A randomised placebo-controlled trial of antibiotics to prevent urinary tract infection in children

这项研究需要确定一种常见的临床做法--对尿路感染(UTI)后儿童进行长期抗生素治疗--在预防进一步UTI方面是否安全有效，如果是，是否所有合适的儿童都在接受治疗。到高中年龄，UTI将影响大约10%的澳大利亚儿童(每年8.8万名儿童)。由于尿路感染可能会损害肾脏，因此对尿路感染儿童的管理重点一直是防止进一步感染。目前，这意味着通过肾道成像确定被认为是尿路感染复发风险最高的儿童。那些被发现有尿液从膀胱回流到肾脏的患者(约30%的尿路感染患者)随后被给予抗生素治疗2-5年。不幸的是，从来没有一个适当设计的试验来测试抗生素是否真的能预防尿路感染，如果是的话，反流儿童是否是合适的和唯一需要治疗的群体。由于皮肤、肠道和血液问题等副作用，以及可能产生抗药性的细菌，长期使用抗生素实际上可能弊大于利。这项研究的设计包括随机分配安慰剂或抗生素(复方新诺明，在这种情况下通常给予的抗生素)给大约800名首次出现症状的尿路感染儿童。这些儿童接受治疗并随访一年，以确定两组中进一步尿路感染的比率。两组儿童在结果上的任何差异都将是由于抗生素治疗的原因。这项研究可能会证明长期使用抗生素是无效的，因此不应该常规使用。在这种情况下，对儿童进行检查以检测膀胱输尿管返流的作用不大，应该放弃。或者，抗生素治疗可能被证明是预防进一步尿路感染的有效治疗方法，在这种情况下，这项研究将清楚地确定哪些儿童将受益。

This study is needed to determine whether a common clinical practice long-term antibiotic treatment for children following urinary tract infection (UTI) - is safe and effective in preventing further UTI and if so, whether all appropriate children are being treated. UTI will affect about 10% of Australian children by high school age (88,000 children per year). Because UTI may damage the kidneys, the management priority for children with UTI has been prevention of further infection. Currently this means the identification of children thought to be most at risk of recurrent UTI by renal tract imaging. Those found to have reflux of urine from the bladder to the kidney (present in about 30% of those with UTI) are then placed on antibiotics fro 2-5 years. Unfortunately there has never been a properly designed trial to test whether antibiotics do really prevent UTI and if so, whether children with reflux are the appropriate and only group requiring treatment. Long term antibiotics may in fact do more harm than good because of side effects like skin, bowel and blood problems and because resistant bacteria may develop. The design of this study involves the random allocation of placebo or antibiotic (cotrimoxazole, the usual antibiotic given in this case) to about 800 children after their first symptomatic UTI. These children are treated and followed for one year to determine the rate of futher UTI in both groups. Any difference in outcome between the two groups of children will be because of the antibiotic treatment. This study may prove long-term antibiotics are ineffective and therefore should not be routinely used. In this case investigation of children to detect vesicoureteric reflux would serve little purpose and should be abandoned. Alternatively antibiotic treatment may be shown as effective treatment for preventing further UTI and in this case the study will clearly identify those children who will benefit.