Utility of the blood culture in infection of the urinary tract with fever in the elderly

Abstract

Introduction. Urinary tract infections are one of the most common community infections. The diagnosis of urinary infections in the elderly is complex because of its presentation and clinic. The aim of this article is to evaluate the usefulness of blood cultures in febrile urinary tract infection in elderly pa-tients, risk factors, causes of discordance between urine and blood cultures, usefulness of biomarkers and mortality. Material and methods: Observational study of patients admitted over 65 years old, with urinary infections. Results. A total of 216 episodes with urinary infections and blood cultures performed. 70 (32,4%) cases with bacter-emia. The most frequently detected isolates in blood cultures were: Escherichia coli 50 (71,4%) and Proteus spp. 6 (8,5%). Only septic shock was associated with a higher frequency of bacteraemia (OR=2,93, IC 95: 1,0-8,5; p=0,04). In 26 of the blood cultures a different isolation of the urine culture was detected. Overall mortality was 9.1%, with no association with the presence of bacteremia (p>0. 05). Conclusions: One third of elderly people hospitalized by tract urinary infection had bacteremia. Their detection was not associated with overall mortality. Disagree between blood and urine cultures in febrile is frequent, especially in patients with recent antibiotic treatment or recently hospitalized.