关键词: 尿路感染, 儿童, 膀胱输尿管反流

Abstract: Urinary tract infection（UTI）is one of common infectious diseases in children，which refers to the disease with symptoms of urinary tract infection and significant growth of a single type of bacteria in urine culture，and the most common pathogen is Gram's negative intestinal bacteria（E.coli accounts for more than 80%）.UTI includes upper urinary tract infection（pyelonephritis），lower urinary tract infection（cystitis and urethritis）and asymptomatic bacteriuria.The clinical manifestations are age-related，and in infants less than 2 years old，they are not typical and it may be unexplained fever.In physical examination and medical history inquiry， attention should be paid to whether there are risk factors for complicated UTI.The diagnosis can be confirmed if there is significant growth of single bacteria in urine analysis and suitable urine specimen culture. For primary UTI， ultrasonic examination of kidney and bladder is necessary. For recurrent UTI，further imaging examinations should be performed to rule out vesicoureteral reflux（VUR）and CAKUT，and oral antibiotics should be the main treatment.A short course of 3-5 days’ treatment is needed for lower urinary tract infection and a sequential course of treatment is needed for upper urinary tract infection with 7-14 days of intravenoussensitive antibiotics followed by oral treatment.At the same time，it is very important to treat potential vesico-intestinal dysfunction and lower urinary tract dysfunction.Since high-grade VUR is a risk factor for UTI and renal scarring，long-term antibiotic prophylaxis is required.

Key words: urinary tract infections, child, vesicoureteral reflux