Nosocomial infection: definition, how to protect yourself?

According to figures published in May 2023 by Public Health FranceIn France, one in 18 hospitalized patients present at least one nosocomial infection i.e. 5.7% of patients. This prevalence of infected patients has increased by nearly 15% between 2017 and 2022, due to SARS-CoV-2 (COVID-19) infections transmitted in healthcare facilities. THE four main locations of nosocomial infections are: urinary infections, THE pneumonia, surgical site infections and bacteremia. And the four main microorganisms responsible for these infections are: Escherichia coli, Staphylococcus aureus, Enterococcus faecalisPseudomonas aeruginosa.

Definition: what is a nosocomial infection?

Nosocomial infections are infections contracted during a stay in a health establishment (hospital, clinic, etc.), and which were neither present nor incubating at the start of medical treatment. “This is not a medical definition, but a legal definition, explains Dr Jean Tafazzoli, general practitioner, almost all infectious diseases can be nosocomial if they were contracted in a health establishment. There are therefore as many symptoms, diagnoses and treatments as there are different nosocomial diseases”.

A portion of nosocomial infections can avoided by simple measures. As Dr. Tafazzoli explains, There are several messages to convey to limit these nosocomial infections :

• There is today too many emergency services : “You absolutely have to stop going to the emergency room for a sprain, a prescription renewal or gastroenteritis.” insists the doctor.
• It is also necessary limit visitors in the bedrooms:we sometimes see patients visited by 5 people at the same time, it is completely inadvisable”.
• Attention abuse and poor follow-up of antibiotic treatment which make the bacteria more and more resistant. “Antibiotic treatments should only be taken in case of bacterial infection, reminds the doctor. In addition, antibiotic treatment should never be interrupted prematurely at the risk of creating resistance.

What are the causes of nosocomial infections?

They are due to the presence of germs or bacteria in the establishment, and are transmitted in various ways : weakened immune defenses, spread by skin contact or cross transmission between patients or via staff, contamination of the hospital environment (water, air, equipment, food)… Among the reasons that favor the development of these infections, several things must be taken into account:

• The hospital, just like our home or any other place, has its own bacteriological life. If the basic rules of hygiene (gloves, masks, disinfection of equipment, surfaces, etc.) make it possible to create a barrier to infections, they are not always sufficient. “Gold, when a patient goes to a hospital, it is often that he himself is sicktherefore more fragile than in time normal, with probably weakened immunity. It is put in contact with a different bacterial flora of his to which he is therefore more sensitiveexplains the doctor. Statistically, you are more likely to catch something in the hospital when you are sick than at home when you are healthy.“

• The bacteria found in the hospital are generally more resistant than the ones we have at home.

• “In the hospital, the patients are generally under treatment (chemotherapy, antibiotic therapy, hormone therapy, etc.). These treatments tend to profoundly unbalance the patient’s intestinal microbiota, which makes it more vulnerable to a potentially aggressive foreign bacterium. It is also possible that this bacterium was already present in the patient’s microbiota before his hospitalization but was not expressed, adds Dr. Tafazzoli. The problem is thatwe will never know if the bacterium was caught in the hospital or before, but legally, the infection will be classified as a nosocomial disease.“

• With the increase in life expectancy, there are more and more very old people who are healthy carriers of a large number of resistant bacteria with which they have been in contact during their lifetime. “During hospitalization, these people are likely to transmit one of these bacteria to a younger person, who will not be immunized against them.

Bacterial infections can be spread by skin contact, airborne, by droplets (postillions), orofecal transmission (to the toilet), cross transmission between patients or via staff, or by contamination of the hospital environment (water, air, equipment, food)…

What are the symptoms of a nosocomial infection?

“The nosocomial infection is not a disease, but it is a bacterial or viral infection among many others, recalls Dr. Tafazzoli. There are therefore as many symptoms as possible nosocomial infections.“Among the dreaded infections are the multi-resistant bacilli, including for example Clostridium difficult, responsible for inflammatory diarrhea that last more than 10 days with fever. “This bacterium is complicated to treat, it is resistant and can create significant lesions in the intestine. It can even be lethal.” The infections contracted most frequently by patients are often urinary infections “often in the elderly, whose hygiene is difficult to control and poly-medicated”. Come next sepsis and surgical wound infections.

Time to onset of nosocomial infection

An identified infection is considered nosocomial if it appears at least 48 hours after entering the facility. This deadline is extended to 30 days when the infection occurs at the site where surgery was performed, and is increased to 1 year in case of
installation of foreign material: prosthesis, heart valve, pacemaker…

Thanks to Dr Jean Tafazzoli, general practitioner in Lyon, president at MaQuestionMédicale.fr.