Combination of malaria vector control interventions in pyrethroid resistance area in Benin: a cluster randomised controlled trial
Combination of malaria vector control interventions in pyrethroid resistance area in Benin: a cluster randomised controlled trial
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DOI：
10.1016/s1473-3099(12)70081-6
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发表时间：
2012-08-01
影响因子：
56.3
通讯作者：
Henry, Marie-Claire
中科院分区：
文献类型：
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作者：
Corbel, Vincent;Akogbeto, Martin;Henry, Marie-Claire
背景寄生虫对抗疟药物和病媒对杀虫剂产生抗药性，这对非洲的疟疾控制和消灭工作提出了挑战。我们调查了是否结合长效杀虫蚊帐（LLINs）与室内滞留喷洒（IRS）或氨基甲酸酯处理的塑料布（CTPS）赋予增强保护，防止疟疾和更好的管理拟除虫菊酯耐药性的vectors.Methods比LLINs单独，我们做了一个集群随机对照试验，在贝宁南部，西非的28个村庄。那些村庄的纳入标准是疟疾媒介对拟除虫菊酯的中等水平抗性，村庄之间的最小距离为2 km。我们评估了四种疟疾病媒控制干预措施：LLIN针对孕妇和6岁以下儿童的目标覆盖率（TLLIN，参考组），LLIN所有睡眠单元的普遍覆盖率（ULLIN），TLLIN加上每8个月施用一次的氨基甲酸酯-IRS的全面覆盖率（TLLIN+IRS），以及ULLIN加上排到家庭墙壁上部的CTPS的全面覆盖率（ULLIN+CTPS）。干预措施是在初步调查的基础上通过区组随机分配到各个村庄的，每个村庄的儿童都是随机选择的，参加的人数是由计算机生成的。主要终点是6岁以下儿童恶性疟原虫临床疟疾的发病密度率，通过Poisson回归分析，考虑到年龄和抽样设计的影响，采用广义估计方程方法。临床和寄生虫学信息是通过在连续6天的12个周期内（每6周一次）对疟疾发作进行主动病例检测和对无症状疟原虫感染进行横断面调查获得的。儿童或研究者未对研究组设盲。本研究在当前对照试验中注册，编号ISRCTN 07404145。结果在评估的58个村庄中，28个被随机分配到干预组。每个干预组共随访413-429名儿童，随访时间为18个月。ULLIN组儿童的疟疾临床发病率密度没有降低（发病密度率0.95，95% CI 0.67-1.36，p=0.79），TLLIN+IRS组也未发生（1.32，0.90-1.93，p=0.15）或ULLIN+CTPS组（1.05，0.75-1.48，p=0.77）与参考组（TLLIN）相比。无症状感染的患病率和寄生虫密度（非显著回归系数）观察到相同的趋势。解释没有显着的好处，减少疟疾发病率，感染和传播时，结合LLIN+IRS或LLIN+CTPS相比，LLIN覆盖的背景。这些研究结果对国家疟疾控制方案很重要，应有助于设计更具成本效益的疟疾控制和消除战略。
Background Malaria control efforts and elimination in Africa are being challenged by the development of resistance of parasites to antimalarial drugs and vectors to insecticides. We investigated whether the combination of long-lasting insecticidal mosquito nets (LLINs) with indoor residual spraying (IRS) or carbamate-treated plastic sheeting (CTPS) conferred enhanced protection against malaria and better management of pyrethroid-resistance in vectors than did LLINs alone.Methods We did a cluster randomised controlled trial in 28 villages in southern Benin, west Africa. Inclusion criteria of the villages were moderate level of pyrethroid resistance in malaria vectors and minimum distance between villages of 2 km. We assessed four malaria vector control interventions: LLIN targeted coverage to pregnant women and children younger than 6 years (TLLIN, reference group), LLIN universal coverage of all sleeping units (ULLIN), TLLIN plus full coverage of carbamate-IRS applied every 8 months (TLLIN+IRS), and ULLIN plus full coverage of CTPS lined up to the upper part of the household walls (ULLIN+CTPS). The interventions were allocated to villages by a block randomisation on the basis of preliminary surveys and children of each village were randomly selected to participate with computer-generated numbers. The primary endpoint was the incidence density rate of Plasmodium falciparum clinical malaria in children younger than 6 years as was analysed by Poisson regression taking into account the effect of age and the sampling design with a generalised estimating equation approach. Clinical and parasitological information were obtained by active case detection of malaria episodes during 12 periods of 6 consecutive days scheduled at six weekly intervals and by cross-sectional surveys of asymptomatic plasmodial infections. Children or study investigators were not masked to study group. This study is registered with Current Controlled Trials, number ISRCTN07404145.Findings Of 58 villages assessed, 28 were randomly assigned to intervention groups. 413-429 children were followed up in each intervention group for 18 months. The clinical incidence density of malaria was not reduced in the children from the ULLIN group (incidence density rate 0.95, 95% CI 0.67-1.36, p=0.79), nor in those from the TLLIN+IRS group (1.32, 0.90-1.93, p=0.15) or from the ULLIN+CTPS group (1.05, 0.75-1.48, p=0.77) compared with the reference group (TLLIN). The same trend was observed with the prevalence and parasite density of asymptomatic infections (non significant regression coefficients).Interpretation No significant benefit for reducing malaria morbidity, infection, and transmission was reported when combining LLIN+IRS or LLIN+CTPS compared with a background of LLIN coverage. These findings are important for national malaria control programmes and should help the design of more cost-effective strategies for malaria control and elimination.