body pain, vomiting, diarrhea, and muscle pain.
  • There is no approved treatment for MERS.

MERS is a viral infection of the lungs that affects your breathing. It may also damage your kidneys and other organs.

A virus called coronavirus causes MERS. As a result, this virus is also called MERS-coronavirus (MERS-CoV). MERS-CoV belongs to the same family of viruses that cause the common cold. It causes influenza (flu)-like symptoms along with lung infection (pneumonia). MERS was first described in Saudi Arabia in 2012 in a person who went to the hospital with a lung infection and kidney failure. It was later identified in other people in the Arabian Peninsula (Egypt, Iran, Kuwait, Bahrain, Lebanon, Jordan, Oman, Qatar, the United Arab Emirates, and Yemen) and in those who traveled to Saudi Arabia. More recently, an outbreak occurred in South Korea. So far, only 2 cases of MERS have been reported in the United States. For more information about the countries affected by MERS, visit the World Health Organization’s (WHO’s) website.

How serious is MERS?

According the Centers for Disease Control and Prevention (CDC), 3 to 4 of every 10 patients with MERS die. Most patients with MERS who die had other health problems before they became infected with MERS-CoV. Some people with MERS have mild symptoms or even no symptoms at all. However, it’s important to monitor these milder cases in case the symptoms become worse.

How MERS affects your body

MERS causes a flu-like illness. Symptoms may be mild or become severe enough that you need to go to the hospital. The disease may also affect other parts of your body. This is another reason to be watched at the hospital if you have severe symptoms.

Symptoms of MERS

The most common symptoms reported with MERS include:

  • Fever with or without chills and shaking;
  • Cough, shortness of breath, and coughing up blood;
  • Sore throat;
  • Muscle pain or soreness; and
  • Vomiting, diarrhea, or belly pain.

Contact your health care provider if you have these symptoms.

What causes MERS?

MERS-CoV is mostly spread by saliva, mucus, and tears, but it’s not clear exactly how the virus spreads. You can get MERS by having close contact with people who have the MERS-CoV virus. You can also get MERS by having close contact with camels. The WHO recommends that in areas with a high risk of MERS, people should avoid being close to camels, drinking raw camel milk or urine, and eating undercooked camel meat. Symptoms may not appear right away because there’s an incubation period—that is, the time between virus exposure to the start of symptoms. For MERS-CoV, the incubation period is typically 5 or 6 days.

What are the risk factors for MERS?

You may have a higher risk of getting MERS if you:

  • Recently traveled to the Arabian Peninsula and develop respiratory symptoms within 2 weeks after you return;
  • Have other medical problems or a weak immune system;
  • Have had close contact with someone who is sick within 14 days after visiting the Arabian Peninsula, South Korea, or other countries where people have MERS;
  • Have had close contact with camels in those areas;
  • Are a health care worker treating patients with MERS and do not take precautions recommended by your facility to avoid becoming infected; or
  • Have close contact with patients with MERS.

Diagnosing MERS

Because the symptoms of MERS are similar to symptoms of the flu and other lung infections, it may be hard to know which virus is causing them. Your health care provider will first look for symptoms of respiratory illness and recent travel to the Middle East to diagnose MERS. The WHO also has a questionnaire your provider may use to determine possible causes for your illness.

If your health care provider thinks you may have MERS, he or she may order a chest X-ray, blood work, and lung and kidney tests.

When should you see your health care provider?

Contact your provider if you:

  • Develop new respiratory symptoms or fever AND
  • Have recently visited or lived in the Arabian Peninsula or any of the other countries described earlier OR
  • Have been in contact with a person with a respiratory illness who had recently traveled (within 14 days of his or her illness) to the Arabian Peninsula

Treating MERS

If you have a mild case of MERS, your health care provider will tell you to drink lots of fluids and take pain medicine for relief. If you don’t need to go to the hospital, you should stay at home and avoid contact with others to reduce the spread of the virus. If you have severe symptoms, you should go to the hospital, where you can be watched closely. You may be given oxygen therapy, antibiotics, and fluids at the hospital. You may need a breathing machine, or ventilator, to help you breathe if symptoms are severe.

If your health care provider says it’s all right for you to stay home, stay away from other people. Also, keep your personal items, like towels, bed sheets, utensils, and clothes, away from others, and wear a face mask. Cough and sneeze into your elbow, and wash your hands often with soap and water. If your symptoms get worse, tell your health care provider right away.

Preventing MERS

There is no vaccine to prevent MERS. Scientists are researching new treatments.

Other ways to help prevent MERS include:

  • Washing your hands often;
  • Avoiding touching your eyes, nose, and mouth;
  • Avoiding contact with people who have MERS;
  • Avoiding contact with camel milk or meat; and
  • Being careful about traveling to areas where people have MERS if you are 65 years of age or older; are pregnant; have heart, lung, or kidney disease; or have cancer.


According to the CDC, the United States has a low risk of MERS. Updates about vaccinations and treatment for MERS can be found on the CDC and WHO websites. If you’re outside the United States, contact health professionals in your area, and read the information on the websites listed above.

Questions to ask your health care provider

Making notes before your visit and taking along a trusted family member or friend can help you through the first appointment with your provider.

The following are some questions to help you discuss MERS with you provider:

  • Am I contagious? How much contact should I have with other people?
  • Should I take over-the-counter cough and cold products?
  • When should I seek emergency help?