BAY AREA USING FIRM'S TB TESTING BLOOD REPLACES SKIN PRONGS.

Byline: Daily News

VALENCIA - A new tuberculosis test developed by a local company that is aimed at replacing the century-old prickly skin test was introduced Monday at San Francisco County clinics, officials said.

Valencia-based Cellestis Inc.'s QuantiFERON-TB Gold has been adopted by the San Francisco County Health Department as part of a strategy to prevent further spread of the respiratory disease, the company said in a statement.

The move comes after the test, developed by the company's Australian researchers, qualified for Medi-Cal reimbursement. The one-step blood test detects immune responses to proteins associated with mycobacteria tuberculosis, and received federal Food and Drug Administration approval in December.

``Medi-Cal reimbursement of QuantiFERON-TB Gold is a tremendous achievement because it opens the door for wider adoption in California, a state with several TB hot spots,'' Tony Radford, chief executive office of Cellestis, said in a statement. ``The urgent need for a new tool to more accurately identify individuals who are infected and those who are at risk of developing tuberculosis has been reinforced by a state that is a bellwether for the rest of the country.''

While the number of tuberculosis cases in the United States is slowly decreasing, TB is resurfacing in several metropolitan areas, such as San Francisco, where 231 active cases were reported to the federal Centers for Disease Control and Prevention in 2003.

``With large numbers of immigrants and high-risk patients served by San Francisco's county health department, a more accurate test for TB has long been awaited,'' Dr. Masae Kawamura, TB controller for the city of San Francisco, said in a statement. ``QuantiFERON-TB Gold will eliminate the waste of precious health resources from inaccurate skin tests and improve public safety by preventing unnecessary treatment.''

The existing tuberculin skin test developed in the 1890s uses injections delivered through six tiny prongs, usually on the forearm, and requires patients to return to their physician to interpret results. They vary from no reaction to varying severity of a rash or bumps on the skin, symptoms that must be studied by a medical professional to determine whether the patient has the disease.

Compared with the skin test, the QuantiFERON test is unaffected by subjective interpretation, previous vaccinations or unrelated mycobacteria, officials said. Clinical data show a 99 percent accuracy rate.

A 2003 study on infection control and hospital epidemiology found that running a TB control program using the skin test cost up to $362 per employee, 98.5 percent of the total cost being spent on medical staff time and on correcting false-positive results. False positives are as high as 50 percent among U.S. patients.

The company's parent, Cellestis Ltd., is a publicly traded company on the Australian Stock Exchange. It developed QuantiFERON based on tests used to detect tuberculosis infection in cattle.