Nosocomial infections known also as hospital-acquired infections, hospital-associated infections, and hospital infections are infections that are not present in the patient at the time of admission to hospital but develop during the stay in hospital. The term “health care-associated infection” or “HAI” is now used in place of the older term “hospital infection”, because such infections do not develop solely in hospitals, but can also arise in a long-term care facility or in a doctor’s surgery.
Good hospital hygiene is vital to any strategy for preventing HAIs (healthcare associated infection) in hospitals. There is evidence upon which recommendations for hospital environmental hygiene are based, with the relevant standards. Guidelines are provided e.g. for cleaning the general hospital environment, cleaning items of shared equipment and education and training of staff. There exists clinical evidence obtained from case reports and outbreak investigations suggesting dependence between poor environmental hygiene and the transmission of microorganisms causing HAIs in hospital.
Transmission of microorganisms from the environment to patients may occur through direct contact with contaminated equipment, or indirectly as a result of touching by hands. Methicillin-resistant Staphylococcus aureus (MRSA) and other pathogens have been recovered from a range of surfaces commonly touched, such as door handles, computer keyboards, soap dispensers, and sink taps, and sites where dust is allowed to accumulate.
Two different forms of infections can be distinguished. Endogenous infection, self-infection, or auto-infection. The causative agent of the infection is present in the patient at the time of admission to hospital but there are no signs of infection. The infection develops during the stay in hospital as a result of the patient’s altered resistance. The second form is cross-contamination followed by cross-infection. During the stay in hospital the patient comes into contact with new infective agents, becomes contaminated, and subsequently develops an infection. While there is no clinically significant difference between the endogenous self-infection and the exogenous cross-infection, the distinction is important from the standpoint of epidemiology and prevention.
For example in U.S., there are quality standards for hospital cleanliness developed by the Infection Control Nurses Association and the Association of Domestic Managers (NHS Estates, 2000), NHS Healthcare Cleaning Manual (NHS Estates, 2004), and regulations (NHSE, 1995; 1989), and clinical governance guidance (NHSE, 1998), all providing a framework within which hospital environmental hygiene can be improved and monitored. The NHS Code of Practice on the Prevention and Control of Healthcare Associated infection, which came into effect in October 2006, was developed to help organizations to plan and implement strategies for the prevention and control of HAIs.
Many microorganisms recovered from the hospital environment do not cause HAI. Cleaning will not completely eliminate microorganisms from environmental surfaces and reductions in their numbers will be transient. There is evidence that improved cleaning regimens are associated with the control of outbreaks of HAIs. In one study (Rampling 2001), the control of an outbreak of an epidemic strain of MRSA was linked with increased cleaning hours and an emphasis on the removal of dust.
Indicators of cleanliness based on levels of microbial or adenosine triphosphate (ATP) contamination have been proposed but are based on arbitrary standards of acceptable contamination and do not distinguish between normal environmental flora and pathogens responsible for HAI.
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