Chavasse D C, Shier R P, Murphy O A, Huttly S R, Cousens S N, Akhtar T
London School of Hygiene and Tropical Medicine, London, UK.
Lancet. 1999 Jan 2;353(9146):22-5. doi: 10.1016/s0140-6736(98)03366-2.
Several million children are killed each year by diarrhoeal diseases; preventive strategies appropriate for developing countries are vital. Despite strong circumstantial evidence that flies are vectors of diarrhoeal diseases, no convincing studies of the impact of fly control on diarrhoea incidence in developing countries have been reported. We undertook a randomised study of the effect of insecticide spraying on diarrhoea incidence.
Six study villages were randomly assigned to two groups. Flies were controlled through insecticide application in group A in 1995 and in group B in 1996. In 1997 the effectiveness of baited fly traps was tested in group A villages. Diarrhoea episodes were monitored in children under 5 years through mothers' reports during weekly visits by a health visitor. Fly density was monitored by use of sticky fly-papers hung in sentinel compounds.
During the fly seasons (March-June) of both 1995 and 1996, insecticide application practically eliminated the fly population in the treated villages. The incidence of diarrhoea was lower in the sprayed villages than in the unsprayed villages in both 1995 (mean episodes per child-year 6.3 vs 7.1) and 1996 (4.4 vs 6.5); the reduction in incidence was 23% (95% CI 11-33, p=0.007). At times other than the fly season there was no evidence of a difference, in diarrhoea morbidity between sprayed and unsprayed villages. Fly density data for 1997 indicate the ineffectiveness of baited traps in this setting.
Fly control can have an impact on diarrhoea incidence similar to, or greater than, that of the interventions currently recommended by WHO for inclusion in diarrhoeal disease control programmes in developing countries. This important finding needs confirmation in other settings in developing countries. Technologies and practices that interrupt disease transmission by flies need to be developed and promoted.
每年有几百万儿童死于腹泻疾病；适合发展中国家的预防策略至关重要。尽管有充分的间接证据表明苍蝇是腹泻疾病的传播媒介，但尚无关于发展中国家控制苍蝇对腹泻发病率影响的有说服力的研究报告。我们开展了一项关于杀虫剂喷洒对腹泻发病率影响的随机研究。
六个研究村庄被随机分为两组。1995年在A组村庄通过喷洒杀虫剂来控制苍蝇，1996年在B组村庄进行。1997年在A组村庄测试了诱饵捕蝇器的效果。通过保健访视员每周访视时母亲的报告来监测5岁以下儿童的腹泻发作情况。通过悬挂在哨点房屋中的粘蝇纸监测苍蝇密度。
在1995年和1996年的苍蝇季节（3月至6月），喷洒杀虫剂几乎消除了处理过的村庄中的苍蝇数量。在1995年（每个儿童年的平均发作次数6.3对7.1）和1996年（4.4对6.5），喷洒杀虫剂的村庄腹泻发病率均低于未喷洒的村庄；发病率降低了23%（95%置信区间11 - 33，p = 0.007）。在苍蝇季节以外的其他时间，没有证据表明喷洒和未喷洒村庄的腹泻发病率存在差异。1997年的苍蝇密度数据表明在这种环境下诱饵捕蝇器无效。
控制苍蝇对腹泻发病率的影响可能与世界卫生组织目前推荐纳入发展中国家腹泻疾病控制项目的干预措施相似或更大。这一重要发现需要在发展中国家的其他环境中得到证实。需要开发和推广能够阻断苍蝇传播疾病的技术和做法。
