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Middle East Respiratory Syndrome (MERS) - Symptoms, Causes, Diagnosis, and Treatment

Published on May 14, 2020 and last reviewed on Apr 11, 2023   -  4 min read


Middle East respiratory syndrome (MERS) is a respiratory illness caused by the virus MERS-CoV. Learn about its symptoms, causes, diagnosis, and treatment.

Middle East Respiratory Syndrome (MERS) - Symptoms, Causes, Diagnosis, and Treatment


Middle East respiratory syndrome, also called MERS, is a respiratory disease that was first found in Saudi Arabia in 2012. It is caused by the middle east respiratory syndrome coronavirus (MERS‐CoV). This virus belongs to the large family of viruses called coronaviruses, which are responsible for severe acute respiratory syndrome (SARS) and the COVID-19 pandemic.

Like the other strains of coronavirus, MERS-CoV also causes fever, cough, and shortness of breath. The other not-so-common symptoms are pneumonia, diarrhea, nausea, vomiting, and abdominal cramps. Some patients who tested positive for this infection did not show any symptoms or were asymptomatic.

Dromedary (Arabian camels) are thought to be the major reservoir host for MERS-CoV. The virus is believed to be spread to humans from infected camels and human-to-human transmission. The spread occurs through close contact, especially while giving unprotected care to patients. Healthcare-associated outbreaks are responsible for the outbreaks in Saudi Arabia, the UAE, and the Republic of Korea. MERS-CoV continues to cause localized outbreaks. This infection can be fatal if it progresses to respiratory or kidney failure. Data also shows 1 in 3 people (35 percent) die from MERS. The risk of severe illness is high in older adults and immunocompromised individuals. Treatment focuses on relieving symptoms with the help of rest, painkillers, fluids, and oxygen therapy.

What Causes MERS?

As MERS-CoV is transmitted between animals and humans, it is called a zoonotic virus. This virus is said to have originated in bats, which then infect dromedary camels. Researchers have identified MERS-CoV in camels in many countries.

The modes of transmission are:

  1. Animals to Humans - As mentioned before, dromedary camels are the animal source of infection in humans. Scientists have isolated strains of MERS-CoV from Arabian camels in Egypt, Qatar, Saudi Arabia, and many other countries.

  2. Human to Human - Providing unprotected care to an infected patient is the main source of human-to-human transmission. Many clusters of such cases have been reported in healthcare facilities.

How Does the Virus Spread?

MERS spreads from one person to another through infected respiratory droplets. These droplets are generated when an infected person coughs or sneezes without covering his or her mouth. One can get infected if one breathes in these infected droplets, or if the droplet comes in contact with one’s mouth, nose, or eyes. Humans can get infected by camels through respiratory droplets, and their meat, milk, and urine.

What Are the Signs and Symptoms of MERS?

The incubation period that is the time between exposure to the virus and symptoms is two to 14 days (usually five days). The symptoms of MERS range from asymptomatic to mild symptoms to severe respiratory disease. The typical symptoms include:

  1. Fever.

  2. Cough.

  3. Shortness of breath.

  4. Diarrhea.

  5. Sore throat.

  6. Runny nose.

  7. Muscle aches.

Severe symptoms like kidney failure, pneumonia, and respiratory failure have also been reported.

Who Is at Risk of Developing Severe Illness Due to MERS-CoV?

People who are at risk of getting severe illness include:

  • Older adults.

  • Immunocompromised people (people who are taking immunosuppressant medications or those under chemotherapy).

  • People with pre-existing chronic diseases like asthma, cancer, diabetes, and liver disease.

How Is MERS Diagnosed?

This virus is detected using the polymerase chain reaction (PCR) test. This test is done on a sample of respiratory secretions or blood. If the doctor suspects that a person might be infected with MERS-CoV, based on the travel history and symptoms, he or she might be asked to get this test done. ELISA (enzyme-linked immunosorbent assay) and IFA (immunofluorescence assay) detect the antibodies to MERS-CoV. Apart from this, the doctor might suggest taking the following:

  1. Chest X-ray - To check for pneumonia.

  2. CT (computed tomography) Scan - To get detailed images of the lungs.

  3. Blood Test - To check how well kidneys are functioning.

How Is MERS Treated?

As of now, no cure or vaccine is available for MERS. Vaccines and treatments are under development. Doctors provide medicines and therapies focusing on specific symptoms, such as:

  1. Paracetamol or Acetaminophen - To relieve fever.

  2. Analgesics - To reduce pain.

  3. Oxygen Therapy - To ease breathing.

  4. Antibiotics - To treat superimposed bacterial infection.

  5. IV (intravenous) Fluids and Electrolytes - To prevent dehydration.

How Can MERS Be Prevented?

One can reduce the risk of MERS by following these preventive tips:

  1. Hands should be washed regularly with soap and water (for 20 seconds), or an alcohol-based hand sanitizer should be used. Make sure to wash hands when they are visibly soiled, after using the toilet, before and after eating, or cooking.

  2. Avoid eating undercooked meats.

  3. Make sure to cover the mouth and nose with a tissue or forearm while sneezing or coughing.

  4. Wash fruits and vegetables properly before eating.

  5. If a person has a cough, cold, or other respiratory symptoms, he or she should avoid going out and remain at home.

  6. Do not come in contact with people who are exhibiting respiratory symptoms.

  7. When visiting crowded areas, use a mask.

  8. Do not consume raw camel meat or milk. It is safe to consume properly cooked camel meat and pasteurized camel milk.

What Is the Difference Between COVID-19 and MERS?

  • Both COVID-19 and MERS are distinct respiratory illnesses. They are produced by various viruses in the coronavirus family. The SARS-CoV-2 viral infection causes COVID-19.

  • Researchers think that SARS-CoV-2 started in bats, similar to how MERS-CoV did. Researchers are currently attempting to determine how it spreads to people.

  • The SARS-CoV-2 virus first appeared in Wuhan, China, in December 2019, and on March 11, 2020, the WHO declared a worldwide pandemic.

  • According to research, COVID-19 and MERS share a clinical presentation, but COVID-19 has a much-reduced mortality rate (2.3 % compared to 35 % for MERS).

  • However, compared to MERS and SARS, COVID-19 reliably produces less severe symptoms, making it easier for the virus to spread within a population.

  • The incidence of COVID-19 complications is comparable to that of SARS complications and is lower than that of MERS complications.


MERS is a serious respiratory disease brought on by the coronavirus MERS-CoV. It results in a fever, a cough, and breathlessness. As a precaution against MERS, the WHO does not presently advise any travel or trade restrictions. Localized MERS breakouts are rare but they do still occur. Official organizations are trying to create a vaccine and continue to track the prevalence of MERS.

Frequently Asked Questions


Which Organs Does MERS Affect?

MERS is a viral infection of the lungs that causes breathing problems. It could also harm the kidneys and other organs. MERS is caused by a virus known as coronavirus. As a result, this virus is also referred to as MERS-coronavirus.


Who Is Susceptible to MERS?

MERS is spread from person to person via infected respiratory droplets. These droplets form when an infected person coughs or sneezes without covering their mouth. One can become infected if one breathes in infected droplets or comes into contact with them through the mouth, nose, or eyes. Humans can get infected by camel respiratory droplets, meat, milk, and urine.


Can MERS Affect the Brain?

MERS-CoV infection of the CNS causes complement activation, which causes inflammation-mediated brain tissue damage. Other complications include severe symptoms like kidney failure, pneumonia, and respiratory failure.


Is There a Vaccine Available for MERS?

There is currently no specific treatment or vaccine for MERS, but several vaccines are developing. Treatment is supportive and tailored to the individual's clinical condition, which includes:
- Paracetamol or Acetaminophen.
- Analgesics.
- Oxygen therapy
- Antibiotics
- IV (intravenous) fluids and electrolytes.


Is MERS Associated With COVID?

MERS and COVID-19 are caused by different coronavirus strains. The SARS-CoV-2 virus causes COVID-19. Like MERS-CoV, SARS-CoV-2 is thought to have originated in bats. Even though COVID-19 causes symptoms similar to MERS, the death rate is only 3 to 4 %.


Can MERS Be Asymptomatic?

The incubation period, or the time between virus exposure and symptoms, ranges from two to 14 days (usually five days). MERS symptoms range from asymptomatic to mild to severe respiratory disease. The following are typical symptoms:
- Fever.
- Cough.
- Breathing difficulty.
- Diarrhea.


Is MERS-Cov Still Present?

From April 2012 to October 2022, laboratories confirmed 2600 cases of Middle East respiratory syndrome (MERS) worldwide, with 935 deaths at a case-fatality ratio (CFR) of 36 %. Saudi Arabia reported most of these cases, with 2193 cases and 854 related deaths (CFR: 39 %).


What Is the Outlook of MERS?

Approximately 35% of MERS patients have died. The actual percentage could be lower because it excludes mild cases that go undiagnosed and unreported. Those with underlying medical conditions that weaken the immune system, such as cancer, are more likely to develop severe disease.


Is MERS a More Serious Disease Than SARS?

Both diseases are potentially fatal to humans. SARS is caused by a coronavirus called SARS-CoV, whereas MERS is caused by a coronavirus called Middle East respiratory syndrome coronavirus (MERS-CoV). SARS-CoV first appeared in China about two decades ago and quickly spread to other countries. On the other hand, SARS has a fatality rate of 9.5 %, which is significantly lower than MERS (34.4 %).

Article Resources

Last reviewed at:
11 Apr 2023  -  4 min read




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