Infection Control: Focus on Prevention

APRIL 01, 2006
Rosemary Cross, PharmD, BCPS

Despite the advent of newer antibiotics and advancements in technology, nosocomial infections remain a major problem in today's health care system. The Centers for Disease Control and Prevention (CDC) estimates that approximately 2 million hospitalized patients each year acquire infections that were not related to the condition for which they were admitted.1 In general, these types of health care- associated infections can be reduced by appropriate infection control, such as good hand washing, the use of protective barriers, and contact isolation protocols.2,3

The Joint Commission on Accreditation of Healthcare Organizations (JCAHO) published new standards of infection control in 2005, citing increasing antimicrobial resistance and emerging pathogens as a major concern. The JCAHO standards expect institutions to implement infection-prevention and control processes, to identify areas of risk for transmission of infection, to utilize surveillance data effectively, and to educate practitioners to comply with their institution's infection-control procedures.2

Antimicrobial Resistance

Hospitals worldwide are faced with the increasingly rapid emergence and spread of antibiotic-resistant bacteria. Both resistant gram-positive and gramnegative bacteria are reported to be important pathogens of hospital-acquired infections. Among gram-positive bacteria, methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin- resistant Enterococci (VRE) are common and problematic infections in the hospital setting. MRSA infections have increased dramatically within hospitals and the community; however, ample treatment options have become available in recent years.4 VRE infections have increased among intensive care patients over the last several years—perhaps due to high antimicrobial usage in this setting, which has resulted in increased hospital morbidity rates from this type of bacteria.5

Multidrug-resistant gram-negative infections are on the rise, including strains of Pseudomonas, Acinetobacter, and extended-spectrum beta-lactamases Klebsiella and Escherichia coli. Minimal treatment options exist for these resistant pathogens, forcing clinicians to utilize older antimicrobials associated with high toxicity. Clostridium difficile is another highly transferable pathogen; most institutions require infected patients to remain in isolation. Fortunately, there are methods to prevent the spread of many of these infections.4

Preventive Measures

Hand Hygiene

Since the early 1800s, good hand hygiene has been recognized as the single best method to prevent the spread of nosocomial infections. 6 Despite this fact, many health care providers are not compliant with hand-washing policies.7 The authors of many studies conducted on handwashing compliance report that health care practitioners comply with appropriate hand hygiene only 25% to 50% of the time.8,9 In October 2002, the CDC released the "Guideline for Hand Hygiene in Health-Care Settings," which recommends washing with soap and water when hands are visibly dirty. If hands are not visibly soiled, practitioners should use an alcohol-based or other antiseptic rub—chlorhexidine gluconate, iodophors, parachlorometaxylenol, or triclosan.6,10 Of note, none of the antiseptic hand rubs are reliably active against spore-forming bacteria such as C difficile and Bacillus anthracis. Health care practitioners must remember to wash their hands thoroughly with soap and water to help physically remove these spores from their hands.8,10 Regardless of the method, hands must be properly decontaminated immediately before and after each direct patient contact.

Personal Protective Equipment (PPE)

In addition to hand washing, the use of gloves, gowns, and masks has been shown to reduce the transmission of specific pathogens.8 The selection of PPE should be based on an assessment of the risk for contamination of the health care worker's clothing and skin by the patient's blood, body fluids, or other secretions. Gloves should be worn for all invasive procedures and for general contact with areas of the patient that are normally sterile. Gloves must be changed between patients and disposed of as clinical waste. Types of gloves that may be worn include vinyl, nitrile, or latex, depending on the patient's allergies. Gloves do not substitute for good hand-hygiene practices, because the hands must be decontaminated upon removal of the gloves to ensure no transmission of infections.11

Full-body gowns should be worn when there is a risk of extensive splashing of blood or other potentially infectious material onto the health care practitioner. Masks and protective eyewear should be worn if there are likely to be splashes or sprays of infectious materials into the health care worker's face during procedures or other patient activities. Of note, surgical masks do not provide adequate protection against hazardous airborne diseases. In cases of known or suspected tuberculosis or infection with rubeola and varicella viruses, respirators or N95 masks should be worn prior to entering a patient's room. It is recommended that these materials be readily available outside a patient's room to encourage compliance with infection- control standards.9

Isolation/Contact Precautions

Contact precautions are designed to reduce the risk of transmission of a known organism by limiting direct or indirect contact. All persons entering an isolation room must put on gowns, gloves, and/or masks prior to entering, even if they are not expected to come in contact with infectious material. Although it has been argued that gown use is ineffective as a barrier for infections, required use may reduce bacterial spread by increasing awareness of infection-control measures for those patients on isolation precautions.9 Infections caused by the following bacteria are commonly put on contact precautions: VRE, MRSA, C difficile, and multidrug-resistant gramnegative bacteria.12

Antibiotic Restrictions/Rotations

The overuse of broad-spectrum antibiotics is a problem that can increase antibiotic resistance in many hospitals. Various strategies for improving antibiotic utilization have been proposed, because inadequate antibiotic treatment has been associated with increased hospital mortality rates, prolonged hospitalization, and increased overall health care costs.3 At a minimum, clinicians should make sure that antibiotics are dosed appropriately, at the correct frequency, and that they provide adequate coverage for suspected organisms. Some institutions have employed antimicrobial formularies to restrict antibiotic drug choices, and others have attempted a system of antibiotic-class rotation for reducing the emergence of antimicrobial resistance. Both methods appear to be effective for limited periods in closed environments such as intensive care units.6,13

In conclusion, proper infection control needs to include education of patients, their caretakers, and health care personnel about good preventive measures.14 These measures should include appropriate hand hygiene, the use of PPE or isolation when indicated, and judicious use of antibiotics. Hospitals should incorporate ongoing measurement of performance and adherence to infection-control procedures through surveillance systems, with health care providers held accountable for noncompliance with standards. Only then can clinicians attempt to decrease the incidence of health care-associated infections.

Dr. Cross is a transplant clinical pharmacist with Piedmont Hospital in Atlanta, Ga.

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