Antimicrobial resistance has been demonstrated in all classes of antimicrobial agents. Morbidity and mortality rates from infections related to resistant organisms are high, especially in the very young, the elderly and immunocompromised persons. Virk and Steckelberg review this serious global problem.

Contributing factors for the increase in antibiotic resistance include the inappropriate use of antibiotics, an increased number of immunocompromised patients, poverty, use of antibiotics in animal husbandry and fisheries, international travel and prolonged survival of debilitated patients. Practice habits of physicians in the outpatient setting contribute substantially to the emergence of resistant strains. Most antibiotic prescriptions are written for outpatients. Estimates are that approximately 50 percent of antibiotic prescriptions for outpatients are intended for inappropriate indications such as colds, upper respiratory tract infections and bronchitis.

The accompanying table summarizes guidelines for prevention of antimicrobial resistance in hospitals. These guidelines were issued in 1997 by the Society for Healthcare Epidemiology of America and the Infectious Diseases Society of America. Preventive measures such as sanitation, hygiene, improved standards of living and nutrition must be instituted in all countries to control the spread of resistant organisms. Methods of reducing the inappropriate use of antimicrobial agents include the following: changing empiric therapy to narrow-spectrum therapy according to culture and sensitivity results; providing optimal dosing; using antibiotics for a shorter duration; using local susceptibility patterns to aid in appropriate empiric therapy; and using antibiotics for specific indications only.