Quest Diagnostics Incorporated , the nation's leading provider of diagnostic testing, information and services, today announced that it has developed a diagnostic test to detect the avian influenza virus and will participate in the government's preparedness efforts to provide rapid diagnosis and early surveillance of an outbreak, should the need arise.

Quest Diagnostics has notified physicians and hospitals that it has begun to offer a gene-based screening test it developed to identify the H5N1 strain of Influenza A virus, the virus that is responsible for causing "avian flu" in birds and some humans in certain parts of the world. The test is intended to help physicians screen patients with a range of flu-like symptoms who may have been exposed to the virus. Testing is performed on respiratory samples, which include sputum, swabs and bronchial washes.

Positive results of the screening test would be considered a "presumptive identification" of avian flu until confirmed by the U.S. Centers for Disease Control (CDC) or other public health laboratory.

About Quest Diagnostics

Quest Diagnostics is the leading provider of diagnostic testing, information and services that patients and doctors need to make better healthcare decisions. The company offers the broadest access to diagnostic testing services through its national network of laboratories and patient service centers, and provides interpretive consultation through its extensive medical and scientific staff. Quest Diagnostics is a pioneer in developing innovative new diagnostic tests and advanced healthcare information technology solutions that help improve patient care. Additional company information is available at: http://www.questdiagnostics.com/.

The statements in this press release which are not historical facts or information may be forward-looking statements. These forward-looking statements involve risks and uncertainties that could cause actual results and outcomes to be materially different. Certain of these risks and uncertainties may include, but are not limited to, competitive environment, changes in government regulations, changing relationships with customers, payers, suppliers and strategic partners and other factors described in the Quest Diagnostics Incorporated 2004 Form 10-K and subsequent filings.

SOURCE: Quest Diagnostics Incorporated

CONTACT: Laure Park, Investors, +1-201-393-5030, or Jennifer Somers, or
Gary Samuels, both for Media, +1-201-393-5700, all of Quest Diagnostics
Incorporated

Web site: http://www.questdiagnostics.com/