The effect of malaria control on Plasmodium falciparum in Africa between 2000 and 2015
S Bhatt, D J Weiss, E Cameron, D Bisanzio, B Mappin, U Dalrymple, K Battle, C L Moyes, A Henry, P A Eckhoff, E A Wenger, O Briët, M A Penny, T A Smith, A Bennett, J Yukich, T P Eisele, J T Griffin, C A Fergus, M Lynch, F Lindgren, J M Cohen, C L J Murray, D L Smith, S I Hay, R E Cibulskis, P W Gething, S Bhatt, D J Weiss, E Cameron, D Bisanzio, B Mappin, U Dalrymple, K Battle, C L Moyes, A Henry, P A Eckhoff, E A Wenger, O Briët, M A Penny, T A Smith, A Bennett, J Yukich, T P Eisele, J T Griffin, C A Fergus, M Lynch, F Lindgren, J M Cohen, C L J Murray, D L Smith, S I Hay, R E Cibulskis, P W Gething
Abstract
Since the year 2000, a concerted campaign against malaria has led to unprecedented levels of intervention coverage across sub-Saharan Africa. Understanding the effect of this control effort is vital to inform future control planning. However, the effect of malaria interventions across the varied epidemiological settings of Africa remains poorly understood owing to the absence of reliable surveillance data and the simplistic approaches underlying current disease estimates. Here we link a large database of malaria field surveys with detailed reconstructions of changing intervention coverage to directly evaluate trends from 2000 to 2015, and quantify the attributable effect of malaria disease control efforts. We found that Plasmodium falciparum infection prevalence in endemic Africa halved and the incidence of clinical disease fell by 40% between 2000 and 2015. We estimate that interventions have averted 663 (542-753 credible interval) million clinical cases since 2000. Insecticide-treated nets, the most widespread intervention, were by far the largest contributor (68% of cases averted). Although still below target levels, current malaria interventions have substantially reduced malaria disease incidence across the continent. Increasing access to these interventions, and maintaining their effectiveness in the face of insecticide and drug resistance, should form a cornerstone of post-2015 control strategies.
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References
- World Health Organization . World Malaria Report 2014. World Health Organization; Geneva: 2014.
- Roll Back Malaria Partnership. World Health Organization . Global Malaria Action Plan 1 (2000-2015) World Health Organization; Geneva: 2008.
- World Health Organization . Global Technical Strategy for Malaria 2016–2030. World Health Organization; Geneva: 2015.
- Roll Back Malaria Partnership. World Health Organization . Action and Investment to Defeat Malaria 2016-2030. World Health Organization on behalf of the Roll Back Malaria Partnership Secretariat; Geneva: 2015.
- Rowe AK, et al. Caution is required when using health facility-based data to evaluate the health impact of malaria control efforts in Africa. Malar. J. 2009;8:209.
- Chizema-Kawesha E, et al. Scaling up malaria control in Zambia: Progress and impact 2005-2008. Am. J. Trop. Med. Hyg. 2010;83:480–488.
- Lim SS, et al. Net benefits: a multicountry analysis of observational data examining associations between insecticide-treated mosquito nets and health outcomes. PLoS Med. 2011;8:e1001091.
- Lengeler C. Insecticide-treated bed nets and curtains for preventing malaria. Cochrane database Syst. Rev. 2004:CD000363.
- Giardina F, et al. Effects of vector-control interventions on changes in risk of malaria parasitaemia in sub-Saharan Africa: a spatial and temporal analysis. Lancet Glob. Heal. 2014;2:e601–e615.
- Hay SI, et al. A world malaria map: Plasmodium falciparum endemicity in 2007. PLoS Med. 2009;6:e1000048.
- Gething PW, et al. A new world malaria map: Plasmodium falciparum endemicity in 2010. Malar. J. 2011;10:378.
- Noor AM, et al. The changing risk of Plasmodium falciparum malaria infection in Africa: 2000-10: a spatial and temporal analysis of transmission intensity. Lancet. 2014;383:1739–47.
- Patil AP, et al. Defining the relationship between Plasmodium falciparum parasite rate and clinical disease: statistical models for disease burden estimation. Malar. J. 2009;8:186.
- Griffin JT, Ferguson NM, Ghani AC. Estimates of the changing age-burden of Plasmodium falciparum malaria disease in sub-Saharan Africa. Nat. Commun. 2014;5:3136.
- Smith T, et al. Ensemble modeling of the likely public health impact of a pre-erythrocytic malaria vaccine. PLoS Med. 2012;9:e1001157.
- Hay SI, et al. Estimating the global clinical burden of Plasmodium falciparum malaria in 2007. PLoS Med. 2010;7:14.
- Diggle P, Ribeiro P. Model-based Geostatistics. Springer; New York: 2007.
- Weiss DJ, et al. Re-examining environmental correlates of Plasmodium falciparum malaria endemicity: a data-intensive variable selection approach. Malar. J. 2015;14:68.
- Smith DL, Guerra CA, Snow RW, Hay SI. Standardizing estimates of the Plasmodium falciparum parasite rate. Malar. J. 2007;6:131.
- Cameron E, et al. Defining the relationship between infection prevalence and clinical incidence of Plasmodium falciparum malaria. Nat. Commun. in press.
- Wenger EA, Eckhoff PA. A mathematical model of the impact of present and future malaria vaccines. Malar J. 2013;12:10.
- Battle KE, et al. Global database of Plasmodium falciparum and P.vivax incidence records. Sci. Data. 2015;2:150012.
- WorldPop WorldPop gridded population distributions. 2015 .
- Cibulskis RE, Aregawi M, Williams R, Otten M, Dye C. Worldwide incidence of malaria in 2009: estimates, time trends, and a critique of methods. PLoS Med. 2011;8:e1001142.
- Liu L, et al. Global, regional, and national causes of child mortality in 2000–13, with projections to inform post-2015 priorities: an updated systematic analysis. Lancet. 2014;385:430–440.
- Global, regional, and national age–sex specific all-cause and cause-specific mortality for 240 causes of death, 1990–2013: a systematic analysis for the Global Burden of Disease Study 2013. Lancet. 2014;385:117–171.
Source: PubMed