普林西比岛消除疟疾前状况。

Pre-elimination of malaria on the island of Príncipe.

机构信息

The Anti-Malaria Team of Taiwan in São Tomé and Príncipe, São Tomé and Princípe, Taiwan.

出版信息

Malar J. 2010 Jan 20;9:26. doi: 10.1186/1475-2875-9-26.

DOI:10.1186/1475-2875-9-26

PMID:20089158

原文链接:https://pmc.ncbi.nlm.nih.gov/articles/PMC2823607/

Abstract

BACKGROUND

Plasmodium falciparum is the major species responsible for malaria transmission on the island of Príncipe, in the Republic of São Tomé and Príncipe (STP). Indoor residual spraying (IRS) has been intensively deployed on the island, since 2003. Other measures included intermittent preventive therapy (IPT), since 2004, as well as artemisinin-based therapy (ACT) and long-lasting insecticidal nets (LLINs) from 2005. The work was coordinated by the Ministry of Health of STP through their Centro Nacional de Endemias (CNE) and the impact of such an integrated control programme on the prevalence and epidemiology of malaria in Príncipe was evaluated.

METHODS

The scaling-up of preventive strategies included IRS, LLINs, IPT for pregnant women, as well as early diagnosis and prompt treatment with ACT. Regular implementation of an island-wide IRS programme was carried out yearly in 2003-2005, and later in 2008. Malaria incidence and prevalence were estimated based on passive case detection and active case detection, respectively. Slide positivity rate (SPR) was used as an indicator of any increase of malaria cases during and after the control programme was initiated.

RESULTS

Regular IRS achieved a coverage of 85-90% for each of the four annual cycles (2003-2005, annually and one spraying in 2008) while usage of LLINs was never superior to 50% from 2006-2009. Coverage of IPT steadily increased from 50% in 2004 to 80% in 2008. Since 2006, over 90% of uncomplicated malaria patients received ACT treatment. Severe malaria cases were hospitalized and treated with quinine. Monthly trends of SPR were constantly over 50% in 2003, but steadily decreased below 10% in 2006. SPR has been below 5% since 2007, but an increase to up to 15% was noted in June 2009 when 16 imported cases were detected. A steep decline by 99% of malaria incidence was observed between 2003 and 2008, with an incidence risk of the population of five per thousand, in 2008. No malaria mortality has been reported since 2005. Species shift from falciparum to non-falciparum malaria was noted after a five-year intensive control programme. Cross-sectional country-wide active surveillances showed malaria prevalences of 1.1%, 0.7%, and 0.9% in June 2006, Oct 2007, and July 2009, respectively, of which over 90% were asymptomatic.

CONCLUSION

The effective measures of the combination of four major control methods have produced a rapid decline in malaria morbidity and mortality on the island of Príncipe. The combination of IRS, IPT, and active surveillance with ACT treatment seemed to have played important roles to achieve a present status of low and stable malaria on the island. In low transmission settings, any increase of malaria morbidity indicates potential epidemics and assumes that current control strategies were interrupted. Active surveillance should be reinforced to follow and monitor all asymptomatic carriers and imported cases. Consolidation and a shift to elimination phase demands the sustainability of such integrated programmes.

摘要

背景

恶性疟原虫是圣多美和普林西比共和国（圣普）普林西比岛疟疾传播的主要物种。自 2003 年以来，该岛一直在密集部署室内滞留喷洒（IRS）。其他措施包括从 2004 年开始间歇性预防治疗（IPT），以及从 2005 年开始使用青蒿素为基础的疗法（ACT）和长效驱虫蚊帐（LLINs）。这项工作由圣普卫生部通过其国家流行病中心（CNE）协调，评估了这种综合控制方案对普林西比岛疟疾的流行和流行病学的影响。

方法

预防策略的扩大包括 IRS、LLINs、孕妇 IPT，以及及时诊断和使用 ACT 进行快速治疗。2003-2005 年每年进行一次常规的全岛 IRS 方案实施，并于 2008 年再次实施。疟疾发病率和患病率分别基于被动病例检测和主动病例检测进行估计。幻灯片阳性率（SPR）被用作疟疾病例在控制方案启动期间和之后任何增加的指标。

结果

IRS 每 4 年进行一次，每年进行一次，2008 年进行一次，每年的覆盖率达到 85-90%，而 LLINs 的使用率从未超过 2006-2009 年的 50%。IPT 的覆盖率从 2004 年的 50%稳步增加到 2008 年的 80%。自 2006 年以来，超过 90%的非复杂性疟疾患者接受了 ACT 治疗。严重疟疾病例住院并使用奎宁治疗。2003 年，每月的 SPR 趋势持续超过 50%，但在 2006 年稳步下降到 10%以下。自 2007 年以来，SPR 一直低于 5%，但 2009 年 6 月发现 16 例输入性病例时，SPR 上升至 15%。2003 年至 2008 年期间，疟疾发病率急剧下降了 99%，2008 年人口发病率为每千人 5 例。自 2005 年以来，没有报告疟疾死亡。经过五年的密集控制计划，疟原虫从恶性疟原虫向非恶性疟原虫转变。全国性的横断面主动监测显示，2006 年 6 月、2007 年 10 月和 2009 年 7 月的疟疾患病率分别为 1.1%、0.7%和 0.9%，其中超过 90%为无症状。

结论

岛上四种主要控制方法的有效措施迅速降低了疟疾的发病率和死亡率。IRS、IPT 和 ACT 治疗相结合的主动监测似乎在实现岛上目前低而稳定的疟疾状况方面发挥了重要作用。在低传播环境中，疟疾发病率的任何增加都表明存在潜在的流行，并假设当前的控制策略已经中断。应加强主动监测，以跟踪和监测所有无症状携带者和输入性病例。巩固和转向消除阶段需要这种综合方案的可持续性。