Centre de Recherche entomologique de Cotonou (CREC), Cotonou, Benin.
Faculté des Sciences et Techniques, de l' Université d'Abomey-Calavi, Cotonou, Benin.
Malar J. 2020 Jan 28;19(1):45. doi: 10.1186/s12936-020-3131-1.
Since 2008, Indoor Residual Spraying (IRS) has been performed in Benin in 19 districts, including 4 in southern Benin, 9 in Atacora, and 8 in Atacora, Alibori and Donga in northern Benin. However, Benin still struggles with questions about IRS cost-benefit and epidemiological impact. Lessons learned and challenges from 10 years of IRS in Benin to be shared with the stakeholders involved in vector control implementation for decision-making.
Entomological parameters have been assessed entomological parameters in IRS communes since 2008. In all IRS intervention communes, decreases in human biting rate (HBR) of Anopheles gambiae, blood feeding inhibition and entomological inoculation rate (EIR) as compared to control district have been measured.
EIR was reduced by 80-90%, which is encouraging, but should be observed with caution because: (i) the reduction may be insufficient to decrease epidemiological indicators given that the residual EIR in IRS districts is still higher than it is in some regions of stable malaria; (ii) the reduction in EIR is based on comparisons with control communes, but it is difficult to select control areas with the same environmental characteristics as intervention areas; (iii) despite the reduction, half of all mosquitoes that entered IRS-treated houses succeeded in taking human blood meals. Further, there are behaviours among Benin's population that limit IRS efficacy, including recent data showing that > 90% of people are not protected by IRS between 7 and 10 p.m. This is due to the fact that they remain outdoors and that most people are not protected from mosquito bites after 10 p.m. because they either sleep outdoors without IRS protection or indoors without an ITN. Moreover, people have large amounts of clothing hanging on walls where mosquitoes can rest instead of IRS-treated walls. Finally, other components are important to consider in implementing IRS among which: (i) Vector resistance management strategies are sometimes poorly understood; this is actually different from the need to replace one insecticide with another after the emergence of resistance; (ii) African countries should prepare to finance IRS themselves.
To curtail residual malaria transmission, additional interventions able to target vectors escaping IRS should be prioritized.
自 2008 年以来，贝宁在 19 个地区开展了室内滞留喷洒（IRS）项目，包括贝宁南部的 4 个地区、阿塔科拉的 9 个地区以及北部的阿塔科拉、阿利博里和多哥的 8 个地区。然而，贝宁仍然存在关于 IRS 成本效益和流行病学影响的问题。本研究旨在分享贝宁 10 年来 IRS 的经验教训和挑战，为参与病媒控制实施的利益相关者提供决策依据。
自 2008 年以来，一直在进行 IRS 的地区进行了昆虫学参数评估。在所有 IRS 干预社区，与对照区相比，冈比亚按蚊的人血叮咬率（HBR）、吸血抑制率和昆虫接种率（EIR）均有所下降。
EIR 降低了 80-90%，这令人鼓舞，但应谨慎观察，因为：（i）鉴于 IRS 地区的残留 EIR 仍高于某些稳定疟疾地区，减少幅度可能不足以降低流行病学指标；（ii）EIR 的减少是基于与对照社区的比较，但很难选择与干预区具有相同环境特征的对照区；（iii）尽管有所减少，但仍有一半进入 IRS 处理房屋的蚊子成功吸食了人类血液。此外，贝宁的人口行为限制了 IRS 的效果，包括最近的数据表明，90%以上的人在晚上 7 点至 10 点之间没有得到 IRS 的保护。这是因为他们留在户外，大多数人在晚上 10 点后没有受到蚊子叮咬的保护，因为他们要么在没有 IRS 保护的情况下在户外睡觉，要么在没有 ITN 的情况下在室内睡觉。此外，人们在墙上挂了很多衣服，蚊子可以在那里休息，而不是在 IRS 处理过的墙上。最后，在实施 IRS 时还需要考虑其他因素，包括：（i）有时对媒介抗药性管理策略的理解不够；这实际上与在出现抗药性后需要用另一种杀虫剂替代不同；（ii）非洲国家应该准备好自行资助 IRS。
为了遏制残留疟疾的传播，应优先考虑针对逃避 IRS 的媒介的其他干预措施。
