Author:
Lee Pei-Wen,Liu Chia-Tai,Rampao Herodes Sacramento,do Rosario Virgilio E,Shaio Men-Fang
Abstract
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.
Publisher
Springer Science and Business Media LLC
Subject
Infectious Diseases,Parasitology
Reference38 articles.
1. Pinto J, Sousa CA, Gil V, Ferreira C, Goncalves L, Lopes D, Petrarca V, Charlwood JD, do Rosario VE: Malaria in São Tomé and Príncipe: parasite prevalences and vector densities. Acta Trop. 2000, 76: 185-193. 10.1016/S0001-706X(00)00100-5.
2. Ceita JGV: Malaria in São Tomé and Príncipe. Proceedings of the Conference on Malaria in Africa. Edited by: Buck AA. 1986, Washington DC, American Institute of Biological Sciences, 142-155.
3. Tseng LF, Chang WC, Ferreira MC, Wu CH, Rampao HS, Lien JC: Rapid control of malaria by means of indoor residual spraying of alphacypermethrin in the Democratic Republic of São Tomé and Príncipe. Am J Trop Med Hyg. 2008, 78: 248-250.
4. Teklehaimanot HD, Teklehaimanot A, Kiszewski A, Rampao HS, Sachs JD: Malaria in São Tomé and Príncipe: on the brink of elimination after three years of effective antimalarial measures. Am J Trop Med Hyg. 2009, 80: 133-140.
5. Shaio MF: Um programa bem sucedido de controle da malaria na Africa. IV Encontro de Medicina Tropical dos Paises de Lingua Portuguesa e XLV Congresso da Sociedade Brasileira de Medicina Tropical. 2009
Cited by
47 articles.
订阅此论文施引文献
订阅此论文施引文献,注册后可以免费订阅5篇论文的施引文献,订阅后可以查看论文全部施引文献