Abdulla S, Gemperli A, Mukasa O, Armstrong Schellenberg J R M, Lengeler C, Vounatsou P, Smith T
Ifakara Health Research and Development Centre (IHRDC), Ifakara, Tanzania.
Trop Med Int Health. 2005 Jan;10(1):11-8. doi: 10.1111/j.1365-3156.2004.01354.x.
Randomized controlled trials have shown that insecticide-treated nets (ITNs) have an impact on both malaria morbidity and mortality. Uniformly high coverage of ITNs characterized these trials and this resulted in some protection of nearby non-users of ITNs. We have now assessed the coverage, distribution pattern and resultant spatial effects in one village in Tanzania where ITNs were distributed in a social marketing programme. The prevalence of parasitaemia, mild anaemia (Hb <11 g/dl) and moderate/severe anaemia (Hb <8 g/dl) in children under five was assessed cross-sectionally. Data on ownership of ITNs were collected and inhabitants' houses were mapped. One year after the start of the social marketing programme, 52% of the children were using a net which had been treated at least once. The ITNs were rather homogeneously distributed throughout the village at an average density of about 118 ITNs per thousand population. There was no evidence of a pattern in the distribution of parasitaemia and anaemia cases, but children living in areas of moderately high ITN coverage were about half as likely to have moderate/severe anaemia (OR 0.5, 95% CI: 0.2, 0.9) and had lower prevalence of splenomegaly, irrespective of their net use. No protective effects of coverage were found for prevalence of mild anaemia nor for parasitaemia. The use of untreated nets had neither coverage nor short distance effects. More efforts should be made to ensure high coverage in ITNs programmes to achieve maximum benefit.
随机对照试验表明，经杀虫剂处理的蚊帐（ITN）对疟疾发病率和死亡率均有影响。这些试验的特点是ITN覆盖率普遍较高，这也为附近未使用ITN的人群提供了一定保护。我们现在评估了坦桑尼亚一个村庄的ITN覆盖率、分布模式及由此产生的空间效应，该村庄通过社会营销项目分发了ITN。对5岁以下儿童的寄生虫血症、轻度贫血（血红蛋白<11 g/dl）和中度/重度贫血（血红蛋白<8 g/dl）患病率进行了横断面评估。收集了ITN拥有情况的数据，并绘制了居民房屋地图。社会营销项目启动一年后，52%的儿童使用了至少经过一次处理的蚊帐。ITN在整个村庄分布较为均匀，平均密度约为每千人口118顶。寄生虫血症和贫血病例的分布没有明显模式，但生活在ITN覆盖率中等偏高地区的儿童患中度/重度贫血的可能性约为一半（比值比0.5，95%置信区间：0.2，0.9），脾肿大患病率也较低，无论其是否使用蚊帐。未发现覆盖率对轻度贫血患病率或寄生虫血症有保护作用。使用未经处理的蚊帐既没有覆盖率效应也没有近距离效应。应做出更多努力，确保ITN项目的高覆盖率，以实现最大效益。
