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Infection Control and Healthcare Keith F. Woeltje, M.D., Ph.D. Dr. Woeltje is Associate Professor of Medicine, Infectious Diseases, Washington University School of Medicine, St. Louis, MO. Healthcare-associated infections (HAI) -- that is, infections that are contracted during medical treatment -- are not a widely or easily discussed subject. Neither patients nor doctors like to think about them because hospitals and other health care facilities are places we go to get well, not to get sicker. Somewhere between 5 and 15% of patients who spend a significant amount of time in the hospital acquire some type of infection there. Medicine has traditionally used mysterious, unevocative terms for this phenomenon such as iatrogenic ("due to medical treatment") or nosocomial ("hospital-acquired") infection. Only if you are a medical professional or fluent in ancient Greek would the meaning of these words be clear. According to studies in the U.S., an infection develops in about 1 in 20 hospitalized patients, an estimated 1.7 million patients per year.1 Infections acquired during home care or from outpatient treatment get less attention but certainly occur. Why do HAI happen? There are many reasons, not all of which are preventable. After all, hospitals are full of severely ill patients with weakened immune systems; these people are at increased risk for any infection. On the bright side, knowledge of how to prevent HAI is steadily improving and medical attitudes toward HAI are changing. In the past, HAI were assumed to be an inevitable cost of doing business. But as many hospitals have succeeded in driving their rates of HAI lower than was ever thought possible, it has been recognized that the vast majority of HAI can be prevented. HAI rates will never reach zero. But already, in many medical centers, rates of some HAI, such as catheter-associated bloodstream infections (CABSI) and ventilator-associated pneumonia (VAP), are approaching zero. For patients and their families, knowledge of HAI and the types of precautions used in hospitals can make you a more educated healthcare consumer who is better able to notice and report infections or risky practices and better manage infection control at home. What Are HAI? A healthcare-associated infection is any infection that develops during or as a result of medical treatment. Programs designed to prevent or control HAI tend to focus on a short list of the most common and most dangerous infections, with higher priority given to HAI which are more preventable. In some states, keeping track of particular HAI may be mandated by law and may be required to be reported to state authorities and eventually the CDC (Centers for Disease Control).2 Device-Associated Infections One of the main sources of infection are medical devices such as catheters, ventilators, feeding tubes and IV lines, mainstays of modern medical care. While they certainly save lives, they also significantly increase the risk of infection. These devices are used a great deal in ICUs,. In addition to their increased exposure to these devices, ICU patients tend to be at higher risk for infection simply because they are very ill. Catheters can cause bloodstream infections and urinary tract infections. Ventilators can cause pneumonias. Surgical Site Infections Infections can also occur at surgical sites. Coronary-artery bypass graft surgeries (CABGs) and hip and knee joint replacements are examples of surgeries that are commonly tracked for infection rates by hospitals. Prevention In addition to tracking infections, hospitals have begun to institute a variety of procedures to lower the rates of HAIs. Hand Hygiene It may sound simple, but good hand hygiene is the single most important way to fight HAI. Unfortunately, despite the widespread lip service paid to the need for good hand washing, the reality is that healthcare providers, like the rest of us, are not very conscientious about washing hands. Except in certain areas -- in operating rooms 100% compliance is the norm -- surveys report that healthcare workers wash their hands less than 40% as often as they should. With the introduction of alcohol-based hand-rub products, the broader term "hand hygiene" has been introduced to cover both traditional hand-washing with soap and water and hand disinfection with an alcohol-based product. Because alcohol-based hand-rub dispensers can be placed in many more locations than sinks, they make it much more likely that healthcare workers will actually perform hand hygiene. Alcohol-based hand-rubs take far less time than traditional soap-and-water washing. Table 1 shows the CDC-recommended indications for hand hygiene.3 Hand washing with soap and water should be done whenever the hands are visibly soiled. Otherwise, use of an alcohol-based product for hand hygiene is acceptable. Both the CDC and the World Health Organization have made improved hand hygiene a major goal. Table 1. Times When Medical Staff Should Use Hand Hygiene.
Standard Precautions There are a number of precautions that can prevent the spread of infection in healthcare settings.4 These precautions should be followed at all times for all patients. In addition to good hand hygiene, gloves should be worn whenever there may be contact with any damaged skin or bodily fluid. Protective equipment should be removed and disposed of before leaving the patient's room so that common areas are not inadvertently contaminated. Transmission-based Precautions Standard precautions cannot prevent the spread of all pathogens. For certain diseases, additional precautions are necessary. Your individual hospital's Infection Prevention and Control Department should be contacted for specific details. Transmission-based precautions include: Droplet Precautions These precautions should be implemented when patients are known or suspected to have an illness spread by large respiratory droplets, such as N. meningitides, the cause of meningococcal meningitis (the most common form of bacterial meningitis), or influenza. Because the infectious particles are not suspended in the air for long periods, special air handling (see below) is not necessary. A surgical mask or isolation mask is considered to be sufficient respiratory protection from these illnesses. Airborne Precautions Because the infectious particles in airborne-spread diseases can remain suspended in air for long periods of time and can travel long distances, so-called special air handling is required for patients with these infections. Patients must be isolated in airborne infection isolation rooms (AIIR, or negative-pressure ventilation rooms). Air pressure in these rooms is kept lower than the air pressure in the adjacent hallway. Thus, air comes in from the hallway, moves through the room and then is removed. For diseases where there is natural or vaccine-acquired immunity (e.g., chicken pox or measles), healthcare workers who are immune do not usually need any additional respiratory precautions to enter the AIIR. Non-immune workers should not enter the room; in an emergency, they could use the procedure for diseases where there is no immunity (see below). For tuberculosis or other diseases where there is no question of immunity, some form of personal respiratory protection is required. At a minimum, a respirator is recommended for anyone entering the room. It is imperative that patients who are even suspected of having TB, chicken pox or measles be placed on airborne precautions promptly. Although this will lead to a certain degree of isolation, that is far preferable to having other patients and healthcare workers infected because isolation seemed like too much trouble. Contact Precautions Contact precautions are used with patients infected or colonized with organisms that are spread primarily via the hands of healthcare workers, or via contact with contaminated surfaces (such as,hospital bedrails, blood-pressure cuffs). While many organisms can spread this way, contact precautions are reserved for organisms that are either:
Controlling the Spread of Drug-Resistant Organisms Multi-drug resistant organisms (MDROs) have become an increasing problem in American hospitals. MDROs include MRSA, VRE, C. diff and multi-drug resistant gram-negative rods (MDR-GNR). Reports from the CDC indicate that in ICUs MRSA now makes up 60% of S. aureus cases.6 Likewise, resistance in other categories of disease-causing bacteria showed a steady increase.6,7 Unfortunately, few new antibiotics are in the production pipeline. Thus, as MDROs become increasingly resistant, there may be no effective means to treat patients infected with them. Already hospitals are seeing increasing numbers of infections with Acinetobacter that are resistant to all available antibiotics. This makes it all the more important that infections with these organisms be prevented in the first place. The mainstay of preventing the spread of MDROs is the effective use of contact precautions. Unfortunately, MDROs are becoming more and more common. This may be caused in part by poor adherence to contact precautions, standard precautions and hand hygiene on the part of healthcare workers. Nevertheless, traditional efforts have not proven to be entirely effective, especially with so-called "colonized" patients who have no symptoms but who can act as "reservoirs" that spread infection unpredicably to other patients.8,9 Modern, molecular-based testing allows for rapid identification of colonized patients.10 Some states, such as Illinois, have mandated active surveillance for MRSA in hospitals.11,12 Device-Associated Infections While any medical device that enters the body can carry an increased risk of infection, the device-associated infections that are most common -- and that receive the most attention -- are catheter-associated bloodstream infections (CABSI), ventilator-associated pneumonia (VAP) and catheter-associated urinary tract infections (CAUTI). The surest way to prevent a device-associated infection is not to use the device. The need for these devices should be evaluated daily and they should be discontinued as soon as they are no longer necessary. Catheter-Associated Bloodstream Infections Over 250,000 CABSIs are estimated to occur each year in U.S. hospitals, prolonged hospitalization before catheterization, prolonged duration of catheterization, internal jugular catheterization, femoral catheterization (in adults) and substandard catheter care (e.g., many line breaks; low nurse-to-patient ratio) are factors that increase a patient's risk of CABSI. A number of measures have been proven to reduce the risk of CABSI -- these are listed in Table 1. The use of maximal sterile barrier precautions during catheter placement means that the inserter should have a sterile gown and gloves on, as well as a surgical mask and hair-cover. Any assistant working nearby should be similarly attired. The patient should be covered with a broad sterile drape that covers most, if not all, of the body. Comprehensive programs to prevent CABSI, including extensive education of healthcare workers, have led to CABSI rates as low as 0 in many ICUs.13,14 Table 2. Ways to Reduce the Risk of CABSI.
Ventilator-Associated Pneumonia Ventilator-associated pneumonia (VAP) is primarily a problem of intensive care units. Rates in the U.S. range from 2.5-12.3 episodes of VAP per 1000 ventilator days. The death rate is about 10%. Table 3 lists recommendations for reducing the risk of VAP.15 The top 10% of all U.S. ICUs reporting to NHSN have a VAP rate of 0 and for some ICU types the top 25% have a rate of 0. These results demonstrate what can be achieved with heightened efforts. Table 3. Ways to Reduce the Risk of VAP.
Urinary Tract Infections Catheter associated urinary tract infections (CAUTI) are the most common device-associated infection. Although UTIs are often not seen as "serious" infections, they do cause increases in hospital length of stay and cost. Table 4 lists measures that can reduce the risk of a CAUTI. While proper catheter insertion and care techniques can reduce the risk, the likelihood of eventually developing a CAUTI is a near certainty if the urinary catheter is left in long enough. The primary focus in CAUTI reduction is to ensure that urinary catheters are discontinued as soon as they are no longer medically necessary.16 Surgical Site Infections Surgical site infection rates vary tremendously, depending on the surgical procedure involved. A number of measures, however, have been clearly demonstrated to lower surgical site infection rates.17
There is increasing evidence that healthcare-associated infections are largely preventable. Increased public awareness and legislative efforts have helped spur healthcare institutions to implement better infection-control procedures. It is very likely that soon, all healthcare workers will have at least some knowledge of the basics regarding the detection and prevention of healthcare associated infections, and, more importantly, take steps to implement sound infection prevention measures. Additional Resources Lautenbach E, Woeltje K, editors. SHEA Practical Handbook for Healthcare Epidemiologists, 2nd Edition. Thorofare, NJ: SLACK, Inc.; 2004. Society for Healthcare Epidemiology of America (SHEA) http://www.shea-online.org Association of Professionals in Infection Control and Epidemiology http://www.apic.org CDC Division of Healthcare Quality Promotion (DHQP) http://www.cdc.gov/ncidod/dhqp/index.html
References 1. Klevens RM, Edwards JR, Richards CL Jr, Horan TC, Gaynes RP, Pollock DA, Cardo DM. Estimating health care-associated infections and deaths in U.S. hospitals, 2002. Public Health Rep. 2007;122:160-166. return 2. Edwards JR, Peterson KD, Andrus ML, Tolson JS, Goulding JS, Dudeck MA, Mincey RB, Pollock DA, Horan TC; NHSN Facilities. National Healthcare Safety Network (NHSN) Report, data summary for 2006, issued June 2007. Am J Infect Control. 2007;35:290-301. return 3. Centers for Disease Control and Prevention. Guideline for Hand Hygiene in Health-care Settings. MMWR 2002;51(No. RR-16). return 4. Siegel JD, Rhinehart E, Jackson M, Chiarello L, and the Healthcare Infection Control Practices Advisory Committee. Guideline for Isolation Precautions: Preventing Transmission of Infectious Agents in Healthcare Settings, 2007. http://www.cdc.gov/ncidod/dhqp/pdf/isolation2007.pdf. Last accessed 12/31/2007. return 5. Puzniak LA, Leet T, Mayfield J, Kollef M, Mundy LM. To gown or not to gown: the effect on acquisition of vancomycin-resistant enterococci. Clin Infect Dis 2002;35:18-25. return 6. NNIS System. National Nosocomial Infections Surveillance (NNIS) System Report, data summary from January 1992 through June 2003, issued August 2003. Am J Infect Control 2003;31;481-498. return 7. Siegel JD, Rhinehart E, Jackson M, Chiarello L, and the Healthcare Infection Control Practices Advisory Committee. Management of Multidrug-Resistant Organisms In Healthcare Settings, 2006. http://www.cdc.gov/ncidod/dhqp/pdf/ar/MDROGuideline2006.pdf Last accessed 12/31/2007. return 8. Muto CA, Jernigan JA, Ostrowsky BE, Richet HM, Jarvis WR, Boyce JM, Farr BM; SHEA. SHEA guideline for preventing nosocomial transmission of multidrug-resistant strains of Staphylococcus aureus and enterococcus. Infect Control Hosp Epidemiol. 2003;24:362-386. return 9. Woeltje KF, Kollef MH, Osamudiamen OE, Fraser VJ, Warren DK. Epidemiology of Methicillin-Resistant and -Sensitive Staphylococcus aureus in a Medical Intensive Care Unit. Infectious Diseases Society of America 44rd Annual Meeting. Toronto, ON. October 2006. return 10. Struelens MJ, Denis O. Rapid molecular detection of methicillin-resistant Staphylococcus aureus: a cost-effective tool for infection control in critical care? Crit Care. 2006;10:128. return 11. Boyce JM. MRSA patients: proven methods to treat colonization and infection. J Hosp Infect. 2001;48 Suppl A:S9-14. return 12. Gorwitz RJ, Jernigan DB, Powers JH, Jernigan JA, and Participants in the CDC-Convened Experts' Meeting on Management of MRSA in the Community. Strategies for clinical management of MRSA in the community: Summary of an experts' meeting convened by the Centers for Disease Control and Prevention. 2006. Available at http://www.cdc.gov/ncidod/dhqp/ar_mrsa_ca.html. Last accessed 12/31/07. return 13. Centers for Disease Control and Prevention. Guidelines for the Prevention of Intravascular Catheter-Related Infections. MMWR 2002;51(No.RR-10). return 14. Warren DK, Cosgrove SE, Diekema DJ, Zuccotti G, Climo MW, Bolon MK, Tokars JI, Noskin GA, Wong ES, Sepkowitz KA, Herwaldt LA, Perl TM, Solomon SL, Fraser VJ; Prevention Epicenter Program. A multicenter intervention to prevent catheter-associated bloodstream infections. Infect Control Hosp Epidemiol. 2006;27:662-669. return 15. Centers for Disease Control and Prevention. Guidelines for preventing health-care-associated pneumonia, 2003: recommendations of CDC and the Healthcare Infection Control Practices Advisory Committee. MMWR 2004;53(No. RR-3). return 16. Wong ES. Guideline for Prevention of Catheter-associated Urinary Tract Infections. 1981. Available at http://www.cdc.gov/ncidod/dhqp/gl_catheter_assoc.html. Last accessed 1/2/08. return 17. Mangram AJ, Horan TC, Pearson ML, Silver LC, Jarvis WR. Guideline for prevention of surgical site infection, 1999. Hospital Infection Control Practices Advisory Committee. Infect Control Hosp Epidemiol. 1999;20:250-278. return 18. Bratzler DW, Houck PM. Antimicrobial prophylaxis for surgery: an advisory statement from the National Surgical Infection Prevention Project. Clin Infect Dis. 2004;38:1706-1715. return |
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Sepsis, a severe infection, usually causes fever but elderly victims can have no fever or even subnormal
temperatures. 