MERS-CoV: Evaluating Patients and Managing Close Contacts

CDC Interim Guidance for Health Professionals

Susan Gerber, MD


June 23, 2014

Editorial Collaboration

Medscape &

MERS: Clinical Presentation

The first 2 US cases of Middle East Respiratory Syndrome (MERS), caused by a coronavirus called MERS-CoV, were confirmed in travelers to the United States from Saudi Arabia in May 2014. In this interconnected world, we anticipate additional importations. That's why it's important that public health agencies, healthcare facilities, and providers be prepared to detect patients who should be evaluated for MERS, and manage their close contacts.

Limited data on the clinical presentation of MERS are available; most published clinical information to date is from critically ill patients. At hospital admission, common signs and symptoms include fever, chills/rigors, headache, nonproductive cough, dyspnea, and myalgia. Other symptoms can include sore throat, coryza, sputum production, dizziness, nausea and vomiting, diarrhea, and abdominal pain. Atypical presentations including mild respiratory illness without fever and diarrheal illness preceding development of pneumonia have been reported. Clinical judgment should be exercised when evaluating patients, as information continues to evolve on clinical presentation and modes of transmission.

The Centers for Disease Control and Prevention (CDC) recently updated its Interim Guidance for Health Professionals and definitions for patients under investigation and close contact. According to this guidance, healthcare providers should evaluate patients in the United States for MERS-CoV infection if they meet the following criteria, defined as a patient under investigation (PUI):

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

   - A history of travel from countries in or near the Arabian Peninsula (Bahrain; Iran; Iraq; Israel, the West Bank, and Gaza; Jordan; Kuwait; Lebanon; Oman; Qatar; Saudi Arabia; Syria; the United Arab Emirates [UAE]; and Yemen) 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 (eg, 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; eg, 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 in or near the Arabian Peninsula in which recent healthcare-associated cases of MERS have been identified. (As of June 1, 2014, this list includes Jordan, Saudi Arabia, and UAE; this may change as more information becomes available.)

Healthcare providers should immediately report PUIs to their state or local health department. Health departments should immediately report PUIs to CDC using the MERS PUI short form.

MERS: Evaluation and Management of Close Contacts

"Close contact" is defined as (a) being within approximately 6 feet (2 meters) or within the room or care area for a prolonged period of time (eg, healthcare personnel, household members) while not wearing recommended personal protective equipment (PPE) (ie, gowns, gloves, respirator, eye protection); or (b) having direct contact with infectious secretions (eg, being coughed on) while not wearing recommended PPE. Data to inform the definition of close contact are limited. At this time, brief interactions, such as walking by a person, are considered low risk and do not constitute close contact. (The complete definition for close contact can be found here.

Close Contacts of a Confirmed Case

As part of investigation of confirmed cases, in consultation with a state or local health department, a person who develops fever or symptoms of respiratory illness within 14 days following close contact with a confirmed case of MERS while the case was ill should be evaluated for MERS-CoV infection.

Other contacts of the ill person, such as community contacts or contacts on conveyances (eg, airplane, bus), may be considered for evaluation in consultation with state and local health departments.

Symptomatic contacts should be evaluated and, depending on their clinical history and presentation, considered for more extensive MERS-CoV testing, including real-time reverse-transcriptase polymerase chain reaction (rRT-PCR) testing of lower respiratory and serum specimens, and possibly MERS-CoV serology if symptom onset was more than 14 days prior.

Ill Contacts Who Don't Require Hospitalization

Close contacts who are ill and do not require hospitalization for medical reasons while being evaluated for MERS-CoV infection may be cared for and isolated in their home. ("Isolation" is defined as the separation or restriction of activities of an ill person with a contagious disease from those who are well). For asymptomatic close contacts being evaluated for MERS-CoV, the possible benefit of home quarantine or other measures, such as wearing masks, is uncertain owing to lack of information about transmissibility from persons with asymptomatic infection.

Asymptomatic contacts who test positive by PCR, especially on respiratory specimens or serum, likely pose a risk for transmission, although the magnitude and contributing factors are unknown. Providers should contact their state or local health department to discuss home isolation, home quarantine, or other measures for close contacts, especially for patients who test positive, and to discuss criteria for discontinuing any such measures.

Recommendations may be modified as more data become available. For more information, see CDC's Interim Home Care and Isolation Guidance for MERS-CoV.

Close Contacts of a PUI

Evaluation and management of close contacts of a PUI should be discussed with state and local health departments. Close contacts of a PUI should monitor themselves for fever and respiratory illness and seek medical attention if they become ill within 14 days after contact; healthcare providers should consider the possibility of MERS in these contacts. Close contacts who do not require hospitalization for medical reasons may be cared for in their home. For more information, see CDC's Interim Home Care and Isolation Guidance for MERS-CoV.

MERS-CoV Testing Guidance

Clusters of Illness Where Testing Should Be Considered

Clusters of patients with severe acute respiratory illness (eg, fever and pneumonia requiring hospitalization) without a recognized link to a case of MERS-CoV infection or to travelers from countries in or near the Arabian Peninsula should be evaluated for common respiratory pathogens. Examples of respiratory pathogens causing community-acquired pneumonia include influenza A and B, respiratory syncytial virus, Streptococcus pneumoniae, and Legionella pneumophila.

In accordance with the World Health Organization's (WHO) guidance for MERS-CoV, a cluster is defined as 2 or more persons with onset of symptoms within the same 14-day period, and who are associated with a specific setting, such as a classroom, workplace, household, extended family, hospital, other residential institution, military barracks, or recreational camp. See WHO's Interim Surveillance Recommendations for Human Infection with Middle East Respiratory Syndrome Coronavirus.

If the illnesses remain unexplained, providers should consider testing for MERS-CoV, in consultation with state and local health departments.

Laboratory Testing in MERS

To increase the likelihood of detecting MERS-CoV infection in suspected cases, CDC recommends collecting multiple specimens from different sites at different times after symptom onset. For more information, see CDC's Interim Guidelines for Collecting, Handling, and Testing Clinical Specimens from PUIs for MERS-CoV. In a PUI, CDC strongly recommends testing a lower respiratory specimen (eg, sputum, broncheoalveolar lavage fluid, or tracheal aspirate), a nasopharyngeal/oropharyngeal swab, and serum, via the CDC MERS-CoV rRT-PCR assay. If symptom onset was more than 14 days prior, CDC also strongly recommends additional testing of a serum specimen via the CDC MERS-CoV serologic assay. Healthcare providers should contact their state or local health department to request MERS-CoV laboratory testing.

Infection Control and MERS

Healthcare providers 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. Recommended infection-control precautions should also be utilized when collecting specimens:

For CDC guidance on MERS-CoV infection control in healthcare settings, see Interim Infection Prevention and Control Recommendations for Hospitalized Patients with MERS-CoV.

For CDC interim guidance to prevent MERS-CoV from spreading in homes and communities in the United States, see Interim Home Care and Isolation Guidance for MERS-CoV.

CDC continues to work closely with the WHO and international partners to better understand the source of MERS-CoV, how it spreads, and the risks to public health. Healthcare providers should contact their state or local health departments if they have questions.

Web Resources

CDC Middle East Respiratory Syndrome (MERS)

CDC MERS: Information for Healthcare Providers: Interim guidance, case definitions, infection prevention and control recommendations, home care guidance, preparedness checklists, and clinical features of MERS.

CDC MERS: Information for Health Departments: Interim guidance, data collection tools, case definitions, home care, and isolation guidance.

CDC MERS: Information for Laboratories: Guidelines for clinical specimens, laboratory biosafety guidelines.

CDC Features: MERS Imported to US

CDC. First Confirmed Middle East Respiratory Syndrome Coronavirus (MERS-CoV) Cases in the United States, updated Information on the Epidemiology of MERS-CoV Infection, and Guidance for the Public, Clinicians, and Public Health Authorities -- May 2014. MMWR Morb Mortal Wkly Rep. 2014;63;431-436.

Dr. Susan Gerber is Team Lead for the Respiratory Viruses and Picornavirus Team, Division of Viral Diseases, at the Centers for Disease Control and Prevention (CDC). She received her MD from Loyola University and completed a pediatric residency and pediatric infectious disease fellowship at the University of Chicago. Dr. Gerber later joined the University of Chicago faculty in the section of pediatric infectious disease. Dr. Gerber acquired 14.5 years of experience in local public health with work on communicable diseases at the Cook County Department of Public Health and the Chicago Department of Public Health.