Diagnosis of Severe Acute Respiratory Syndrome(SARS)
SARS-CoV is detected using enzyme-linked immunoassays (EIA) or reverse transcriptase polymerase chain reaction (PCR) tests, which are available through the CDC. These tests are performed on respiratory secretions or blood.

These tests are performed only when the patient's history makes SARS likely and usually in consultation with infectious-disease doctors, public-health authorities, and the Centers for Disease Control and Prevention. If a test is positive, it will be confirmed by the CDC. Other tests may be abnormal, but they are not specific for SARS. The chest X-ray shows pneumonia, which may look patchy at first. White blood cells and platelet (clotting cell) counts in the blood are usually decreased.

SARS should be considered in people with the appropriate symptoms who work with SARS-CoV in a laboratory or who have recent exposure to infected people or mammals in Southern China. No human cases of SARS have been reported since 2004 in the United States, so it is extremely unlikely that a patient in the U.S. will have SARS without a history of such exposure. It is possible, however, that a new outbreak might occur. Therefore, SARS (along with other similar viruses) should also be considered when there is a cluster of unusually severe pneumonia that has no other explanation.