Food Safety

Although the U.S. food supply is reportedly among the safest in the world, the Centers for Disease Control and Prevention estimate that as many as 76 million cases of illness and as many as 5,000 deaths result from foodborne diseases each year. The challenge of ensuring the safety of the food supply is becoming even more difficult as Americans eat more foods imported from abroad. Such imports have more than doubled in the last seven years. This report examines the Food and Drug Administration's (FDA) use of faster technologies--known as rapid tests--to screen and identify potentially unsafe imported foods, particularly at ports of entry, before they make it to grocery store shelves. Rapid tests can generally be completed in a day or two, offering a faster, cheaper, and more convenient alternative--without sacrificing reliability--to conventional laboratory tests that can take considerably longer to identify disease-causing pathogens in foods. This report describes (1) the rapid tests used to screen foods for pathogens, such as bacteria, parasites, and viruses; (2) FDA's use of these tests, particularly at ports of entry; and (3) the factors that may limit FDA's greater use of rapid tests for foodborne pathogens.

GAO noted that: (1) more than 150 rapid tests may be used to screen foods for bacterial pathogens such as Salmonella, according to FDA and scientific literature; (2) many of these tests have been borrowed from clinical settings, although their use with food requires a preparation step of 24 hours or more to cause a bacterial pathogen to reproduce to detectable levels; (3) rapid tests employ a wide variety of technologies; (4) some measure chemical substances unique to a bacterium, while others identify a specific genetic sequence associated with a bacterium or a toxin it produces; (5) rapid tests to identify parasites and viruses in foods do not exist because of technological limitations; (6) FDA uses dozens of rapid tests to screen food samples for bacterial pathogens; (7) FDA's decision to use a rapid test is based on such factors as the agency's testing priorities and needs and the cost and reliability of available tests; (8) FDA uses rapid tests in its laboratories but not at food inspection sites such as ports of entry; (9) testing occurs in laboratories primarily because of the need to enrich bacterial pathogens in foods, a process that should be done under the controlled conditions laboratories provide; (10) in addition, although some rapid tests come in self-contained kits, others require specialized equipment and materials found only in laboratories; (11) furthermore, a laboratory technician, such as a microbiologist, may be needed to administer or interpret the results of some rapid tests; (12) a FDA research plan for fiscal year 1999 through 2001 includes provisions for developing a number of additional rapid tests; (13) several factors can limit FDA's expanded use of rapid tests for foodborne pathogens; (14) various ingredients or additives in certain foods may interfere with a test's reliability; (15) in addition, with regard to fresh foods such as fruits and vegetables, harmless bacteria in the food may mask the presence of pathogenic bacteria; (16) furthermore, rapid tests, like conventional laboratory tests, are subject to sampling limitations; and (17) specifically, the food samples tested may not be representative of the health risks of an entire food shipment or of all shipments from a particular exporter.