Middle East Respiratory Syndrome (MERS) is a severe respiratory illness that mainly involves the upper respiratory tract. It causes fever, coughing, and shortness of breath. About 30% of people who have gotten this illness have died. Some people only have mild symptoms.
MERS is caused by the Middle East Respiratory Syndrome Coronavirus (MERS-CoV). It was first reported in Saudi Arabia in 2012 and then spread to many countries. Most cases were spread from people who traveled to the Middle Eastern countries
To date, there have only been 2 cases of MERS in the United States. They were in people traveling to the United States from Saudi Arabia and diagnosed in 2014. The virus poses a very low risk to people in the United States.
How MERS Spreads
No one knows exactly where the MERS virus comes from. It has also been found in camels and in one bat. While it is believed to come from animals, that is still unclear.
The virus can spread between people in close contact. This includes health care workers who care for people with MERS.
The incubation period of this virus is not precisely known. This is the amount of time between when a person is exposed to the virus and when symptoms occur. In the first cases, the average incubation period seemed to be 5 days, but there are cases that occurred up to 14 days after exposure.
The most common symptoms have included fever, chills, and cough. Less common symptoms include coughing up blood, diarrhea, and vomiting. However, these symptoms can also occur in a number of other conditions.
All people with MERS had an abnormal chest x-ray.
Right now, there is no vaccine for MERS and no specific treatment. Supportive care is given.
Steps to Help Prevent MERS
If you plan to travel to one of the countries where MERS is present, the Centers for Disease Control Prevention (CDC) advises taking the following steps to prevent illness.
- Wash your hands often with soap and water for 20 seconds. Help young children do the same. If soap and water are not available, use an alcohol-based hand sanitizer.
- Cover your nose and mouth with a tissue when you cough or sneeze then throw the tissue in the trash.
- Avoid touching your eyes, nose, and mouth with unwashed hands.
- Avoid close contact, such as kissing, sharing cups, or sharing eating utensils, with sick people.
- Clean and disinfect frequently touched surfaces, such as toys and doorknobs.
- If you come in contact with animals, such as camels, wash your hands thoroughly afterward. It has been reported that some camels carry the MERS virus.
For more information about MERS, go to the CDC website: www.cdc.gov/coronavirus/mers/index.html.
Middle East Respiratory Syndrome Coronavirus; MERS-CoV; Novel coronavirus; nCoV
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McIntosh K, Perlman S. Coronaviruses, including severe acute respiratory syndrome (SARS) and Middle East Respiratory Syndrome (MERS). In: Bennett JE, Dolin R, Blaser MJ, eds. Mandell, Douglas, and Bennett's Principles and Practice of Infectious Diseases, Updated Edition. 8th ed. Philadelphia, PA: Elsevier Saunders; 2015:chap 157.
World Health Organization website. Middle East respiratory syndrome coronavirus (MERS-CoV). www.who.int/emergencies/mers-cov/en. Accessed April 24, 2018.
Review Date 2/24/2018
Updated by: Jatin M. Vyas, MD, PhD, Assistant Professor in Medicine, Harvard Medical School; Assistant in Medicine, Division of Infectious Disease, Department of Medicine, Massachusetts General Hospital, Boston, MA. Also reviewed by David Zieve, MD, MHA, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.