ICUs can be hotbed for antibiotic resistance

Overuse of drugs one key reason

With trends pointing to reduced lengths of patient stay and increasing care delivered in outpatient settings, it would seem that antibiotic resistance issues and nosocomial infections would diminish accordingly in the hospital setting. On the contrary, hospitals - especially ICUs - are hotbeds for resistant pathogens, and nosocomial infections have increased dramatically despite the prevailing demographics in health care, says William Jarvis, MD, chief of the investigation and prevention branch of the Centers for Disease Control and Prevention hospital infections program.

"Amazingly, when we control for the number of patients admitted and their length of hospital stay, the overall nosocomial infection rate in hospitals increased by 36% between 1975 and 1995," he said recently at a public health training network satellite broadcast on antibiotic resistance. "Many of these infections were caused by multidrug-resistant pathogens. This increase in nosocomial infections has occurred despite the best infection control programs in the world."

The rise in the infection rate reflects the increasing severity of illness of hospitalized patients and the number of invasive devices used on those patients in acute care facilities, he noted. Moreover, the proportion of hospitalized patients in intensive care units continues to increase.

"We know that ICU patients are the most likely group to receive antimicrobials and are at much greater risk for acquiring and transmitting antimicrobial-resistant pathogens," Jarvis said.

Indeed, Jarvis cited the following contributing factors for the prevalence of antibiotic resistance in hospitals:

· The acute care setting is unique because antimicrobial use is very prevalent.

In some studies, as many as 40% to 50% of hospitalized patients received at least one antimicrobial. In some populations, including some adult, pediatric, or neonatal intensive care units, nearly 100% of patients receive at least one antimicrobial during their hospitalization.

· A wide variety of antimicrobials are available in a hospital, and most of these are given intravenously at high doses.

· Transmission of antimicrobial-resistant pathogens occurs within and between health care facilities.

Patients are moved to different areas of the hospital, or they may be transferred from or to another health care facility which is experiencing problems with antimicrobial-resistant pathogens. Health care workers can also contribute to transmission of pathogens by failing to comply with infection control practices, especially hand washing.