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Middle East Respiratory Syndrome (MERS) is viral respiratory illness first reported in Saudi Arabia in 2012.
It is caused by a coronavirus called MERS-CoV. Most people who have been confirmed to have MERS-CoV
infection developed severe acute respiratory illness. They had fever, cough, and shortness of breath.
About 30% of people confirmed to have MERS-CoV infection have died.

Case Definitions

Patient Under Investigation (PUI)

A patient under investigation (PUI) is a person with the following characteristics:

A. Fever (≥38°C, 100.4°F) 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 Peninsula1 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 Peninsula1 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. OR

B. Close contact with a confirmed or probable case of MERS while the case was ill AND o fever (>100°F) or symptoms
of respiratory illness within 14 days following the close contact. (This is a lower threshold than category A.)
PUIs should be evaluated in consultation with the state and local health departments. For more information,
see CDC’s Interim Guidance for Health Professionals.

Confirmed Case
A confirmed case is a person with laboratory confirmation of MERS-CoV infection.

Probable Case
A probable case is a PUI with absent or inconclusive laboratory results for MERS-CoV infection who is a close contact
of a laboratory-confirmed MERS-CoV case.

MERS Infection Control Guidance