Infection Control

Infection Control 

Definition

Infection control refers to policies and procedures used to minimize the risk of spreading infections, especially in hospitals and human or animal health care facilities.

Purpose

The purpose of infection control is to reduce the occurrence of infectious diseases. These diseases are usually caused by bacteria or viruses and can be spread by human to human contact, animal to human contact, human contact with an infected surface, airborne transmission through tiny droplets of infectious agents suspended in the air, and, finally, by such common vehicles as food or water. Diseases that are spread from animals to humans are known as zoonoses; animals that carry disease agents from one host to another are known as vectors.

Infection control in hospitals and other health care settings

Infections contracted in hospitals are also called nosocomial infections. They occur in approximately 5% of all hospital patients. These infections result in increased time spent in the hospital and, in some cases, death. There are many reasons nosocomial infections are common, one of which is that many hospital patients have a weakened immune system which makes them more susceptible to infections. This weakened immune system can be caused either by the patient's diseases or by treatments given to the patient. Second, many medical procedures can increase the risk of infection by introducing infectious agents into the patient. Thirdly, many patients are admitted to hospitals because of infectious disease. These infectious agents can then be transferred from patient to patient by hospital workers or visitors.

Infection control has become a formal discipline in the United States since the 1950s, due to the spread of staphylococcal infections in hospitals. Because there is both the risk of health care providers acquiring infections themselves, and of them passing infections on to patients, the Centers for Disease Control and Prevention (CDC) established guidelines for infection control procedures. In addition to hospitals, infection control is important in nursing homes, clinics, child care centers, and restaurants, as well as in the home.

To lower the risk of nosocomial infections, the CDC began a national program of hospital inspection in 1970 known as the National Nosocomial Infections Surveillance system, or NNIS. The CDC reported that over 300 hospitals participate in the NNIS system as of the early 2000s. Data collected from the participating hospitals show that infection control programs can siginificantly improve patient safety, lower infection rates, and lower patient mortality.

Dental health care settings are similar to hospitals in that both personnel and equipment can transmit infection if proper safeguards are not observed. The CDC issued new guidelines in 2003 for the proper maintenance and sterilization of dental equipment, hand hygiene for dentists and dental hygienists, dental radiology, medications, and oral surgery, environmental infection control, and standards for dental laboratories.

The newest addition to the infection control specialist's resources is molecular typing, which speeds up the identification of a disease agent. Rapid identification in turn allows for timely containment of a disease outbreak.

Threat of emerging infectious diseases

Due to constant changes in our lifestyles and environments, new diseases are constantly appearing that people are susceptible to, making protection from the threat of infectious disease urgent. Many new contagious diseases have been identified in the past 30 years, such as AIDS, Ebola, and hantavirus. Increased travel between continents makes the worldwide spread of disease a bigger concern than it once was. Additionally, many common infectious diseases have become resistant to known treatments.

The emergence of the severe acute respiratory syndrome (SARS) epidemic in Asia in February 2003 was a classic instance of an emerging disease that spread rapidly because of the increased frequency of international and intercontinental travel. In addition, the SARS outbreak demonstrated the vulnerability of hospitals and health care workers to emerging diseases. Clusters of cases within hospitals occurred in the early weeks of the epidemic when the disease had not yet been recognized and the first SARS patients were admitted without isolation precautions.

The SARS epidemic also raised a number of ethical and legal questions regarding current attitudes toward infection control.

Problems of antibiotic resistance

Because of the overuse of antibiotics, many bacteria have developed a resistance to common antibiotics. This means that newer antibiotics must continually be developed in order to treat an infection. However, further resistance seems to come about almost simultaneously. This indicates to many scientists that it might become more and more difficult to treat infectious diseases. The use of antibiotics outside of medicine also contributes to increased antibiotic resistance. One example of this is the use of antibiotics in animal husbandry. These negative trends can only be reversed by establishing a more rational use of antibiotics through treatment guidelines.

Bioterrorism

The events of September 11, 2001, and the anthrax scare that followed in October 2001 alerted public health officials as well as the general public to the possible use of infectious disease agents as weapons of terrorism. The Centers for Disease Control and Prevention (CDC) now has a list of topics and resources related to bioterrorism on its web site.

Description

The goals of infection control programs are: immunizing against preventable diseases, defining precautions that can prevent exposure to infectious agents, and restricting the exposure of health care workers to an infectious agent. An infection control practitioner is a specially trained professional, oftentimes a nurse, who oversees infection control programs.

Commonly recommended precautions to avoid and control the spread of infections include:

Because of the higher risk of spreading infectious disease in a hospital setting, higher levels of precautions are taken there. Typically, health care workers wear gloves with all patients, since it is difficult to know whether a transmittable disease is present or not. Patients who have a known infectious disease are isolated to decrease the risk of transmitting the infectious agent to another person. Hospital workers who come in contact with infected patients must wear gloves and gowns to decrease the risk of carrying the infectious agent to other patients. All articles of equipment that are used in an isolation room are decontaminated before reuse. Patients who are immunocompromised may be put in protective isolation to decrease the risk of infectious agents being brought into their room. Any hospital worker with infections, including colds, are restricted from that room.

Hospital infections can also be transmitted through the air. Thus care must be taken when handling infected materials so as to decrease the numbers of infectious agents that become airborne. Special care should also taken with hospital ventilation systems to prevent recirculation of contaminated air.

Resources

Books

Beers, Mark H., MD, and Robert Berkow, MD, editors. "Immunizations for Adults." Section 13, Chapter 152. In The Merck Manual of Diagnosis and Therapy. Whitehouse Station, NJ: Merck Research Laboratories, 2004.

Periodicals

Ashford, D. A., R. M. Kaiser, M. E. Bales, et al. "Planning Against Biological Terrorism: Lessons from Outbreak Investigations." Emerging Infectious Diseases 9 (May 2003): 515-519.

Gostin, L. O., R. Bayer, and A. L. Fairchild. "Ethical and Legal Challenges Posed by Severe Acute Respiratory Syndrome: Implications for the Control of Severe Infectious Disease Threats." Journal of the American Medical Association 290 (December 24, 2003): 3229-3237.

Ho, P. L., X. P. Tang, and W. H. Seto. "SARS: Hospital Infection Control and Admission Strategies." Respirology 8, Supplement (November 2003): S41-S45.

Jacobson, R. M., K. S. Zabel, and G. A. Poland. "The Overall Safety Profile of Currently Available Vaccines Directed Against Infectious Diseases." Expert Opinion on Drug Safety 2 (May 2003): 215-223.

Jarvis, W. R. "Benchmarking for Prevention: the Centers for Disease Control and Prevention's National Nosocomial Infections Surveillance (NNIS) System Experience." Infection 31, Supplement 2 (December 2003): 44-48.

Kohn, W. G., A. S. Collins, J. L. Cleveland, et al. "Guidelines for Infection Control in Dental Health-Care Settings—2003." Morbidity and Mortality Weekly Reports: Reports and Recommendations 52, RR-17 (December 19, 2003): 1-61.

Peng, P. W., D. T. Wong, D. Bevan, and M. Gardam. "Infection Control and Anesthesia: Lessons Learned from the Toronto SARS Outbreak." Canadian Journal of Anaesthesiology 50 (December 2003): 989-997.

Petrak, R. M., D. J. Sexton, M. L. Butera, et al. "The Value of an Infectious Diseases Specialist." Clinical Infectious Diseases 36 (April 15, 2003): 1013-1017.

Sehulster, L., and R. Y. Chinn. "Guidelines for Environmental Infection Control in Health-Care Facilities. Recommendations of CDC and the Healthcare Infection Control Practices Advisory Committee (HICPAC)." Morbidity and Mortality Recommendations and Reports 52, RR-10 (June 6, 2003): 1-42.

Subramanian, D., J. A. Sandoe, V. Keer, and M. H. Wilcox. "Rapid Spread of Penicillin-Resistant Streptococcus pneumoniae Among High-Risk Hospital Inpatients and the Role of Molecular Typing in Outbreak Confirmation." Journal of Hospital Infection 54 (June 2003): 99-103.

Organizations

American College of Epidemiology. 1500 Sunday Drive, Suite 102, Raleigh, NC 27607. (919) 861-5573. http://www.acepidemiology.org.

American Public Health Association (APHA). 800 I Street NW, Washington, DC 20001-3710. (202) 777-APHA. http://www.apha.org.

American Veterinary Medical Association (AVMA). 1931 North Meacham Road, Suite 100, Schaumburg, IL 60173-4360. http://www.avma.org.

Centers for Disease Control and Prevention. 1600 Clifton Rd., NE, Atlanta, GA 30333. (800) 311-3435, (404) 639-3311. http://www.cdc.gov.

National Institute of Allergy and Infectious Diseases (NIAID). 31 Center Drive, Room 7A50 MSC 2520, Bethesda, MD, 20892. (301) 496-5717. http://www.niaid.nih.gov.