Killeen Gerry F, Smith Tom A, Ferguson Heather M, Mshinda Hassan, Abdulla Salim, Lengeler Christian, Kachur Steven P
Ifakara Health Research and Development Centre, Ifakara, Morogoro, United Republic of Tanzania.
PLoS Med. 2007 Jul;4(7):e229. doi: 10.1371/journal.pmed.0040229.
Malaria prevention in Africa merits particular attention as the world strives toward a better life for the poorest. Insecticide-treated nets (ITNs) represent a practical means to prevent malaria in Africa, so scaling up coverage to at least 80% of young children and pregnant women by 2010 is integral to the Millennium Development Goals (MDG). Targeting individual protection to vulnerable groups is an accepted priority, but community-level impacts of broader population coverage are largely ignored even though they may be just as important. We therefore estimated coverage thresholds for entire populations at which individual- and community-level protection are equivalent, representing rational targets for ITN coverage beyond vulnerable groups.
Using field-parameterized malaria transmission models, we show that high (80% use) but exclusively targeted coverage of young children and pregnant women (representing <20% of the population) will deliver limited protection and equity for these vulnerable groups. In contrast, relatively modest coverage (35%-65% use, with this threshold depending on ecological scenario and net quality) of all adults and children, rather than just vulnerable groups, can achieve equitable community-wide benefits equivalent to or greater than personal protection.
Coverage of entire populations will be required to accomplish large reductions of the malaria burden in Africa. While coverage of vulnerable groups should still be prioritized, the equitable and communal benefits of wide-scale ITN use by older children and adults should be explicitly promoted and evaluated by national malaria control programmes. ITN use by the majority of entire populations could protect all children in such communities, even those not actually covered by achieving existing personal protection targets of the MDG, Roll Back Malaria Partnership, or the US President's Malaria Initiative.
随着世界努力为最贫困人群创造更美好的生活,非洲的疟疾预防工作值得特别关注。经杀虫剂处理的蚊帐(ITN)是非洲预防疟疾的一种切实可行的手段,因此到2010年将覆盖率扩大到至少80%的幼儿和孕妇是千年发展目标(MDG)不可或缺的一部分。将个人防护目标对准弱势群体是公认的优先事项,但更广泛的人群覆盖在社区层面产生的影响在很大程度上被忽视了,尽管这些影响可能同样重要。因此,我们估算了整个人口的覆盖率阈值,在该阈值下个人层面和社区层面的防护效果相当,这代表了针对弱势群体之外的ITN覆盖率的合理目标。
通过使用实地参数化的疟疾传播模型,我们发现,对幼儿和孕妇(占人口比例不到20%)进行高覆盖率(80%的使用率)但仅针对特定群体的覆盖,将为这些弱势群体提供有限的保护和平等性。相比之下,对所有成年人和儿童,而不仅仅是弱势群体,进行相对适度的覆盖(使用率为35%-65%,该阈值取决于生态情景和蚊帐质量),可以实现等同于或大于个人防护的全社区公平效益。
要大幅减轻非洲的疟疾负担,需要覆盖整个人口。虽然仍应优先覆盖弱势群体,但国家疟疾控制项目应明确推广和评估大龄儿童和成年人广泛使用ITN所带来的公平和社区效益。整个人口中的大多数人使用ITN可以保护此类社区中的所有儿童,即使是那些未实际达到千年发展目标、抗击疟疾伙伴关系或美国总统疟疾倡议现有个人防护目标覆盖范围的儿童。