The current science around acquisition and prevention of nosocomial infections
Nosocomial infections are prevalent in our social structure. Health care is essential for leading normal life and these facilities are provided in hospitals, nursing homes, where there are great chances for the acquisition of infections. These infections can cause morbidity and mortality. Public health problem in today’s life is a major concern with growing economy because of out burst of population. People usually have weak immune system and they are less resistant to deadly infection (Ducel, 1995). Nosocomial infections are likely to be acquired by someone after he release from the hospital, if the patient was in the incubation period at the time of discharge. It has been suggested that hand disinfection is a important step in reducing nosocomial infections. The purpose of the present paper is to delineate current acquisition and risk factor involved in nosocomial infections. There is a need for risk assessment associated with main types of infection and must know the method by which these infections can be prevented. The Study on the effectiveness of Nosocomial Infection Control (SENIC) project provided the influential technical basis to assertion that close watch is an crucial element of an infection control program and progresses the outcomes of patients (Haley , 1985).
From centuries, populace have documented the nosocomial infections as a dangerous dilemma which affect the health care system and it is a prime source of undesirable healthcare outcomes (Gaynes, 1999). Nosocomial infections are responsible for causing many preventable disease and casualty in developing countries. The National Nosocomial Infections Surveillance (NNIS) defines a “nosocomial infection as a localized or systemic condition that results from adverse reaction to the presence of an infectious agents or its toxins and that was not present or incubating at the time of admission to the hospital” (Garner , 1996). When infection is acquired in health care setting, they can lead to death and increased morbidity among hospitalized patients. These infections put heavy load on the patient and public health. Nosocomial infection is developed by a series of events, which is influenced by the microbes, transmission route, and the patient himself (Gaynes, 1999). There are nearly 100 million procedures executed at hospitals each year, litigation arising from nosocomial infections is escalating on a national scale. It is well understood that these infections can be acquired in the hospital, nursing home, rehabilitation centers, as well as extended care facilities. The organisms which cause most nosocomial infections generally come from the patient’s own body (Garner, 1996). These infections can also spread from with staff, contaminated instruments and needles, and the environment (Garner, 1996). Immuno compromised patients, the elderly and young children are usually more at risk than others. The Centers for Disease Control of the U.S. Department of Health and Human Services explains for surveillance of nosocomial infections. According to the CDC, the most widespread pathogens that are the source nosocomial infections are Staphylococcus aureus, Pseudomonas aeruginosa, and E. coli. Nosocomial infections do not only acquired through bacteria but certain fungi such as Candida albicans and aspergillus, and viruses such as Respiratory Syncytial Virus and influenza have also been a matter of concern for hospital acquired infections. An occurrence survey conducted under the auspices of WHO in 55 hospitals of 14 countries representing four WHO Regions namely Europe, Eastern Mediterranean, South-East Asia and Western Pacific, demonstrated an average of 8.7% of hospital patients had nosocomial infections. It can be estimated that over 1.4 million people worldwide undergo from infectious complications acquired in hospitals (Tikhomirov E, 1987). Reports indicate that highest number of patient with nosocomial infections were reported from hospitals in the Eastern Mediterranean and South-East Asia Regions (11.8 and 10.0% respectively), with a prevalence of 7.7 and 9.0% respectively in the European and Western Pacific Regions (Mayon , 1988). Hospital-acquired infections have dangerous consequences. These infections lead to functional disability and emotional trauma of the patient and in some cases, lead to immobilizing conditions that make living condition very difficult. Nosocomial infections alone can worsen human life (Ponce-de-Leon S, 1991). There are 5% to 10% of patients admitted to acute care hospitals in developed countries (Ayliffe, 2000). The attach rate for developing countries are more affected due to less awareness about these infections and can exceed 25% in comparison to developed countries (Young,1995).
Most nosocomial infections are predictable risks related to cure. Due to the development of modern techniques in the treatments of critical diseases, there are number of patients whose resistance to infection is considerably low Gaynes, 1999), moreover, modern treatments need the use of intravenous catheters, urinary catheters, respirators, hemodialysis, complicated operations, cortisone therapy and other factors, which makes to patients more vulnerable to infections (Weinstein, 1998). Most nosocomial infections are not related to epidemic but occur consistently as sporadic cases (Daschner, 2002). It is observed that observation for nosocomial infections is the keystone of prevention and control (Arya, 2004).
Acquisition of nosocomial infection is determined by patient factors, such as the extent of immunocompromise, and interventions carried out making an increase in risk of catching infection (Underwood MA, 1998). The intensity of patient care practice may vary for patient groups at diverse risk of acquisition of infection. It has been well demonstrated that transmission of these infections are mainly due to hands (Larson E, 1988), and it can be lessened if proper hand hygiene is maintained (Larson EL, 1995). Generally in hospital, staff do not follow the appropriate and recommended medical procedure while dealing with patient. This may be due to various reasons such as lack of suitable accessible equipment, high staff-to-patient ratios, allergic reaction to hand washing products, inadequate knowledge of staff about risks and measures, too long a duration recommended for washing, and the time required. A number of nosocomial opportunistic fungal infections which are acquired in hospital setting which include phaeohyphomycosis, which is caused by dematiaceous fungi. These are omnipresent fungi found in plant pathogens and soil. It can be analyzed that there are certain high risk areas such as the intensive care renal dialysis and organ transplant units, burns ward, cancer ward, operation theatres, post-operation theatres, post operative ward nursery and the geriatric ward where nosocomial infections are most widespread (Krishna, 2000).
The chances of acquiring nosocomial infections depends on certain patient factors such as age, immune status, underlying disease, and diagnostic and therapeutic interventions. The extremes of life infancy and old age are linked with a reduced resistance to infection. Patients who are suffering from chronic diseases such as malignant tumours, leukaemia, diabetes mellitus, renal failure, or the acquired immunodeficiency syndrome (AIDS) may add to the vulnerability to infections with opportunistic pathogens. Basically in health care settings, both infected persons and other persons are at augmented risk of infection. When a patient who already is infected or carriers of pathogenic microorganisms, admitted to hospital, he/she has potential to transmit the nosocomial infections to other persons such as attendants and medical staff. Patients when caught infection in the hospital is additional source of infection. In health care setting, crowded conditions within the hospital, frequent transfers of patients from one unit to another, and attentiveness of patients can transmit infection. Burn patients, intensive care units are highly susceptible area where staff can acquire nosocomial infections (WHO, 2002).
The most general types of nosocomial infections that are transmitted in health care surgical wound and other soft tissue infections consisting of Urinary tract infections, Respiratory infections, Gastroenteritis, Meningitis, surgical site wound infections, bacteremia, gastrointestinal and skin infections. In a predominance survey (Emmerson et al 1996), it was found that there is high occurrence of surgical wound infection of all hospital-acquired infections. In the USA incidence study, surgical wound infection responsible for 24% of all nosocomial infections. These infections are spread in hospital mainly by two methods that are Aerial and Contact. Infection through Aerial transmission can be spread from the nose or mouth of the person or from inorganic sources like the air-conditioning plants, respiratory apparatus etc. a variety of infections including measles, small pox, tuberculosis, sepsis by Staphylococcus aureus and Streptococcus pyogenes, meningococcal infections, respiratory diseases related with Streptococcus pneumoniae, Streptococcus pyogenes. From inanimate sources aerial increase could result in respiratory infections by Enterobacteria, Pseudomonas aeruginosa and Legionella. It can also be transmitted by contact that could be either from other patients, doctors, nurses and other staff or from independent environmental sources. Any of these contacts may transmit respiratory infection, sepsis or diarrhea. If the medical staff directly comes in contact to tissue or wounds or mucous membranes by infected needles, surgical instruments or by blood or blood products, it may lead to dangerous consequences such as serious infections like hepatitis or AIDS (Krishna, 2000).
There are other solid bases for the acquisition of these infections. Some patients are exceedingly movable and their stay in hospital is for very short duration. They are discharged before the infection becomes evident. As a result, it is very difficult for a doctor to find about the source of the infection. Current studies indicate that nosocomial pneumonia was the most frequent infection. In United States, it was reported in the second rank (American Thoracic Society, 1996). In recent times, it has been stated that nosocomial urinary tract infection (NUTI) was the widespread infection in hospital care setting. More and more patients are coming with such infections. In intensive care units nosocomial infections are at the peak. In other units where most severely ill patients are treated, the maximum mortality rates are observed (Richards, 1999). Statistical data acquired after a close watch of endemic rates of nosocomial infections shows that more than 90% of nosocomial infections do not arise in recognized epidemics (Stamm, 1981).
Nosocomial infections usually occur in health care setup so the preventive measures should be concentrated around hospitals and other health care facilities (Schechler, 1998). It is the liability of health authorities to expand a national program to maintain hospitals in curbing the danger of nosocomial infections. Prevention efforts must be tight to avoid risk for acquisition of infection in patients and staff in the hospital facilities. Health care organizations must employ specialists, infection control physicians and infection control practitioners (usually nurses) to control the infection in effectual way (Schechler, 1998). The major task of specialist who are in charge of controlling the program, is to develop an yearly work plan to evaluate and endorse good health care, proper isolation, sterilization, and other practices, staff training, and epidemiological observation. Hospitals must be well equipped to afford enough resources to maintain this program. Another important tool is the nosocomial infection prevention manual (Savey, 2001), which is compiled with recommended instructions and practices for patient care. From time to time these manuals must be updated by the infection control team, with review and consent by the committee (WHO, 2002). The main task of an Infection Control Committee which provides a forum for multidisciplinary input and cooperation, and information giving out is to evaluate and support a yearly program of activity for inspection and prevention, to analysis epidemiological surveillance data and categorize areas for intervention to assess and prop up improved practice at all levels of the health facility to make certain suitable staff training in infection control and wellbeing. Prevention of nosocomial infections is not the liability of administration or specialist alone but everyone must hold the responsibility in providing health care (WHO, 2002). The CDC (1985) on the effectiveness of nosocomial infection control (SENIC) illustrated that directly observing activities in hospitals slows down the rates of nosocomial infections. All methods aimed at to control the infection must principally be focused on these high risk areas. In developing countries, an infection control program is hindered due to restricted resources in hospitals, improper sterilization and disinfection procedures, poor quality of water and food offered in the hospital, the hospital surroundings itself, untrained staff, the lack of knowledge of hospital infection control principles and practices among the staff and the general mishandling of medicines both in the public and in the hospital (Krishna, 2000).
Physicians must have part of their duty to prevent and control hospital infections. They can promote patient care using practices which may reduce infection by following proper practice of hygiene such as hand washing, isolation etc. (WHO, 2002). The role of microbiologist is also important in preventing to the spread of these infections. They are liable for managing patient and staff specimens to maximize the probability of a microbiological diagnosis and setting guidelines for proper collection, transport, and handling of specimens, making sure laboratory practices meet appropriate values, ensuring protected laboratory practice to avoid infections in staff who are supporting the infection control team (WHO, 2002). Prevention of nosocomial infections is also a part of proper personal hygiene and hand washing of the hospital staff, complete sterilization of medical equipment, and providing a hygienic, sanitary atmosphere in the health care facilities. There are certain diseases such as Diabetes, Immune suppression, Irradiation, Malnutrition, Steroid therapy which may be a cause of these infections. While handling these patients, extensive care should be taken by appointed paramedical staff when engaged in preoperative preparation, shaving of hair from the site because clipping of the hair has been related with a much higher frequency of infection. It is tested that staphylococcus aureus is the leading species in surgical wound infection, which is followed by the enterobacteria. Although S. aureus is common in all types of wound, it is the usual cause of wound infection in clean surgery. Normally surgical wound infection spread at the time of surgery. It is highly recommended for all staff to maintain high-quality personal hygiene. Common tips such as nails must be clean and kept short, false nails should not be worn, hair must be pinned up. Beard and moustaches must be kept trimmed short and clean. Staff can usually wear a personal uniform or street clothes covered by a white coat (WHO, 2002).
To sum up, nosocomial infections are more common in among hospitalized patients. Even in the revolutionary changes in the field of medical science in modern era of antibiotics, nosocomial infections keep on to remain a significant and dreadful outcome of hospitalization. Scientific reports estimated that about 23.5% of patients acquire these infections at the time of discharge. It depends on the case, hospital size and manifolds other factors. For postoperative ICU patients, the nosocomial infections are the foremost cause of septic complications and its appearance in ICU further increases. In any health care unit, the rate of the nosocomial in patients represents a quality and safety of care in a facility. It is very important to conduct surveillance process to keep an eye on this rate by which experts can identify local problems and priorities, and assess the efficacy of infection control activity. Hospital-acquired infections can be decreased by surveillance which is the only effective process to prevent the frequency of deadly infection (Gaynes , 1998).
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