Middle East Respiratory Syndrome (MERS)

What is MERS?

Middle East respiratory syndrome (MERS) is a severe respiratory illness caused by a type of coronavirus. It was first reported in Saudi Arabia in 2012.

What are coronaviruses?

Coronaviruses are a group of viruses that usually infect birds and mammals. Sometimes these viruses change and spread to humans.

Scientists first described coronaviruses in the mid-1960s. Since then, they have identified seven strains of coronavirus that make humans sick. Four strains cause only mild or moderate cold-like symptoms.

Three coronavirus strains cause more serious illness:

• Severe acute respiratory syndrome coronavirus (SARS-CoV), identified in 2003.
• Middle East respiratory syndrome coronavirus (MERS-CoV), identified in 2012.
• SARS-CoV-2, the virus that causes coronavirus disease 2019 (COVID-19).

How common is MERS?

As of January 2020, the World Health Organization has recorded 2,519 cases of MERS since it emerged in 2012. A total of 27 countries have reported cases, of which 80% have occurred in Saudi Arabia. All cases have been linked to travel or residence to countries in or around the Arabian peninsula such as Iraq, Iran, Israel, Saudi Arabia and Syria.

The U.S. has seen only two cases of MERS. Both were healthcare workers who had recently returned from Saudi Arabia.

Who is at risk of MERS?

People are at risk of MERS if they:

• Recently traveled to the Arabian peninsula.
• Had close contact with someone who traveled to the Arabian peninsula and became ill.
• Had close contact with someone with a confirmed MERS-CoV infection.
• Are a healthcare worker who had close contact with a patient with MERS and did not follow infection control measures.
• Had direct contact with camels or consumed raw camel meat or milk.

Where did MERS come from?

Researchers think that MERS, SARS and COVID-19 originated in bats, then spread to other animals before jumping to humans.

• MERS-CoV spread to camels and then to humans.
• SARS-CoV reached humans through civets (small mammals found in Africa and Asia).
• Scientists don’t yet know what type of animal spread COVID-19 to people.

How is MERS transmitted?

Like some other infectious diseases, MERS-CoV is present in your respiratory tract. You transmit it through coughing.

MERS is contagious. However, it does not spread quickly, unlike COVID-19, which spread rapidly around the world. MERS transmission requires close contact, such as between family members or in a healthcare setting. Health officials have not observed community-wide spread of MERS.

You can also get MERS from camels. In Saudi Arabia and surrounding countries, camels have strains of MERS that match human strains. This suggests active transmission of MERS from camels to people.

What are the symptoms of MERS?

A person with MERS may have no symptoms, mild cold-like symptoms or a severe life-threatening illness. Typically, people with MERS develop respiratory symptoms that include:

• Cough.
• Fever.
• Shortness of breath.

Some people have also reported diarrhea, nausea and vomiting. MERS symptoms usually appear within two to 14 days after exposure to the virus.

What are possible complications of MERS?

In severe cases, MERS progresses to pneumonia and respiratory failure requiring mechanical ventilation. Kidney failure can also occur.

About 35% of people with MERS have died. However, the actual percentage may be lower because it does not include mild cases that go undiagnosed and unreported.

Those most likely to develop severe disease have underlying health conditions that weaken the immune system, such as:

• Cancer.
• Chronic heart disease.
• Chronic kidney disease.
• Chronic lung disease.
• Diabetes.

How is MERS diagnosed?

If you have respiratory symptoms, your healthcare provider will ask you about your medical history. Let your provider know if you traveled recently or had contact with sick people or camels.

Laboratory tests can determine if you have active MERS or a previous MERS infection. Your provider may collect several samples for laboratory testing, including:

• Lower respiratory tract sample: Your healthcare provider may collect fluid from your lungs by having you cough up sputum (phlegm) into a container. Alternatively, your provider may insert a thin, flexible tube down your throat and into your lungs to collect a sputum sample.
• Upper respiratory tract sample: This involves a swab of the inside of your nose or upper throat.
• Serum sample: Serum is the liquid part of your blood. Your provider will collect a blood sample, then spin it very fast in a centrifuge. Spinning separates the serum from the red and white blood cells and platelets.

Not all laboratories are approved to do MERS-CoV testing. Your provider may send the samples to your state health department laboratory or to the Centers for Disease Control and Prevention.

How is MERS treated?

Currently, there is no approved treatment for MERS. Your medical care will focus on managing your symptoms while your body fights the infection.

If you have mild symptoms, you can remain at home and take medications to relieve pain and fever. More severe cases may require hospital care, including:

• IV (intravenous) fluids.
• Supplemental oxygen.
• Mechanical ventilation.

How can I prevent spreading MERS to others?

If you know or think you may have MERS, take steps to prevent infecting others:

• Stay home.
• While at home, stay in a separate room and use a separate bathroom from others in your household.
• Wash your hands frequently.
• Wear a face mask when you are in the same room as someone else.
• Cover your mouth and nose with a tissue when you cough or sneeze, then throw the tissue away and wash your hands.
• Call your healthcare provider before you visit.
• If your symptoms are getting worse, call your provider right away.

When can I resume normal activities?

If you're feeling better, talk to your healthcare provider about when you can resume your normal activities. Your state or local health department can also give you guidance on how long you need to stay home to prevent spreading MERS to others.

How can I protect myself from MERS?

There is no vaccine for MERS. Steps for preventing MERS are similar to those for preventing all respiratory illnesses:

• Wash your hands frequently.
• Cover your nose and mouth with a tissue when you cough or sneeze.
• Avoid touching your eyes, nose and mouth.
• Avoid close contact with people who are sick.
• Clean and disinfect surfaces frequently.

To prevent getting MERS from camels:

• Wash your hands after touching camels and avoid contact with sick camels.
• Do not consume unpasteurized camel milk or uncooked camel meat.
• Avoid contact with camels if you have a chronic health condition or compromised immune system.

How do I protect myself when caring for a person with MERS?

If you are living with or caring for a person with MERS, health officials recommend additional precautions:

• Wear a face mask, gown and gloves if you have contact with the person’s body fluids or secretions.
• Wear gloves when handling and washing dishes, towels, bedding and laundry. Wash your hands after removing your gloves.

What is the prognosis for people with MERS?

You are unlikely to contract MERS unless you travel to the Arabian peninsula or come into close contact with someone who has recently traveled there and has symptoms.

If you do get MERS, you have a high risk of developing severe disease, especially if you have existing health conditions. Your healthcare provider will monitor you closely and provide supportive care to manage your symptoms.

When should I call my healthcare provider?

You should call your provider if you have symptoms of MERS and think you were exposed to MERS-CoV. Exposure may include direct contact with someone with MERS or if you or a close contact recently traveled to the Arabian Peninsula.

MERS symptoms can become quite severe and life-threatening. Contact your provider immediately if your symptoms are getting worse.

A note from Cleveland Clinic

MERS is a rare disease but not easily transmitted from person to person. If you plan to travel to the Arabian Peninsula, practice basic hygiene to prevent MERS. Wash your hands often, do not touch your face and be careful around camels. If you suspect MERS, call your healthcare provider immediately. They can offer testing and guidance for managing your condition and preventing the spread of MERS to those around you.