Urinary tract infection in outpatients in Germany – a cross-sectional study of diagnostics and susceptibility testing in medical laboratories

Background Urinary tract infections (UTIs) are common, representing a frequent cause of antibiotic prescription in primary care worldwide. Selection of antibiotics for antimicrobial susceptibility testing and the reporting of test results by laboratories can directly impact antibiotic prescribing and guideline adherence.

Aim To assess the current practice of susceptibility testing by laboratories for outpatient UTIs in Germany.

Design & setting A cross-sectional study was conducted including all laboratories identified by searching for specialists in laboratory medicine and microbiology on the websites of the 17 German associations of statutory health insurance physicians.

Method Between January - April 2024, a survey using a standardised questionnaire was conducted across identified laboratories.

Results Of the 396 laboratories identified, 65.2% (n=258) replied. Of these, 106 laboratories performed susceptibility testing and on average tested for 13.1 (SD 3.6) different antibiotics in a urine culture positive for E. coli. The most commonly tested antibiotics were ciprofloxacin (98.1%), cotrimoxazole (97.2%), cefuroxime and nitrofurantoin (both 91.5%). On average, laboratories tested 3.8 of the five antibiotics recommended in the German guidelines on uncomplicated UTI, with 26.4% testing for all five. Laboratories received clinical information on previous treatments and comorbidities in an estimated one-fifth (on average 21.3% and 21.5%, respectively) of the urine samples, and information on the type of the urine sample in an estimated three-fifths (63.7%) of samples.

Conclusion Laboratories should test and report as many first-line antibiotics as possible. Further, a more detailed and standardised transfer of clinical information to laboratories could enhance the quality of antibiotic prescribing.