FDA approves test for anthrax in lab cultures

Dec 17, 2003 (CIDRAP News) – The Food and Drug Administration (FDA) recently approved a new test that clinical laboratories can use to help identify anthrax in cultures of bacteria from people potentially infected with the pathogen.

The Redline Alert test for Bacillus anthracis can be done in about 15 minutes and does not require specially trained personnel or special instruments, the FDA announced in a Dec 9 news release. The test is made by Tetracore, Inc., of Gaithersburg, Md. The FDA said other tests now in use may require overnight testing or special equipment or training.

The test involves adding cultured cells to a cassette that contains immunologic reagents, the FDA said. If a certain protein found in B anthracis is present, a light red or pink line appears in the cassette. The protein is also found in some other microbes, but those organisms usually do not resemble B anthracis in lab cultures.

If the test is positive and if other culture characteristics are consistent with anthrax, the person from whom the cells were taken is probably infected with anthrax, the FDA said. "Other testing is needed to positively identify anthrax," the agency said. "A negative result with the new test cannot rule out anthrax because in rare cases certain B. anthracis organisms may not give a positive result."

The FDA approved the test on the basis of studies in which Tetracore cultured 145 B anthracis samples from around the world. The test yielded true-positive results in 143 cases.

The test is intended only for laboratories whose staff members are trained in microbiological culture procedures and use biosafety level 2 practices, the FDA said.

See also:

FDA news release
http://www.fda.gov/bbs/topics/NEWS/2003/NEW00992.html