Drug-resistant pathogens: Can one approach fit all?
CDC struggles to unify isolation precautions
Developing a unified approach to multidrug-resistant organisms (MDROs) is emerging as the most difficult and controversial aspect of an ongoing revision of patient isolation guidelines, a key advisor to the Centers for Disease Control and Prevention (CDC) reported.
The new patient isolation guidelines are under development by the CDC’s Healthcare Infection Control Practices Advisory Committee (HICPAC). The "Guideline for Prevention of Transmission of Infectious Agents in Health Care Facilities" is expected to be finalized in 2003, but remains very much "a work in progress," HICPAC member Jane Siegel, MD, said recently in San Diego at the Interscience Conference on Antimicrobial Agents and Chemotherapy (ICAAC).
"[MDROs] are certainly the most challenging aspect of this guideline," said Siegel, a professor of pediatrics at the University of Texas Southwestern Medical Center in Dallas. "In the last decade with MRSA [methicillin-resistant Staphylococcus aureus], we’ve gone from about 20% of Staph aureus being resistant to methicillin to now 55%. And with VRE [vancomycin-resistant enterococci], [we have gone] from 1% to now 26%. There’s significant morbidity, mortality, and cost that’s been demonstrated for these resistant organisms."
While understandable attention has been focused on MRSA and VRE, there are many other resistant pathogens emerging that are presenting problems for the health care system, she said.
"Our goal in this guideline is to provide a unified approach to management of MDROs based on the knowledge of the epidemiology, effective interventions, and risk assessment within health care facilities — without having necessarily a specific recommendation for each MDRO as it emerges," she said. "This is very controversial, and I know that’s an understatement."
The critical question is whether the same recommendations developed in reaction to outbreaks still apply to all settings and all patients, she said. In revising the 1996 CDC isolation guidelines, HICPAC is trying to adopt a more generic infection control approach to drug-resistant organisms rather than issuing guidance for individual pathogens. While there still will be enhanced measures for airborne, contact, and droplet precautions, the emphasis will be on standard precautions for all patients, she said.
"This guideline reaffirms standard precautions that was first described in 1996 as the foundation for preventing transmission of infectious agents among patients and health care workers in all settings," Siegel said. "Our goal is to provide epidemiologically sound evidence-based recommendations and to have a user-friendly communication. We know as we extend the scope across the continuum of care, we have a very heterogeneous group of providers who are charged with the responsibility of implementing infection control programs." Standard precautions evolved from old universal precautions and body substance isolation systems, which considered blood, body fluids, secretions (except sweat), nonintact skin, and mucous membranes as containing transmissible infectious agents regardless of the patient diagnosis.
"There are different elements of standard precaution, hand hygiene being the basic foundation and probably the most important to practice consistently," she said. "What standard precautions are not: Observing the same practices for everyone does not mean doing nothing for anyone."
While the more aggressive strategies (i.e., active surveillance cultures to detect the patient reservoir) remain controversial, it appears HICPAC is ready to endorse a few basic measures against MDROs for all health care facilities.
"All facilities need to have some surveillance of their clinical antimicrobial susceptibility summary reports by location and risk," Siegel said. "I think all facilities need a judicious-use-of-antimicrobial-agents program. Standard precautions must be emphasized, especially hand hygiene with monitoring of health care worker adherence. And we need to pay attention to devices. We need to have standardized protocols that are implemented and removal of devices when they’re no longer needed."
The guidelines will recommend that most non-hospital settings do a risk assessment to determine their approach to MDROs.
"The acute care [hospitals] with complex ICUs are high risk and would probably benefit by adopting a complete [MDRO] program," she said. "In other settings, the program would really need to be according to risk assessment." The risk assessment would be based on such factors as the patient population, the inability to contain drainage or secretions, trends in the rate of transmission of target organisms, adherence or effectiveness of infection control measures, antimicrobial usage patterns, and resources. "Resources not only in terms of dollars but in terms of human resources," Siegel said. "If we devote the human resources in infection control to a massive, aggressive campaign to decrease VRE colonization and disease, what will [those resources] be taken away from? And what other things will be happening in the absence of attention to that? And also, what tremendous laboratory [resources] will be required?"
Reflecting an increasing trend in HICPAC guidelines, the isolation measures will come with specific recommendations aimed at health care administration. "One [recommendation] is to incorporate the concept of infection control and prevention of transmission of infections into the organization’s safety culture," she said. "That is part of ensuring a safe work environment, a blame-free environment; and a safety culture [also] has been linked to lower blood exposures [to workers]." By the same token, the guidelines will emphasize the role of inadequate nurse staffing in the occurrence of nosocomial infections. "There are actually many studies now that have demonstrated that there’s clearly an increased risk of health care-associated infections when there are conditions of understaffing," Siegel told those attending ICAAC.