The research team, led by Wenjing Wang and colleagues, searched PubMed, Scopus, and Web of Science for studies published since 2014, applying the rigorous standards of the PRISMA reporting framework and registering the protocol prospectively with PROSPERO under registration number CRD42025648170. Their aim was deceptively simple but methodologically demanding: to estimate pooled incidence and prevalence of urinary tract infections across different healthcare settings, and then to dissect those estimates by geography, infection setting, and host risk profile. The final dataset included 969,476 participants, a scale that lends considerable statistical weight to the pooled estimates.

The headline finding concerns the stark divide between hospital-acquired and community-acquired infections. Hospital-acquired urinary tract infections, abbreviated HAUTIs in the study, showed a pooled incidence proportion of 0.17, with a 95 percent confidence interval of 0.13 to 0.22, and a pooled prevalence of 0.21, with a confidence interval of 0.16 to 0.25. By comparison, community-acquired urinary tract infections showed a pooled incidence of just 0.08, with a confidence interval of 0.06 to 0.10. In practical terms, roughly one in five hospitalised patients in the included studies had or acquired a urinary tract infection, a figure that underscores how the hospital environment itself, with its invasive devices, immunocompromised patients, and dense microbial ecology, amplifies infection risk.

Within the hospital setting, the single most dangerous factor identified was the urinary catheter. Catheter-associated urinary tract infections emerged as a particularly high-risk category, which is consistent with the well-understood biology of these devices. An indwelling catheter provides bacteria with a direct conduit into the bladder, bypassing the natural flushing action of urination and forming a biofilm on its surface that shields microbes from both immune defences and antibiotics. The meta-analysis confirms that this device-related pathway remains a dominant driver of nosocomial urinary infection, and that catheter stewardship, meaning the avoidance, early removal, and meticulous management of urinary catheters, must sit at the centre of any prevention strategy.

Geography mattered as much as setting. The burden of hospital-acquired urinary tract infections was highest in Asia, Africa, and South America, a pattern that likely reflects a combination of factors including differences in healthcare infrastructure, catheterisation practices, antibiotic access, and surveillance capacity across regions. The authors argue that this regional variation exposes a central weakness in current infection control thinking: a uniform, one-size-fits-all prevention approach cannot adequately serve settings whose baseline risks, resources, and microbial ecologies differ so dramatically. Tailored protocols calibrated to local epidemiology, they suggest, are the realistic path forward.

On the microbiological front, the analysis confirmed what clinical microbiologists have long observed: gram-negative bacteria, and particularly Escherichia coli, dominate the etiology of urinary tract infections. Escherichia coli’s specialised adaptations for the urinary tract, including adhesive pili that bind to bladder epithelial cells and an ability to persist intracellularly, make it an exceptionally effective uropathogen. The predominance of gram-negative organisms carries practical consequences, because rising antimicrobial resistance in this bacterial group, particularly extended-spectrum beta-lactamase production, increasingly constrains empiric treatment choices in many regions.

Beyond setting and geography, the study systematically catalogued host-level risk factors, identifying gender, age, comorbidities, and prior disease history as consistent predictors of infection. Some of the most striking quantitative results came from specific vulnerable populations. Among kidney transplant recipients, those who experienced delayed graft function, a complication in which the transplanted kidney does not immediately work properly, faced a risk ratio of 1.63 for urinary tract infection, with a confidence interval of 1.19 to 2.22. This makes biological sense: impaired graft function alters urinary flow and immune regulation, and transplant patients are simultaneously subjected to immunosuppressive drugs that blunt their defences against bacterial invasion.

Pregnant women formed another clearly delineated high-risk group. The analysis found that lower educational attainment among pregnant women was associated with an elevated risk of urinary tract infection, with a pooled effect estimate of 0.40 and a confidence interval of 0.16 to 0.63. Pregnancy itself predisposes to urinary infection through hormonal relaxation of the ureters and mechanical compression of the urinary tract by the growing uterus, which slows urine flow and allows bacteria more time to establish themselves. Untreated infections in pregnancy can escalate to pyelonephritis and are associated with adverse outcomes for both mother and fetus, which is why identifying modifiable social determinants of risk, such as access to health education, carries real public health value.

The study also highlighted the elderly and people with diabetes as key vulnerable groups. Diabetes impairs immune function and, when poorly controlled, glycosuria creates a nutrient-rich environment in the urine that favours bacterial growth. Ageing, meanwhile, brings anatomical and physiological changes, incomplete bladder emptying, and higher rates of catheterisation and institutional care, all of which compound infection risk. By quantifying these risks within a single analytical framework, the review provides clinicians and policymakers with a stratified map of exactly where preventive effort should be concentrated, rather than spreading resources thinly across the entire patient population.

The broader significance of this work lies in its framing. Rather than treating urinary tract infections as a single homogeneous disease, the authors demonstrate that the burden is sharply stratified by where a patient is treated and who the patient is. That insight supports the development of risk-stratified infection control protocols: aggressive catheter reduction programmes and surveillance in hospitals, targeted screening and education for pregnant women, heightened vigilance in transplant units, and tailored prevention for diabetic and elderly patients. As antimicrobial resistance narrows the treatment options available for gram-negative uropathogens, preventing infections in the first place becomes not merely a convenience but a necessity. This meta-analysis, synthesising evidence from nearly a million people across continents and care settings, offers the clearest evidence yet of where that prevention effort must be aimed.

Subject of Research: Global epidemiology and risk-stratified burden of urinary tract infections across healthcare settings and high-risk populations

Article Title: Risk-stratified epidemiology and global burden of urinary tract infections across healthcare and high-risk populations: a systematic review and meta-analysis

Article References: Wang, W., Huo, N., Ma, H., Li, X., & Wang, Y. (2026). Risk-stratified epidemiology and global burden of urinary tract infections across healthcare and high-risk populations: a systematic review and meta-analysis. BMC Infectious Diseases. https://doi.org/10.1186/s12879-026-14395-z

Image Credits: AI Generated

DOI: 10.1186/s12879-026-14395-z

Keywords: urinary tract infection, hospital-acquired infection, catheter-associated UTI, meta-analysis, Escherichia coli, kidney transplant, pregnancy, diabetes, infection control, antimicrobial resistance, global health burden, risk factors