-Original-

Use of Fever Duration to Guide Management of Urinary Tract Infection

Takeshi Yanagihara^1,2, Koichi Kobayashi¹, Emi Yanai², Hikaru Takeshita², Yujiro Tanabe¹ and Yasuhiko Itoh¹

¹Department of Pediatrics, Nippon Medical School Hospital, Tokyo, Japan
²Department of Pediatrics, Nippon Medical School Musashi Kosugi Hospital, Kanagawa, Japan

Background: The appropriate duration of antimicrobial therapy for febrile urinary tract infection (fUTI) in children has not been established. This study examined the optimal duration of treatment for fUTI in children.
Methods: We created a protocol that used fever duration to determine the duration of antibiotic administration. Transvenous antibiotics were administered until 3 days after resolution of fever, followed by oral antibiotics for 1 week. Diagnosis of fUTI was based on a fever of 37.5°C or higher and a quantitative culture of catheterized urine yielded a bacteria count of ≥5 × 10⁴. Acute focal bacterial nephritis (AFBN) and pyelonephritis (PN) were diagnosed on the basis of contrast-enhanced computed tomography (eCT) findings. We retrospectively reviewed treatment outcomes.
Results: Of the 78 patients treated according to our protocol, data from 58 were analyzed-49 children (30 boys) had PN and nine (three boys) had AFBN. Blood test results showed that patients with AFBN had significantly higher white blood cell counts and C-reactive protein levels than did those with PN; however, urinary findings and causative bacteria did not differ between groups. Time to resolution of fever and duration of intravenous antibiotic administration were significantly longer in patients with AFBN than in those with PN. However, average duration of AFBN treatment was 14.2 days, which was shorter than the previously reported administration period of 3 weeks. No recurrence was observed in AFBN patients.
Conclusions: A protocol that used fever duration to determine the duration of antimicrobial treatment was useful. Invasive examinations, such as eCT, were not required.

J Nippon Med Sch 2024; 91: 190-197

Keywords
acute focal bacterial nephritis, child, contrast-enhanced computed tomography, intravenous antibiotic therapy, pyelonephritis

Correspondence to
Takeshi Yanagihara, Department of Pediatrics, Nippon Medical School Hospital, 1-1-5 Sendagi, Bunkyo-ku, Tokyo 113-8602, Japan
yagi@nms.ac.jp

Received, August 27, 2023
Accepted, October 25, 2023