About MERS

Middle East Respiratory Syndrome (MERS) is an illness

caused by a virus (more specifically, a coronavirus)
called Middle East Respiratory Syndrome Coronavirus
(MERS-CoV). Most MERS patients developed severe
respiratory illness with symptoms of fever, cough and
shortness of breath. About 3 or 4 out of every 10
patients reported with MERS have died.
All cases are linked to the Arabian Peninsula

Health officials first reported the disease in Saudi

Arabia in September 2012. Through retrospective
(backward-looking) investigations, they later identified
that the first known cases of MERS occurred in Jordan
in April 2012. So far, all cases of MERS have been linked
through travel to, or residence in, countries in and near
the Arabian Peninsula. The largest known outbreak of
MERS outside the Arabian Peninsula occurred in the
Republic of Korea in 2015. The outbreak was associated
with a traveler returning from the Arabian Peninsula.
People with MERS can spread it to others

MERS-CoV has spread from ill people to others

through close contact, such as caring for or living with
an infected person.

MERS can affect anyone. MERS patients have ranged in

age from younger than 1 to 99 years old.
CDC continues to closely monitor the MERS situation
globally. We are working with partners to better
understand the risks of this virus, including the source,
how it spreads, and how to prevent infections. CDC
recognizes the potential for MERS-CoV to spread
further and cause more cases globally and in the U.S.
We have provided information for travelers and are
working with health departments, hospitals, and other
partners to prepare for this.

Symptoms & Complications

Most people confirmed to have MERS-CoV infection
have had severe respiratory illness with symptoms of:

 fever
 cough
 shortness of breath

Some people also had diarrhea and nausea/vomiting.

For many people with MERS, more severe
complications followed, such as pneumonia and kidney
failure. About 3 or 4 out of every 10 people reported
with MERS have died. Most of the people who died had
a pre-existing medical condition that weakened their
immune system, or an underlying medical condition
that hadn’t yet been discovered. Medical conditions
sometimes weaken people’s immune systems and
make them more likely to get sick or have severe
illness.
Pre-existing conditions among people who got MERS
have included

 diabetes
 cancer
 chronic lung disease
 chronic heart disease
 chronic kidney disease

Some infected people had mild symptoms (such as

cold-like symptoms) or no symptoms at all.

The symptoms of MERS start to appear about 5 or 6

days after a person is exposed, but can range from 2 to
14 days.

Transmission
MERS-CoV, like other coronaviruses, likely spreads from
an infected person’s respiratory secretions, such as
through coughing. However, we don’t fully understand
the precise ways that it spreads.

MERS-CoV has spread from ill people to others

through close contact, such as caring for or living with
an infected person. Infected people have spread MERS-
CoV to others in healthcare settings, such as hospitals.
Researchers studying MERS have not seen any ongoing
spreading of MERS-CoV in the community.
All reported cases have been linked to countries in and
near the Arabian Peninsula. Most infected people either
lived in the Arabian Peninsula or recently traveled from
the Arabian Peninsula before they became ill. A few
people have gotten MERS after having close contact
with an infected person who had recently traveled from
the Arabian Peninsula. The largest known outbreak of
MERS outside the Arabian Peninsula occurred in the
Republic of Korea in 2015 and was associated with a
traveler returning from the Arabian Peninsula.

Public health agencies continue to investigate clusters

of cases in several countries to better understand how
MERS-CoV spreads from person to person.

Prevention & Treatment

Prevention

There is currently no vaccine to protect people against

MERS. But scientists are working to develop one.

You can help reduce your risk of getting respiratory

illnesses:

 Wash your hands often with soap and water for at

least 20 seconds, and 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 personal contact, such as kissing, or sharing
cups or eating utensils, with sick people.
 Clean and disinfect frequently touched surfaces
and objects, such as doorknobs.

If you are caring for or living with a person confirmed

to have, or being evaluated for, MERS-CoV infection,
see Interim Guidance for Preventing MERS-CoV from
Spreading in Homes and Communities.
Treatment

There is no specific antiviral treatment recommended

for MERS-CoV infection. Individuals with MERS often
receive medical care to help relieve symptoms. For
severe cases, current treatment includes care to
support vital organ functions.

People Who May Be at Increased Risk for

MERS
On This Page

 Recent Travelers from the Arabian Peninsula

  Close Contacts of an Ill Traveler from the Arabian
Peninsula
 Close Contacts of a Confirmed Case of MERS
 Healthcare Personnel Not Using Recommended
Infection-Control Precautions
 People with Exposure to Camels
Recent Travelers from the Arabian Peninsula

If you develop a fever* 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**, you should call ahead to a
healthcare provider and mention your recent travel.
Close Contacts of an Ill Traveler from the Arabian Peninsula

If you have had close contact*** with someone within

14 days after they traveled from a country in or near
the Arabian Peninsula**, and the traveler has/had
fever* 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* 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.
Close Contacts of a Confirmed Case of MERS
If you have had close contact*** with someone who has
a confirmed MERS-CoV infection, you should contact a
healthcare provider for an evaluation. Your healthcare
provider may request laboratory testing and outline
additional recommendations, depending on the
findings of your evaluation and whether you have
symptoms. You most likely will be asked to monitor
your health for 14 days, starting from the day you were
last exposed to the ill person. Watch for these
symptoms:

 Fever*. Take your temperature twice a day.

 Coughing
 Shortness of breath
 Other early symptoms to watch for are chills, body
aches, sore throat, headache, diarrhea,
nausea/vomiting, and runny nose.

If you develop symptoms, call ahead to your healthcare

provider as soon as possible and tell them about your
possible exposure to MERS-CoV so the office can take
steps to keep other people from getting infected. Ask
your healthcare provider to call the local or state health
department.

Top of Page
Healthcare Personnel Not Using Recommended Infection-
Control Precautions
Healthcare personnel should adhere to recommended
infection control measures, including standard, contact,
and airborne precautions, while managing
symptomatic close contacts, patients under
investigation, and patients who have probable or
confirmed MERS-CoV infections. They should also use
recommended infection control precautions when
collecting specimens.

Healthcare personnel who had close contact*** with a

confirmed case of MERS while the case was ill, if not
using recommended infection control precautions (e.g.,
appropriate use of personal protective equipment), are
at increased risk of developing MERS-CoV infection.
These individuals should be evaluated and monitored
by a healthcare professional with a higher index of
suspicion. For more information, see Interim Infection
Prevention and Control Recommendations for
Hospitalized Patients with Middle East Respiratory
Syndrome Coronavirus (MERS-CoV).
People with Exposure to Camels

Direct contact with camels is a risk factor for human

infection with MERS-CoV.

The World Health Organization has posted a general

precaution for anyone visiting farms, markets, barns, or
other places where animals are present. Travelers
should practice general hygiene measures, including
regular handwashing before and after touching
animals, and avoiding contact with sick animals.
Travelers should also avoid consumption of raw or
undercooked animal products. For more information,
see WHO’s Frequently Asked Questions on MERS-CoV.
(Should people avoid contact with camels or camel
products? Is it safe to visit farms, markets, or camel
fairs?)external icon

The World Health Organization considers certain

groups to be at high risk for severe MERS. These
groups include people with diabetes, kidney failure, or
chronic lung disease, and people who have weakened
immune systems. The World Health Organization
recommends that these groups take additional
precautions:

 Avoid contact with camels

 Do not drink raw camel milk or raw camel urine
 Do not eat undercooked meat, particularly camel
meat

*Fever may not be present in some patients, such as

those who are very young, elderly, immunosuppressed,
or taking certain medications. Clinical judgement
should be used to guide testing of patients in such
situations.

**Countries considered in and near the Arabian

Peninsula include: Bahrain; Iraq; Iran; Israel, the West
Bank, and Gaza; Jordan; Kuwait; Lebanon; Oman; Qatar;
Saudi Arabia; Syria; the United Arab Emirates (UAE);
and Yemen.

***Close contact is defined as a) being within

approximately 6 feet (2 meters), or within the room or
care area, of a confirmed MERS case for a prolonged
period of time (such as caring for, living with, visiting,
or sharing a healthcare waiting area or room with, a
confirmed MERS case) while not wearing
recommended personal protective equipment or PPE
(e.g., gowns, gloves, NIOSH-certified disposable N95
respirator, eye protection); or b) having direct contact
with infectious secretions of a confirmed MERS case
(e.g., being coughed on) while not wearing
recommended personal protective equipment. See
CDC’s Interim Infection Prevention and Control
Recommendations for Hospitalized Patients with MERS.
Data to inform the definition of close contact are
limited; considerations when assessing close contact
include the duration of exposure (e.g., longer exposure
time likely increases exposure risk) and the clinical
symptoms of the person with MERS (e.g., coughing
likely increases exposure risk). Special consideration
should be given to those exposed in healthcare
settings. For detailed information regarding healthcare
personnel (HCP) please review CDC’s Interim U.S.
Guidance for Monitoring and Movement of Persons
with Potential Middle East Respiratory Syndrome
(MERS-CoV) Exposure. Transient interactions, such as
walking by a person with MERS, are not thought to
constitute an exposure; however, final determination
should be made in consultation with public health
authorities.