Nosocomial infection

Nosocomial infections are infections which are a result of treatment in a hospital or a healthcare service unit, but secondary to the patient's original condition (and as such are a category of iatrogenic artefacts). Infections are considered nosocomial if they first appear 48 hours or more after hospital admission or within 30 days after discharge. Nosocomial comes from the Greek word nosokomeion (νοσοκομείον) meaning hospital (nosos = disease, komeo = to take care of). This type of infection is also known as a hospital-acquired infection (or more generically healthcare-associated infections).

Nosocomial infections are even more alarming in the 21st century. The main reason are the followings:

Thorough hand washing and/or use of alcohol rubs by all medical personnel before each patient contact is one of the most effective ways to combat nosocomial infections¹. More careful use of anti-microbial agents, such as antibiotics, is also considered vital.[2]

Epidemiology

In the United States, it has been estimated that as many as one hospital patient in ten acquires a nosocomial infection, or 2 million patients a year. Estimates of the annual cost range from $4.5 billion to $11 billion and up. Nosocomial infections contributed to 88,000 deaths in the U.S. in 1995. One third of nosocomial infections are considered preventable. Ms. magazine reports that as many as 92 percent of deaths from hospital infections could be prevented. ² The most common nosocomial infections are of the urinary tract, surgical site and various pneumonias ³

In France, prevalence was 6.87% in 2001⁴ and 7.5% in 2006⁵ (some patients were infected twice) :

An estimated 5% to 19% of hospitalized patients are infected, and up to 30% in intensive care units. The patients must stay in the hospital 4-5 additional days. About 9,000 people die with a nosocomial infection, but about 4,200 would have survived without this infection.

In Italy, in the 2000s, about 6.7 % of hospitalized patients were infected, i.e. between 450,000 and 700,000 patients, which caused between 4,500 and 7,000 deaths.⁶

In Switzerland, extrapolations assume about 70,000 hospitalised patients are affected by nosocomial infections (between 2 and 14% of hospitalized patients).⁷

Transmission

Microorganisms are transmitted in hospitals by several routes, and the same microorganism may be transmitted by more than one route. There are five main routes of transmission -- contact, droplet, airborne, common vehicle, and vectorborne.

Predisposition to infection

Factors predisposing a patient to infection can broadly be divided into four areas:

Prevention

Isolation

Isolation precautions are designed to prevent transmission of microorganisms by common routes in hospitals. Because agent and host factors are more difficult to control, interruption of transfer of microorganisms is directed primarily at transmission.

Handwashing and gloving

Handwashing frequently is called the single most important measure to reduce the risks of transmitting microorganisms from one person to another or from one site to another on the same patient. Washing hands as promptly and thoroughly as possible between patient contacts and after contact with blood, body fluids, secretions, excretions, and equipment or articles contaminated by them is an important component of infection control and isolation precautions.

Although handwashing may seem like a simple process, it is often performed incorrectly. Healthcare settings must continually remind practitioners and visitors on the proper procedure in washing their hands to comply with responsible handwashing. Simple programs such as Henry the Hand, and the use of handwashing signals can assist healthcare facilities in the prevention of nosocomial infections.

All visitors must follow the same procedures as hospital staff to adequately controlled the spread of infections. Visitors and healthcare personnel are equally to blame in transmitting infections. Moreover, multi-drug resistant infections can leave the hospital and become part of the community flora if we don't take steps to stop this transmission.

In addition to handwashing, gloves play an important role in reducing the risks of transmission of microorganisms. Gloves are worn for three important reasons in hospitals. First, gloves are worn to provide a protective barrier and to prevent gross contamination of the hands when touching blood, body fluids, secretions, excretions, mucous membranes, and nonintact skin; the wearing of gloves in specified circumstances to reduce the risk of exposures to bloodborne pathogens is mandated by the OSHA Bloodborne Pathogens final rule. Second, gloves are worn to reduce the likelihood that microorganisms present on the hands of personnel will be transmitted to patients during invasive or other patient-care procedures that involve touching a patient's mucous membranes and nonintact skin. Third, gloves are worn to reduce the likelihood that hands of personnel contaminated with microorganisms from a patient or a fomite can transmit these microorganisms to another patient. In this situation, gloves must be changed between patient contacts and hands should be washed after gloves are removed.

Wearing gloves does not replace the need for handwashing, because gloves may have small, non-apparent defects or may be torn during use, and hands can become contaminated during removal of gloves. Failure to change gloves between patient contacts is an infection control hazard.

Aprons

Wearing an apron during patient care reduces the risk of infection.^{citation needed} The apron should either be disposable or be used only when caring for a specific patient.

Mitigation

The most effective of controlling nosocomial infection is to strategically implementing QA / QC measures to the health care sectors and evidence-based management can be a feasible approach. For those VAP/HAP diseases (ventilator-associated pneumonia, hospital-acquired pneumonia), controlling and monitoring hospital indoor air quality needs to be on agenda in management ⁹ whereas for nosocomial rotavirus infection, a hand hygiene protocol has to be enforced.¹⁰¹¹¹²

Known diseases

References

^ McBryde, E.S.; L.C. Bradley, M. Whitby, D.L. McElwain (2004). "An investigation of contact transmission of methicillin-resistant Staphylococcus aureus". Journal of Hospital Infection 58 (2): 104-108. PMID 15474180.
^ Ricks, Delthia. "Germ Warfare." Ms. Magazine. Spring 2007. pp 43-45.[1]
^ Kelvens, R.M.; et al. (2007). "Estimating health care-associated infections and deaths in U.S. hospitals, 2002". Public Health Reports 122 (2): 160-166. PMID 17357358.
^ enquête nationale de prévalence 2001
^ Quelle est la prévalence de ces infections ?
^ L'Italie scandalisée par "l'hôpital de l'horreur", Éric Jozsef, Libération, January 17, 2007 (French)
^ Facts sheet - Swiss Hand Hygiene Campaign. (.doc)
^ Jain, S.K.; et al. (July 2005). "Nosocomial malaria and saline flush". Emerging Infectious Diseases 11 (7): 1097-1099. PMID 16022788, http://www.cdc.gov/ncidod/EID/vol11no07/05-0092.htm.
^ Leung, M.; A.H.S. Chan (2006). "Control and management of hospital indoor air quality". Med Sci Monit 12 (3): SR17-23. PMID 16501436.
^ Chan, P.-C.; et al. (2007). "Control of an Outbreak of Pandrug-Resistant Acinetobacter baumannii Colonization and Infection in a Neonatal Intensive Care Unit". Infect Control Hosp Epidemiol 28 (4): 423-429. PMID 17385148.
^ Josie, L. et al. (2006). Pilot study to evaluate 3 hygiene protocols on the reduction of bacterial load on the hands of veterinary staff performing routine equine physical examinations. PMID 16898109.
^ Katz, J.D. (2004). "Hand washing and hand disinfection: more than your mother taught you". Anesthesiol Clin North America 22 (3): 457-471, vi. PMID 15325713.

Contents