Managing MERS Cases and Contacts for Public Health Professionals

Managing MERS Cases and Contacts for Public Health Professionals
Updated Mar. 18, 2024

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 ( 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


As part of investigation of confirmed cases, close contacts1of a confirmed case should be actively monitored by health departments, or monitor themselves, for fever2or 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 fever2 or symptoms of respiratory illness within 14 days following close contact1 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.

For more information, see CDC’s Who and When to Test.


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-CoV Infection 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 Peninsula1 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.