Learn About Middle Eastern Respiratory Syndrome (MERS) | American Lung Association

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Learn About Middle Eastern Respiratory Syndrome (MERS)

Middle Eastern Respiratory Syndrome, or MERS, is a viral infection that affects humans. It primarily causes infection of the lungs and affects breathing. It may also cause damage to the kidneys and other organs.

Key Facts

  • MERS is a viral disease that can cause lung infection and kidney failure in humans. It is transmitted from camels and bats to humans. It can also be transmitted by human-to-human contact.
  • The main symptoms of MERS are fevers, cough, shortness of breath, body pain, vomiting, diarrhea and muscle pain.
  • There is no current and proven treatment available for MERS. If your healthcare provider diagnoses you with MERS, you will probably be admitted to the hospital, where your breathing and other body functions will be monitored and treated. Around one-third of patients with MERS have died.

What Is MERS?

MERS is caused by a virus in the coronavirus family, and the syndrome is also called MERS-Coronavirus (MERS-CoV). This virus belongs to the same family as the common cold virus but has a completely different genetic makeup. MERS-CoV causes flu-like symptoms and lung infection (pneumonia) in humans. It was first seen in Saudi Arabia in 2012 in a person who was admitted to the hospital with lung infection and kidney failure. Thereafter, it was identified in other people who lived or traveled to the Arabian Peninsula and in those who traveled to Saudi Arabia. More recently, an outbreak was detected that affected 180 people in the Republic of Korea, including American military troops who were stationed there. So far, only two cases of MERS have been reported in the continental United States, both in healthcare workers who recently traveled to Saudi Arabia. Overall, more than 20 countries worldwide have reported cases of MERS. Details of those countries can be found on the World Health Organization website.

How Does MERS Affect Your Body?

The MERS virus, MERS-CoV, causes respiratory, or lung-related, illness. It may cause severe pneumonia and lung failure in some people, requiring admission to the hospital. It may also affect other parts of the body, causing dehydration (loss of body fluid) and kidney failure due to vomiting and diarrhea.

How Serious Is MERS?

According the Centers for Disease Control and Prevention (CDC), 3 to 4 out of every 10 patients diagnosed with MERS have died. Most of those who died also had underlying health problems before they became infected with MERS. Some patients infected with MERS-CoV have only mild symptoms or even no symptoms at all, but it is very important to monitor these milder cases closely for any worsening disease.


    This content was developed in partnership with the CHEST Foundation, the philanthropic arm of the American College of Chest Physicians.


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