Managing MERS Cases and Contacts

What to know

  • Any MERS case detected in the United States, and any person under investigation with equivocal or presumptive positive MERS test results, must be immediately reported to CDC with residual specimen sent for confirmatory testing.
  • State or local health departments should coordinate isolation for people with confirmed MERS and home quarantine for their contacts.

Confirmed case: Definition, reporting, and next steps

A confirmed case is a person who has laboratory confirmation of MERS-CoV infection. Confirmatory laboratory testing requires a positive MERS real-time reverse transcription polymerase chain reaction (rRT-PCR) test.

In accordance with the Emergency Use Authorization (EUA) instructions for use of the US MERS rRT-PCR, any specimen with a MERS-CoV presumptive positive interpretation identified at a public health laboratory should be shipped to CDC for confirmatory testing. A single positive MERS rRT-PCR test with confirmatory genomic sequencing is also acceptable. Specimens shipped to CDC should be submitted in accordance with the CDC-10488 test order.

CDC requests that state or local health departments complete the MERS PUI short form for any confirmed positive MERS case. State or local health departments should also immediately schedule a follow-up call/meeting with CDC to discuss further epidemiologic investigation(s) and management of the confirmed case.

State or local health departments should coordinate isolation for people with confirmed MERS and home quarantine for their contacts, respectively.

Reporting MERS Persons Under Investigation (PUIs)

  • State and local health departments must submit all CDC MERS rRT-PCR results (e.g., negative, positive, equivocal) via the Laboratory Response Network (LRN).
    • Any MERS case detected in the United States, and any PUI with equivocal or presumptive positive MERS test results, must be immediately reported to CDC with residual specimen sent for confirmatory testing.
  • CDC no longer requests that state and local health departments submit short forms for PUIs who test negative for MERS.
    • However, MERS PUI short forms are available to use as optional tools when investigating PUIs.
    • NOTE: CDC may revise optional submission of the MERS short form for PUIs in the future if public health needs change.
  • CDC staff are available for epidemiologic and laboratory consultation for MERS.
    • State health department personnel may contact the CDC Emergency Operations Center by email (eocreport@cdc.gov) or phone (770-488-7100) with any questions about MERS PUIs, MERS testing inquiries, or to report any positive MERS testing completed at state or local public health laboratories.
      • Several state or local public health labs offer MERS testing. Clinicians should first contact their local and/or state health departments to discuss MERS PUIs and testing.

Evaluation and management of close contacts

Close contacts of a confirmed case

As part of investigation of confirmed cases, close contactsA of a confirmed case should be actively monitored by health departments, or monitor themselves, for fever Bor symptoms of respiratory illness for 14 days after the close contact. State and local public health departments should strongly consider quarantining contacts during active monitoring periods. A person who develops fever Bor symptoms of respiratory illness within 14 days following close contactA with a confirmed case of MERS should be tested for MERS infection.

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

Clinicians and public health professionals should be aware that a wide spectrum of illness in patients with MERS has been reported, ranging from asymptomatic to severe acute respiratory illness resulting in death. Symptomatic contacts should be tested. This includes testing of upper and (if possible) lower respiratory specimens for MERS by rRT-PCR. If symptom onset was more than 14 days prior, the patient's case should be discussed further with state and local health departments and CDC.

People who are confirmed to have MERS and who do not require hospitalization for medical reasons may be isolated at home; this decision should be made by the state or local health department based on individual circumstances and done in conjunction with CDC. Close contacts who are symptomatic and awaiting MERS testing or MERS testing results, and who do not require hospitalization for medical reasons, should be quarantined. Quarantine at home may be considered; this decision should be made by the state or local health department and in conjunction with CDC. Providers should contact their state or local health department to discuss home isolation or home quarantine for people with confirmed MERS or their contacts, respectively.

All contacts should be monitored for 14 days after last exposure. Contacts with no apparent symptoms who test positive for MERS by rRT-PCR in respiratory specimens likely pose a risk of transmission, although the magnitude and contributing factors are unclear.

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.

Clusters of respiratory illness in which MERS should be considered

Clusters of patients with severe acute respiratory illness without recognized links to a case of MERS-CoV infection or to travelers from countries in or near the Arabian PeninsulaA should be tested for common respiratory pathogens. If the illnesses remain unexplained, providers should consider testing for MERS, in consultation with state and local health departments and CDC.

  1. 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 (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 PPE. See Prevention and Control for Hospitalized MERS Patients. 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, please review CDC 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.
  2. 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.