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CDPH Middle East Respiratory Syndrome Coronavirus (MERS-CoV) Information Webpage 


In September 2012, the World Health Organization announced the discovery of a novel coronavirus. This virus has been named the Middle East Respiratory Syndrome Coronavirus (MERS-CoV). MERS-CoV has been identified in several countries in the Arabian Peninsula (http://www.who.int/csr/disease/coronavirus_infections/en/index.html). A small number of cases have also been reported in Europe, Asia, North Africa and in March 2014, the United States; all of the cases reported in countries outside of the Middle East had either traveled to the Middle East or had been in close contact with a sick person who had recently traveled to the Middle East. Common symptoms in patients with MERS-CoV include a respiratory illness with fever, cough, shortness of breath, and breathing difficulties. Most patients have had pneumonia. Some patients have also had kidney failure. Outbreaks in health care facilities have been frequent. Patients with underlying co-morbidities such as diabetes, heart or lung disease, or immunosuppression, appear to be at the highest risk of developing severe disease. Fortunately, it appears that the virus is not readily transmitted person-to-person. Limited transmission has occurred in household settings where there were close family contacts. It can also spread from infected patients to healthcare personnel.

No travel warnings or restrictions have been issued related to MERS-CoV. The U.S. Centers for Disease Control and Prevention (CDC) is recommending surveillance and testing for individuals who have unexplained severe respiratory illness and history of travel to countries in the Arabian Peninsula or neighboring countries*.

Patient Under Investigation (PUI)

A person with the following characteristics should be considered a patient under investigation (PUI):

A. Fever AND pneumonia or acute respiratory distress syndrome (based on clinical or radiological evidence) AND EITHER:

  • a history of travel from countries in or near the Arabian Peninsula* within 14 days before symptom onset, OR
  • close contact** with a symptomatic traveler who developed fever and acute respiratory illness (not necessarily pneumonia) within 14 days after traveling from countries in or near the Arabian Peninsula* OR
  • a member of a cluster of patients with severe acute respiratory illness (e.g., fever and pneumonia requiring hospitalization) of unknown etiology in which MERS-CoV is being evaluated, in consultation with state and local health departments).


B. Fever AND symptoms of respiratory illness (not necessarily pneumonia; e.g. cough, shortness of breath) AND being in a healthcare facility (as a patient, worker, or visitor) within 14 days before symptom onset in a country or territory in or near the Arabian Peninsula in which recent healthcare-associated cases of MERS have been identified.*

*Arabian Peninsula or neighboring countries include: Bahrain, Iran, Iraq, Israel, Jordan, Kuwait, Lebanon, Palestinian territories, Oman, Qatar, Saudi Arabia, Syria, the United Arab Emirates, and Yemen.

**Close contact is defined as: a) any person who provided care for the patient, including a healthcare worker or family member, or had similarly close physical contact; or b) any person who stayed at the same place (e.g. lived with, visited) as the patient while the patient was ill.


Infection Control Guidance for MERS-CoV Infection

CDC is recommending that infection control guidance developed for SARS be implemented for patients with known or suspected MERS-CoV infection. Therefore, Airborne and Contact Precautions, in addition to Standard Precautions, should be applied when caring for patients with known of possible MERS-CoV infection. CDC interim infection prevention and control guidance for hospitalized patients with MERS-CoV is available at: http://www.cdc.gov/coronavirus/mers/infection-prevention-control.html. CDC infection control guidance for SARS is available at: http://www.cdc.gov/sars/infection/.

General Information
Information for Health Professionals
General Guidelines for Preventing Transmission
Infection Control
Last modified on: 7/3/2014 10:45 AM