Article in Japanese

Urinary tract infection caused by Haemophilus parainfluenzae in a child with urinary tract abnormality: A case report

Ryuji HASUNUMA^{1, 2)}, Kenichi TAKESHITA¹⁾, Haruka HISHIKI¹⁾, Naruhiko ISHIWADA³⁾, Hiromichi HAMADA²⁾, Setsuo OTA¹⁾

Haemophilus parainfluenzae is one of the bacteria usually colonized in human nasopharynx. It sometimes causes respiratory tract infections, but rarely urinary tract infections. This study reported a case of upper urinary tract infection caused by H. parainfluenzae in a 17-month-old girl with urinary tract abnormality. She had a history of upper urinary tract infection caused by Escherichia coli with bilateral hydronephrosis when she was 12 months old. She visited this hospital after two days of fever and grumpiness during urination. As she had pyuria, she was diagnosed with upper urinary tract infection and hospitalized. Haemophilus-like gram-negative short bacilli were found on her urine smear, and H. parainfluenzae was isolated from the urine culture. She was treated with cefotaxime and ampicillin intravenously, and amoxicillin orally for 5, 2 and 3 days, respectively. Since her renal function did not improve, and her hydronephrosis was aggravated after discharge, she was referred to a pediatric urologist who found genitourinary sinus in her urinary tract. H. parainfluenzae rarely causes urinary tract infection, therefore it is important to select appropriate culture medium for identifying this bacterium. Urinary tract infection caused by H. parainfluenzae is often accompanied by urinary tract malformations, therefore, close examination of the urinary tract is necessary.

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1）Department of Pediatrics, Teikyo University Chiba Medical Center
2）Department of Pediatrics, Graduate School of Medicine, Chiba University
3）Department of Infectious Diseases, Medical Mycology Research Center, Chiba University

Key words	Haemophilus parainfluenzae, urinary tract infection, urinary tract abnormality, hydronephrosis
Received	July 1, 2023
Accepted	December 2, 2023

36 (1)：27─32,2024