Infectious diseases – Healthcare-associated infections

Staphylococcus aureus is the most common cause of healthcare-associated blood culture–positive infections – incidence on the rise

Staphylococcus aureus is the most common cause of hospital-associated blood culture–positive infections, meaning severe systemic infections. In 2024, a total of 2,041 blood culture–positive infections were reported to the national healthcare-associated infections register. There were altogether 2,264 microbial findings, of which 523, or 23.1 percent, were caused by S. aureus (2015: 345/1935; 17.8%).

The incidence of blood culture–positive infections caused by S. aureus has gradually increased: in 2024, the incidence was 0.26/1,000 patient-days, whereas the corresponding figure for 2015 was 0.18/1,000 patient-days (FIGURE 1). In 2024, the national surveillance covered nearly two million patient-days in somatic specialized medical care. Overall, healthcare-associated blood culture–positive infections caused by different microbes occur at a rate of about 1/1,000 patient-days, but the incidence varies greatly between patient groups — the highest number of infections occurs in the specialty of oncology.

National surveillance of surgical site infections focuses on hip and knee arthroplasty

National surveillance of surgical site infections is most comprehensive in hip and knee arthroplasty. In 2024, the surveillance included over 11,000 hip and over 12,000 knee arthroplasty procedures.

The prevalence of infections related to primary hip arthroplasty was 1.2 percent and in knee arthroplasty 0.8 percent — prevalence has remained at the same level for several years.

As of 2024, national surveillance of surgical site infections includes only severe infection types, i.e. deep incisional infections and organ/space infections. The surveillance period for surgical site infections has also been updated to align with international definitions. The surveillance period for surgical site infection is 30 days. If a foreign body, such as a joint prosthesis, is implanted, the surveillance period is 90 days from 2024 onward (previously one year).

The incidence of healthcare-associated Clostridioides difficile infections has turned downward again – severe infections remain rare

The incidence of Clostridioides difficile infections has, after an increase during 2021–2022, begun to decline again. In 2024, 495 hospital-acquired C. difficile infections were reported to the national healthcare-associated infections register. The incidence was 0.36/1,000 patient-days.

C. difficile is the most common cause of antibiotic-associated diarrhea. The severity of infection can vary from mild diarrhea to life-threatening pseudomembranous colitis. There were 19 severe C. difficile infections in 2024 that led to colectomy, intensive care, or death. There were 76 C. difficile infections that resulted in hospital readmission.

Indicators for infection prevention have been developed in national surveillance – observation of hand hygiene practices has become more common

The number of infection control nurses in relation to the number of hospital beds has remained at the same level compared with previous years.

Hand rub consumption has increased during several consecutive surveillance periods. In 2023, hand rub consumption was lower than in previous years both in specialized medical care overall (including intensive care units) and in somatic wards within specialized medical care.

All wellbeing services counties observe hand hygiene practices in specialized medical care, providing a better picture of hand hygiene compliance than monitoring hand rub consumption alone. The number of observed hand hygiene indications has been monitored in 2022 and 2023, and the numbers appear to be increasing.

The majority of units monitor antimicrobial consumption. Written guidelines for antimicrobial use are widely available.

Dive deeper into the dataset

The surveillance data are reported using THL’s summary and cube interface (TIKU). Public reporting consists of annual surveillance data from all hospitals participating in the surveillance, and individual hospital results cannot be identified from the report.

The closed reporting intended for hospitals participating in the surveillance includes the hospital’s own surveillance data at annual and monthly levels, as well as the combined surveillance data of all participating hospitals.

In addition to time series comparisons, hospitals can compare their own prevalence figures with those of other hospitals through so‑called ranking reports.

Access to reports presenting the results of an individual hospital is restricted to designated members of the participating hospital’s infection prevention and control unit. The results of an individual hospital will not be published without a separate agreement with the hospital.

Background information

Instructions for submitting data
Privacy notice: Healthcare-Associated Infections Register
Healthcare-Associated Infection Surveillance – Infection Prevention Measures Survey

Source

The data are compiled from the Healthcare-Associated Infections Register.

Statistical description

THL maintains the national Healthcare-Associated Infections Register for the purposes of surveillance, prevention, statistics, and research. The Healthcare-Associated Infections Registers and the data to be reported to them are defined in section 36 of the Communicable Diseases Act (1227/2016).

Data for healthcare-associated infection surveillance are collected from patient records, microbiological laboratory findings, and clinical observations. Data collection is carried out in hospitals by infection prevention professionals, infection control nurses, and infectious disease physicians.

Information on resources for infection prevention is collected annually in each wellbeing services county and reported to THL via the Infection Prevention Measures Survey.

Update schedule

The information on this page will next be updated in autumn 2026.