Frequently Asked Questions and Answers

A: Middle East Respiratory Syndrome (MERS) is a viral respiratory illness. Learn about MERS.

A: MERS-CoV is the acronym for Middle East Respiratory Syndrome Coronavirus, the virus that causes MERS. When referring to the virus and not the illness, CDC uses MERS-CoV. When referring to the illness, CDC uses MERS. The virus was first reported in 2012 in Saudi Arabia. It is different from any other coronaviruses that researchers have found in people before.

A: We don’t know for certain where the virus came from. However, it likely came from an animal source. In addition to humans, MERS-CoV has been found in camels in several countries. It appears that some people became infected after contact with camels, although more information is needed to figure out the possible role that camels and other animals may play in the transmission of MERS-CoV.

A: Read about MERS symptoms and complications.

A: Learn about how MERS-CoV spreads.

A: Yes, two patients in the U.S. tested positive for MERS-CoV infection, both in May 2014. Get the most up-to-date information about MERS in the U.S.

A: CDC works 24/7 to protect people’s health. It is CDC’s job to be concerned and move quickly whenever there is a potential public health problem. CDC continues to closely monitor the MERS situation globally. CDC is working with the World Health Organization and other partners to better understand the virus, how it spreads, the source, and risks to the public’s health. We recognize the potential for MERS-CoV to spread further and cause more cases in the United States and globally. In preparation for this, we have:

• Continued to collaborate with international partners on epidemiologic and laboratory studies to better understand MERS
• Improved the way we collect data about MERS cases
• Increased lab testing capacity in states to detect cases
• Developed guidance and tools for health departments to conduct public health investigations when MERS cases are suspected or confirmed
• Provided recommendations for healthcare infection control and other measures to prevent disease spread
• Provided guidance for flight crews, Emergency Medical Service (EMS) units at airports, and U.S. Customs and Border Protection (CPB) officers about reporting ill travelers to CDC
• Disseminated up-to-date information to the general public, international travelers, and public health partners
• Used Advanced Molecular Detection (AMD) methods to sequence the complete virus genome on specimens from cases to help evaluate and further describe the characteristics of MERS-CoV. (See U.S. MERS story: Decoding MERS Coronavirus: AMD Provides Quick Answers.)

A: The MERS situation in the U.S. represents a very low risk to the general public in this country. Only two patients in the U.S. have tested positive for MERS-CoV infection—both in May 2014 after recently traveling from Saudi Arabia—while more than 900 have tested negative. CDC continues to closely monitor the situation. Read to find out if you are at increased risk for MERS-CoV infection.

A: Visit the MERS prevention and treatment page to learn about how to protect yourself from respiratory illnesses, like MERS.

Also see Interim Guidance for Preventing MERS-CoV from Spreading in Homes and Communities. This guidance is intended for caregivers, household members, and other close contacts of people confirmed to have, or being evaluated for, MERS-CoV infection.

A: If you have had close contact(1) with a confirmed MERS case within the last 14 days without using the recommended infection control precautions, you should contact a healthcare provider for an evaluation. See People Who May Be at Increased Risk for MERS.

It’s important to note, however, that most people who had close contact with someone who had MERS did not get infected or become ill. We are still learning about MERS-CoV and how it spreads.

A: Yes, read CDC’s travel notices on MERS in the Arabian Peninsula.(2)

A: If you develop a fever(3) and symptoms of respiratory illness, such as cough or shortness of breath, within 14 days after traveling from countries in or near the Arabian Peninsula(2), you should call ahead to a healthcare provider and mention your recent travel. See People Who May Be at Increased Risk for MERS.

A: If you have had close contact(1) with someone within 14 days after they traveled from a country in or near the Arabian Peninsula(2), and the traveler has/had fever(3) and symptoms of respiratory illness, such as cough or shortness of breath, you should monitor your health for 14 days, starting from the day you were last exposed to the ill person. If you develop fever(3) and symptoms of respiratory illness, such as cough or shortness of breath, you should call ahead to a healthcare provider and mention your recent contact with the traveler. See People Who May Be at Increased Risk for MERS.

A: CDC may detain individuals arriving in the U.S. or traveling between states who they believe are infected with a quarantinable disease, including MERS, as of July 31, 2014, per amended U.S. Executive Order 13295. “Isolation” is used to separate ill people who have a contagious disease from those who are healthy; “quarantine” is used to separate and restrict the movement of well people who may have been exposed to a contagious disease to see if they become ill. See About Quarantine and Isolation.

A: Currently, there is no vaccine available to protect against MERS.

A: Learn about MERS treatment.

A: If you develop a fever(3) and symptoms of respiratory illness, such as cough or shortness of breath, within 14 days after travel from a country in or near the Arabian Peninsula(2), you should call ahead to a healthcare provider and mention your recent travel or close contact. If you have had close contact(1) with someone showing these symptoms who has recently traveled from this area, you should call ahead to a healthcare provider and mention your recent travel or close contact. Your healthcare provider will work with your state’s public health department to test you for MERS.

A: There are two main ways to determine if a person is, or has been, infected with MERS-CoV.

• One type of test, conducted by state and CDC labs, is called PCR, or polymerase chain reaction, assays.
  • PCR assays are done with respiratory, serum, or stool samples and can quickly indicate if a person has an active infection with MERS-CoV.
• A second type of test, conducted by CDC lab, is called serology testing.
  • Serology testing uses serum samples and is designed to look for antibodies to MERS-CoV that would indicate a person had been previously infected with the virus and developed an immune response or has an active MERS-CoV infection for approximately 14 or more days.
  • Serology for MERS-CoV often includes three separate tests – (1) a screening test called ELISA or enzyme-linked immunosorbent assay, (2) a confirmatory test called IFA or Immunofluorescent assay, and (3) a slower, but more definitive confirmatory test called the neutralizing antibody assay.

For more information see CDC Laboratory Testing for MERS-CoV.

A: For recommendations and guidance on the case definitions; infection control, including personal protective equipment guidance; home care and isolation; case investigation; and specimen collection and shipment, see Information for Healthcare Professionals.

A: No. MERS-CoV is not the same coronavirus that caused severe acute respiratory syndrome (SARS) in 2003. However, like the SARS virus, MERS-CoV is most similar to coronaviruses found in bats. CDC is still learning about MERS.