Infections developed by patients while in hospitals declined by 30 per cent between 2009 and 2017, according to new research in CMAJ.
However, continued focus is necessary to identify and prevent emerging antimicrobial-resistant pathogens, and infections with medical devices, such as urinary or intravenous catheters.
Health care-associated infections are a substantial issue worldwide. In the United States, an estimated five per cent of patients admitted to hospital in 2002 developed an infection, resulting in 1.7 million infections and 98,000 deaths.
A series of studies, conducted by a team of researchers with the Canadian Nosocomial Infection Surveillance Program (CNISP), included data from hospitals from nine Canadian provinces in 2002 and 2009, and all 10 provinces in 2017.
The proportion of patients with a hospital-acquired infection increased from 9.9 per cent in 2002 to 11.3 per cent in 2009, and then decreased to 7.9 per cent in 2017.
Urinary tract infections (32 per cent) were the most common infection, followed by pneumonia (23 per cent), surgical site infection (20 per cent), bloodstream infection (15 per cent) and Clostridioides difficile infection (nine per cent). All infection types decreased in frequency in 2017.
Many reasons
"There is no single reason for the overall decline in infection types," said Geoffrey Taylor, a professor of infectious disease at the University of Alberta who helped lead the study.
"Canadian hospitals have taken multiple steps which have proven effective. For example, many hospitals now monitor hand hygiene, and we've been able to show at our own hospital that adherence rates have gone up from the 60 per cent range to the high 80 per cent range."
Other interventions such as antimicrobial stewardship—ensuring antibiotics are used only when necessary—are being used effectively at hospitals across Canada as well, said Taylor.
Despite the progress, Taylor believes there are concerning trends Canadian health authorities need to be aware of moving forward.
Researchers found that device-associated infections such as ventilator-associated pneumonia, catheter-associated urinary tract infections and surgical site infections accounted for 35 per cent of all health care-associated infections in 2017. More will need to be done to address the safety of the devices in the future, noted Taylor.
The study also showed that while infections caused by antimicrobial-resistant organisms remain relatively uncommon, their prevalence has increased.
In 2002 the antibiotic resistant rate in Canadian hospitals was 4.7 per cent. By 2009 the rate had increased to 6.2 per cent and then jumped again to 8.8 per cent in 2017.
"We're concerned that antibiotic resistance is becoming a bigger problem in Canadian hospitals and more will need to be done to both monitor the situation and prevent it from getting worse," said Taylor. "As resistance becomes more widespread, infection obviously becomes more difficult to treat. While we still see far fewer occurrences than in some other countries, the growing number of cases bears careful watching."
The study, "Trends in Health Care-Associated Infections in Acute Care Hospitals in Canada: An Analysis of Repeated Point-Prevalence Surveys," was published Sept. 9.
The Public Health Agency of Canada provided funding for the Canadian Nosocomial Infection Surveillance Program.
—with files from Kim Barnhart
