Epidemiology of Invasive Escherichia coli Disease in Adults Using Routine Healthcare Records from the United States,...

Extraintestinal pathogenic Escherichia coli can infect normally sterile body sites, causing invasive E. coli disease (IED). The IED burden is often underestimated. Here, we provide more insights into the real-world epidemiology of IED in the United States from 2002 to 2022.

In this retrospective cohort study, a narrow and a broad algorithm composed of coded diagnoses combined with laboratory data (microbiology culture) were first validated against the gold-standard IED case definition. The algorithms were selected to identify IED cases among adults in the Kaiser Permanente Northwest database. IED incidence rates (IRs) and case fatality rates (CFRs) were calculated and stratified by period, age, and sex. The risk of IED in the population with pre-defined comorbidities, including urinary tract infections (UTIs), was assessed using incidence rate ratios.

A source population of 1,163,319 and 1,169,224 persons was identified by the narrow and broad algorithms, respectively. In these populations, 5832 (narrow algorithm) and 10,490 (broad algorithm) IED cases were identified, corresponding to an IED IR of 80.9 (95% confidence interval [CI]: 78.8-83.0) and 145.8 (143.0-148.6) cases per 100,000 person-years, respectively. The IR was higher among females than males and increased with age and over time. All-cause mortality among cases at 30 days after IED diagnosis was 7.6% (95% CI: 6.9-8.3%) and 7.2% (6.7-7.7%) based on the narrow and broad algorithms, respectively, and CFRs increased with age to 13.1% (both algorithms) among ≥ 80-year-olds. Having a history of UTIs was confirmed as an independent risk factor, multiplying the risk of IED by more than five compared to the population without a history of UTIs.

These observations demonstrate that IED is a substantial and growing global health concern that disproportionally affects older adults.