Infection Control and Health Care Epidemiology

Infection control and health care epidemiology is the discipline concerned with preventing the spread of infections within the health-care setting. As such, it is a practical (rather than an academic) sub-discipline of epidemiology. It is an essential (though often underrecognized and undersupported) part of the infrastructure of health care. Infection control and hospital epidemiology are akin to public health practice, practiced within the confines of a particular health-care delivery system rather than directed at society as a whole.

Infection control concerns itself both with prevention (hand hygiene/hand washing, cleaning/disinfection/sterilization, vaccination, surveillance) and with investigation and management of demonstrated or suspected spread of infection within a particular health-care setting (e.g. outbreak investigation). It is on this basis that the common title being adopted within health care is “Infection Prevention & Control”.

Hand hygiene

Independent studies by Ignaz Semmelweis in 1847 in Vienna and Oliver Wendell Holmes in 1843 in Boston established a link between the hands of health care workers and the spread of hospital-acquired disease. The Centers for Disease Control and Prevention (CDC) has stated that “It is well-documented that the most important measure for preventing the spread of pathogens is effective handwashing.” In the United States, hand washing is mandatory in most health care settings and required by many different state and local regulations as well as good sense.

In the United States, Occupational Safety and Health Administration (OSHA) standards require that employers must provide readily accessible hand washing facilities, and must ensure that employees wash hands and any other skin with soap and water or flush mucous membranes with water as soon as feasible after contact with blood or other potentially infectious materials (OPIM).

Cleaning, disinfection and sterilization…

Personal protective equipment

Personal protective equipment (PPE) is specialized clothing or equipment worn by a worker for protection against a hazard. The hazard in a health care setting is exposure to blood, saliva, or other bodily fluids or aerosols that may carry infectious materials such as Hepatitis C, HIV, or other blood borne or bodily fluid pathogen. PPE prevents contact with a potentially infectious material by creating a physical barrier between the potential infectious material and the healthcare worker. In the United States, the Occupational Safety and Health Administration (OSHA) requires the use of Personal protective equipment (PPE) by workers to guard against blood borne pathogens if there is a reasonably anticipated exposure to blood or other potentially infectious materials.

Components of Personal protective equipment (PPE) include gloves, gowns, bonnets, shoe covers, face shields, CPR masks, goggles, surgical masks, and respirators. How many components are used and how the components are used is often determined by regulations or the infection control protocol of the facility in question. Many or most of these items are disposable to avoid carrying infectious materials from one patient to another patient and to avoid difficult or costly disinfection. In the United States, OSHA requires the immediate removal and disinfection or disposal of worker’s PPE prior to leaving the work area where exposure to infectious material took place.

Vaccination of health care workers

Health care workers may be exposed to certain infections in the course of their work. Vaccines are available to provide some protection to workers in a healthcare setting. Depending on regulation, recommendation, the specific work function, or personal preference, healthcare workers or first responders may receive vaccinations for hepatitis B; influenza; measles, mumps and rubella; Tetanus, diphtheria, pertussis; N. meningitidis; and varicella. In general, vaccines do not guarantee complete protection from disease, and there is potential for adverse effects from receiving the vaccine.

Surveillance for emerging infections

Surveillance is the act of infection investigation using the CDC definitions. Determining an infection requires an ICP to review a patient’s chart and see if the patient had the signs and symptom of an infection. Surveillance definition cover infections of the bloodstream, Urinary tract, pneumonia, and sugical sites.

Surveillance traditionally involved significant manual data assessment and entry in order to assess preventative actions such as isolation of patients with an infectious disease. Increasingly, integrated computerised software solutions are becoming available, such as Infection Monitor Pro. Such products actively assess incoming risk messages from microbiology and other online sources. By reducing the need for data entry, this software significantly reduces the data workload of Infection Control Practitioners (ICP), freeing them to concentrate on clinical surveillance.

As approximately one third of healthcare acquired infections are preventable , surveillance and preventative activities are increasingly a priority for hospital staff. In the United States, a study on the Efficacy of Nosocomial Infection Control Project (SENIC) by the CDC found that hospitals reduced their nosocomial infection rates by approximately 32 per cent by focusing on surveillance activities and prevention efforts.

Outbreak investigation

When an unusual cluster of illness is noted, infection control teams undertake an investigation to determine whether there is a true outbreak, a pseudo-outbreak (a result of contamination within the diagnostic testing process), or just random fluctuation in the frequency of illness. If a true outbreak is discovered, infection control practitioners try to determine what permitted the outbreak to occur, and to rearrange the conditions to prevent ongoing propagation of the infection. Often, breaches in good practice are responsible, although sometimes other factors (such as construction) may be the source of the problem.