A Growing Threat to Public Health

    Each year, nearly 2 million patients in the United States get an infection as a result of receiving health care in a hospital. These hospital-acquired infections are often difficult to treat because the bacteria and other microorganisms that cause them frequently are resistant to antimicrobial drugs.
    Bacteria, fungi, and even viruses can become resistant to drugs. However, bacteria cause most of the drug-resistant problems in hospitals. Bacteria can become resistant to antibiotics in a variety of ways. And once a particular type of bacteria has developed resistance to a drug, it can pass on this resistance to other types of bacteria.
    Overall, 70% of the bacteria causing such infections are resistant to at least one of the drugs most commonly used to treat these infections. In some cases, these organisms are resistant to all approved antibiotics and must be treated with experimental and potentially very toxic drugs.
    The more often a drug is used, the more likely bacteria are to develop resistance to it. For this reason, and to combat the problem of drug-resistant bacteria, CDC has developed recommendations to help ensure that drugs are prescribed only when appropriate. These recommendations, together with other CDC guidelines for infection control, are helping to limit the spread of drug-resistant infections in the nation's hospitals.

What has been the impact of antibiotic resistance on the problem of hospital-acquired infections?
     Antibiotic resistance is a major contributor to the disease, death, and costs resulting from hospital-acquired infections. Unfortunately, we don't yet have precise numbers. There is a great need for studies in this area. One report placed the annual cost of antimicrobial resistance among a single pathogen (Staphylococcus aureus) at $122 million.

What's being done about this?
    CDC and other healthcare organizations, such as the Society for Healthcare Epidemiology of America, the Association for Professionals in Infection Control and Epidemiology, the Infectious Diseases Society of America, and the American Academy of Pediatrics, are working to improve antimicrobial prescription practices. For example, in late 1997 CDC sponsored a national videoconference for healthcare workers to improve the use of vancomycin, a first-line drug used to combat serious staphylococcal and enterococcal infections. Another videoconference on antimicrobial use was held in late1998. And we're making our guidelines available in new ways, e.g., over the Internet.

Do doctors overprescribe antibiotic drugs in hospital and health care settings?
    CDC and other healthcare organizations have developed guidelines for the use of antibiotics in hospitals; however, some research indicates that antibiotics are being used more than the guidelines recommend. For example, one recent study indicated that as much as 60% of the hospital prescriptions for one of these drugs, vancomycin, are not in accordance with the guidelines.

What are the most common patient mistakes with antibiotics?
    Asking for antibiotics they don't need, e.g., as treatment for viral infections, such as colds, which don't respond to antibiotics. Not taking antibiotics as prescribed, especially stopping before the prescription runs out (thus, they may not kill all the infecting organisms and they leave the most resistant ones behind to continue to grow). Saving antibiotics and later self-prescribing them.

What should a hospital do to address the problem of antimicrobial resistance?
    The hospital should monitor antibiotic use and resistance, provide guidelines for antimicrobial use and for preventing the spread of resistant bacteria within the hospital, and monitor compliance with these guidelines.

Are most doing this?
    Because there are no current standards for antibiotic use such as those the Joint Commission on Accreditation of Healthcare Organizations sets for infection control, we don't have a clear picture on this. But we think the percentage of hospitals with adequate programs for monitoring antimicrobial use and resistance is much smaller than the percentage with effective infection control programs.

June 1999

Division of Healthcare Quality Promotion
National Center for Infectious Diseases
Centers for Disease Control and Prevention
Atlanta, GA