High rate of antibiotic use for asymptomatic bacteriuria found at VA clinics

News brief

Doctor analyzing urinary sample — *ElMiguelacho / iStock*

A study conducted at Department of Veterans Affairs (VA) outpatient clinics found that antibiotic prescribing for asymptomatic bacteriuria (ASB) is prevalent, researchers reported yesterday in the American Journal of Infection Control.

For the retrospective cohort study, researchers from VA hospitals in Pennsylvania, Ohio, and Illinois reviewed medical charts from outpatient visits at any VA medical center from January 2019 through December 2022 that were associated with a positive urine culture collected within 3 days before or after the visit. They categorized the visits into three groups based on urinary tract infection (UTI)–specific symptoms (UTI-present, UTI-unlikely, and UTI-absent) and looked at which visits received antibiotics and why.

The objective of the study was to assess the current state of inappropriate antibiotic prescribing for ASB—the presence of bacteria in urine with no specific symptoms of UTI—at VA outpatient clinics. Although the Infectious Diseases Society of America and other groups advocate against routine ASB screening and treatment because of clinical ineffectiveness and concerns about increased risk of antimicrobial resistance, studies suggest that inappropriate antibiotic prescribing for ASB persists in many US outpatient settings.

Prescribing driven by urine test results

Of the 484 medical charts reviewed, 258 (53%) were categorized as UTI-present, and 113 (23%) each as UTI-unlikely and UTI-absent. Most (90%) of the UTI-present visits resulted in antibiotic prescriptions, and 66% of the UTI-absent and 58% of UTI-unlikely visits also received antibiotic prescriptions.

In 37.6% of the UTI-absent and 26.7% of the UTI-unlikely visits that resulted in antibiotic prescriptions, the provider appeared to be prescribing in response to urinalysis or urine culture results. For 18.4% of these prescriptions, the provider cited an inappropriate symptom as indicative of UTI.

Chart review also revealed several occasions in which urine tests were ordered by providers with no discernable clinical reason for collecting a urine sample.

The study authors say the findings indicate that a significant proportion of veterans experienced unnecessary antibiotic exposure and show that continued use of urine testing appears to be driving unnecessary treatment.

"Improving diagnostic stewardship in the ordering of urinalysis and urine cultures could represent a critical first step in reducing inappropriate ASB prescribing," they wrote.

Bangladesh and India alert WHO about new H5N1 infections

News brief

Lisa Schnirring

In a monthly zoonotic flu update, the World Health Organization (WHO) said Bangladesh and India have reported new H5N1 avian flu cases that were previously unreported.

Bangladesh’s patient is a child from Chittagong division in the country’s southeast who was admitted to the hospital on May 21, where a respiratory sample was collected. Symptoms included fever, diarrhea, and mild respiratory symptoms. The sample tested positive for H5 on May 28, and the neuraminidase was confirmed later as N1.

An investigation revealed the child had contact with backyard poultry before symptoms began. No other cases were detected, and the child has recovered. The illness marks Bangladesh’s 11^th human H5N1 case since 2008 and its third of 2025.

In June, the WHO noted the two cases reported earlier this year, both of them children from Khulna division in the southwestern part of the country. Both recovered from their infections. Today’s report on the new cases didn’t note the clade, but the two cases reported earlier this year involved the older 2.3.2.1a, known to circulate in birds and poultry in Bangladesh and India.

Details sparse about India’s case

The WHO said India’s case involves a man from Karnataka state whose sample was obtained in May and has since died from his infection. Few details were available about his exposure. However, the report said the virus belongs to the 2.3.2.1a clade known to circulate in Bangladesh and India.

India reported its last case in April, which involved a 2-year-old girl from Andhra Pradesh state who died from her infection.

Editor's note: This story was updated on July 16 to add clarification from the WHO that India's patient is from Karnataka state.

Canadian hospitals seeing exponential increase in superbug incidence

News brief

Chris Dall, MA

Carbapenem-resistant Enterobacterales — Stephanie Rossow / CDC

Surveillance data from a network of Canadian acute-care hospitals suggests that the incidence of carbapenemase-producing Enterobacterales (CPE) infection and colonization is low but increasing exponentially, according to a study published last week in Antimicrobial Resistance and Infection Control.

Using data from the Canadian Nosocomial Infection Surveillance Program (CNISP), a team led by researchers with the Public Health Agency of Canada analyzed eligible CPE isolates submitted by participating hospitals from 2010 through 2023, along with microbiologic data and data on patient characteristics and outcomes.

A previous analysis of CNISP data from 2010 through 2014 found no significant increase in incidence of CPE, which are resistant to multiple antibiotic classes, but increasing trends in CPE incidence have been reported in Canadian hospitals in recent years.

A total of 138 CPE infections were reported by 97 hospitals in 2023, for an incidence rate of 0.14 per 10,000 patient-days, up from 0.03 per 10,000 patient-days in 2010. CPE colonization incidence rose from 0.02 to 0.78 per 10,000 patient-days over the same period.

The analysis also identified rising rates of healthcare-associated (HA) CPE infections from 2019 through 2023 (0.05 to 0.09 per 10,000 patient-days), primarily from 7 hospitals that accounted for 53% of all HA-CPE infections in 2023.

Carbapenemases were most frequently detected in Escherichia coli (29%), Klebsiella pneumoniae (22%), and Enterobacter cloacae complex (16%). The most frequently identified carbapenemase families were bla_KPC (46%), bla_NDM (29%), and bla_OXA-48 (16%).

Hospital transmission is driving the increase

The median age of patients was 67 years, and pre-existing comorbidities were common (84%). Thirty-day all-cause mortality was 19%. Most patients did not report international travel (66%) or receipt of medical care abroad (74%)—two factors that have previously been associated with CPE infection and colonization.

The study authors say the observed exponential growth is a warning that current infection-control measures in Canadian hospitals are insufficient to prevent CPE transmission.

"Our findings suggest that nosocomial transmission is driving the recent increase in CPE incidence in Canada," they wrote. "Improved infection control measures and antimicrobial stewardship as well as access to newer antimicrobials are all urgently needed."