General informations
- 17/3/2022 – France: the National Plan on Infection Control and Antibiotic Resistance
- 2/24/2022 – Section updated
Infections associated with hospitalization were originally defined as “nosocomial infections”, but since the 1990s, with the expansion of out-of-hospital care facilities, there has been a need to expand the concept to health and social care .
Healthcare-Related Infections (HAIs) are defined as infections due to bacteria, fungi, viruses or other less common pathogens, contracted during healthcare, which can occur in any healthcare setting (hospitals, surgeries, centers of dialysis, long-term care, home assistance, territorial residential structures) and which at the time of entry into the structure or before the provision of assistance were not clinically manifest, nor were they incubating.
In the latest prevalence study conducted in acute care hospitals (all hospitals that assist patients for short periods) in Italy (2016), 1296 HAIs were observed in 1186 patients. Of these, the most commonly encountered infections were: respiratory (22.8%), bacteremia (18.3%), urinary (18%) and surgical site (14.4%).
As regards the microorganisms involved, out of 67 types of pathogens identified, Escherichia coli (13%), Klebsiella pneumoniae (10.4%), Pseudomonas aeruginosa (8.1%), Staphylococcus aureus (8.9%) and Staphylococcus epidermidis (6.3%) account for more than 45% of all isolations, often identified as multi-resistant.
In recent years, a strong focus has been placed on the prevention and control of these infections due to a constantly growing epidemiological trend with strong repercussions on the health of the patients, as well as on the psychological and financial aspects which translate into: prolongation of the length of hospitalization , long-term disability, increased mortality, spread of antibiotic resistance, etc.
The expansion of HAIs is influenced by various factors, including for example the spread of microorganisms resistant to antibiotics and the progressive introduction of new health technologies, which, on the one hand, guarantee the survival of patients in serious conditions, on the other allow the entry of microorganisms even in normally sterile body sites.
A literature review conducted on 2005-2016 data found that approximately 35-55% of HAIs are preventable through multidisciplinary interventions.
Method of transmission
Transmission of infection during healthcare requires three elements: the source of infecting microorganisms, a susceptible host and a means of transmission from the microorganism to the host.
Infection can be endogenous when the source is represented by pathogens present within the body, but more frequently exogenous. In this case, the infection is transmitted from the outside through medical equipment or devices, the environment, healthcare personnel, contaminated drugs.
Like other infections, the transmission of HAIs also depends on the microorganism involved, and can occur in several ways:
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direct contact between a healthy and an infected person, especially through the hands of the operators - via droplet, contact via droplets emitted with coughing and sneezing by an infected person
- by air, through small microorganisms that remain suspended in the air for long periods of time
- indirect contact through a contaminated vehicle (e.g. endoscopes or surgical instruments)
- transmission of the infection to several people through a common contaminated vehicle (food, infusion liquids, etc.).
Risk factors
The subjects at risk of contracting an ICA are mainly patients and, less frequently, the staff involved in assistance. The factors that make these subjects, but especially patients, at risk of contracting a HAI may be extrinsic, intrinsic or related to predisposing care practices.
Extrinsic risk factors:
- length of stay (taking into account the fact that the true incidence of HAIs may be underestimated as the hospital stay may be shorter than the incubation period of the infecting organism and symptoms may also occur days after the patient is discharged)
- use of invasive devices (CVP, CVC, bladder catheter, intubation);
- admission to intensive care
- surgical interventions.