Tougher Germs, at Home and On the Farm.

• Author: Hwang, Ann

Almost all major infectious diseases are becoming resistant to existing medicines, according to a June 2000 World Health Organization report (see "Super-bugs Arrive," March/April 1999). In the United States alone, an estimated 14,000 people are dying each year from drug-resistant microbes that infect them in hospitals. Much of this resistance is caused by inappropriate medical use of antibiotics. (In the developing world, sick people may be able to afford only partial treatment--enough to kill susceptible germs while leaving the hardier ones to thrive. In the developed world, overuse of drugs is speeding up the rate at which microbes adapt, just as indiscriminate use of insecticides encourages the development of tougher bugs.) In addition to these medical problems, there is growing evidence of resistance caused by the use of antibiotics in agriculture and by antimicrobial consumer products

Sales of antimicrobial hand soaps, dishwashing liquids, and other such products are booming, particularly in the United States, where the market for antimicrobial and disinfectant chemicals is expanding at 3.6 percent annually and is expected to reach $620 million by 2003. Despite manufacturers' success in capitalizing on consumer fear of germs, there is little evidence that any of their products actually prevent infection. The U.S. Environmental Protection Agency, which regulates U.S. sales of cutting boards, dish sponges, and other products treated with antimicrobials, maintains that it "has seen no evidence that these products prevent the spread of germs and bacteria in humans." In April 1997, the EPA fined Hasbro, the manufacturer of Playskool toys, for claiming that an antimicrobial agent in its products helped to protect children's health.

In scientific studies, antimicrobial personal-care products seem to fare no better than the cutting boards. The American Medical Association recently reviewed the studies conducted thus far and found no evidence that antimicrobial soaps, lotions, mouthwashes, or other such products confer any infection-fighting benefit. What the AMA did find was evidence of growing resistance to many common antimicrobial agents. Although these antimicrobials are too toxic to be taken as drugs, some research suggests that antimicrobials could promote "cross resistance": some strategies that bacteria adopt to ward off antimicrobials, such as chemical pumps that eliminate the deadly substances, also work against antibiotics.

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