MERS-CoV Case Definitions

Patients should be evaluated for MERS-CoV infection in consultation with the state and local health departments. You can find more information, at CDC’s here:

Patient Under Investigation (PUI)

A person who has both clinical features and an epidemiologic risk should be considered a patient under investigation (PUI) based on one of the following scenarios:

Severe illness:

• Fever and pneumonia or acute respiratory distress syndrome based on clinical or radiological evidence, AND
• A History of travel from countries in or near the Arabian Peninsula within 14 days before symptoms onset, or close contact with a asymptomatic 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 History of being in healthcare facility as a patient, worker, or visitor in the Republic of Korea within 14 days before symptoms onset, 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 in the US.

Milder illness

• Fever and symptom of respiratory illness not necessarily pneumonia (cough, shortness of breath) AND a history of being in a healthcare facility as a patient, worker or visitor within 14 days before symptoms onset in a country or territory in or near the Arabian Peninsula in which recent healthcare-associated cases of MERS have been identified
• Fever or symptoms of respiratory illness not necessarily pneumonia (cough, shortness of breath) AND close contact with a confirmed MERS case while the case was ill.

The above criteria serve as guidance for testing; however, patients should be evaluated and discussed with public health departments on a case-by-case basis if their clinical presentation or exposure history is equivocal (e.g., uncertain history of health care exposure).

Confirmed Case

A confirmed case is defined when a person has laboratory confirmation of MERS-CoV infection. Confirmatory laboratory testing requires a positive PCR on at least two specific genomic targets or a single positive target with sequencing on a second.

Probable Case

A probable case is defined when a PUI has absent or inconclusive laboratory results for MERS-CoV infection who is a close contact of a laboratory-confirmed MERS-CoV case. Examples of laboratory results that may be considered inconclusive include a positive test on a single PCR target, a positive test with an assay that has limited performance data available, or a negative test on an inadequate specimen.

Notes:

Countries considered in the Arabian Peninsula and neighboring 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: 

• Being within approximately 6 feet (2 meters) or within the room or care area for a prolonged period of time (e.g., healthcare personnel, household members) while not wearing recommended personal protective equipment (i.e., gowns, gloves, respirator, eye protection, or
• Having direct contact with infectious secretions (e.g., being coughed on) while not wearing recommended personal protective equipment (i.e., gowns, gloves, respirator, eye protection.
• 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.