The Food and Drug Administration (FDA) cleared for marketing the first rapid laboratory test for a life-threatening invasive fungal infection that occurs in leukemia patients, organ and bone marrow transplant patients, and patients whose immune systems are compromised by illness or chemotherapy. The test will allow doctors to diagnose invasive aspergillus infection quicker and begin treatment with anti-fungal drugs sooner.

The new test, the Platelia Aspergillus EIA, manufactured by Bio-Rad Laboratories, of Redmond, Washington, detects Aspergillus galactomannan antigen in blood, and is a good indicator of invasive infection.

Results are available in about three hours. By comparison, the standard culture method of testing for aspergillus takes a minimum of four weeks before results are available.

"Earlier detection means earlier and more accurate intervention with life-saving treatment for these critically ill patients," said FDA Commissioner Mark B. McClellan, M.D., Ph.D. "One of FDA's goals is to help make new products that improve medical care available to the public as quickly as possible."

FDA cleared the product based on clinical studies of the test's performance at three cancer centers that showed the test could accurately identify the presence or absence of the aspergillus antigen.

The centers tested 1,890 blood samples collected from 170 patients. Thirty one patients had proven or probable invasive aspergillosis. The new test correctly identified 25 of the 31 people who had aspergillus antigen (80.7 per cent sensitivity). When 148 patients without signs or symptoms of invasive aspergillosis were tested, the test correctly identified 132 of the 148 (89.2 per cent specificity) as not having the antigen.

Although the number of invasive aspergillus cases in the United States is estimated to be only a few thousand per year, the disease is very serious and has a mortality rate of 50 per cent-100 per cent.