Improper use of antibiotics favors the development of resistance, and the current widespread existence of resistant bacteria testifies to the carelessness with which these life saving drugs have been used. For example, since antibiotics are powerless against viruses, the common practice of prescribing these drugs for a viral infection merely affords stray bacteria the opportunity to develop resistance.
Another example of improper use is the common tendency of patients to stop taking an antibiotic when they feel better instead of continuing for the full prescribed course. The first few days’ dose may have killed off all but a few bacteria, the most resistant, which may then survive and multiply, becoming much more difficult to control. In some countries, antibiotics are available without a prescription, increasing the likelihood that they will be used improperly. Diseases that went unnoticed in animals but have spread to humans include AIDS, Ebola, avian influenza, and SARS.
Other priorities that the Institute of Medicine has identified for controlling emerging infections include reducing inappropriate use of antibiotics by banning their use for growth promotion in animals and by developing improved diagnostic tests for infectious diseases so that antibiotics are not used for viral diseases. The Institute of Medicine also recommends developing new vaccines, new antimicrobial drugs, and measures aimed at vector-borne diseases.