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Long lasting pyrethroid treated bednets are the most important tool for preventing malaria. Pyrethroid resistant Anopheline mosquitoes are now ubiquitous in Africa, though the public health impact remains unclear, impeding the deployment of more expensive nets. Meta-analyses of bioassay studies and experimental hut trials are used to characterise how pyrethroid resistance changes the efficacy of standard bednets, and those containing the synergist piperonyl butoxide (PBO), and assess its impact on malaria control. New bednets provide substantial personal protection until high levels of resistance, though protection may wane faster against more resistant mosquito populations as nets age. Transmission dynamics models indicate that even low levels of resistance would increase the incidence of malaria due to reduced mosquito mortality and lower overall community protection over the life-time of the net. Switching to PBO bednets could avert up to 0.5 clinical cases per person per year in some resistance scenarios.DOI: http://dx.doi.org/10.7554/eLife.16090.001

Summaryobjective To review the evidence on the link between malaria and poverty. methods Review of the published and grey literature to identify (i) the data available on the socio-economic distribution of malaria incidence and vulnerability, and (ii) the uptake of malaria control interventions.results We found mixed evidence on malaria incidence, with a number of studies identifying no relationship between socio-economic status and incidence, although a larger number of studies do find a link. There is strong evidence that uptake of preventive and treatment interventions is closely related to proxies for socio-economic status. More generally, the quality of the literature examining this issue is highly variable, with many different measures of socio-economic status and often inadequate descriptions of methods of data collection and analysis in relation to socio-economic status.conclusions Important socio-economic differentials exist in access to malaria interventions, increasing the vulnerability of the poorest. More information is needed about how other methods of delivering malaria treatment and prevention can redress these inequalities.

BackgroundAt present, large-scale use of two malaria vector control methods, long-lasting insecticidal nets (LLINs) and indoor residual spraying (IRS) is being scaled up in Africa with substantial funding from donors. A third vector control method, larval source management (LSM), has been historically very successful and is today widely used for mosquito control globally, except in Africa. With increasing risk of insecticide resistance and a shift to more exophilic vectors, LSM is now under re-evaluation for use against afro-tropical vector species. Here the costs of this intervention were evaluated.MethodsThe 'ingredients approach' was used to estimate the economic and financial costs per person protected per year (pppy) for large-scale LSM using microbial larvicides in three ecologically diverse settings: (1) the coastal metropolitan area of Dar es Salaam in Tanzania, (2) a highly populated Kenyan highland area (Vihiga District), and (3) a lakeside setting in rural western Kenya (Mbita Division). Two scenarios were examined to investigate the cost implications of using alternative product formulations. Sensitivity analyses on product prices were carried out.ResultsThe results show that for programmes using the same granular formulation larviciding costs the least pppy in Dar es Salaam (US$0.94), approximately 60% more in Vihiga District (US$1.50) and the most in Mbita Division (US$2.50). However, these costs are reduced substantially if an alternative water-dispensable formulation is used; in Vihiga, this would reduce costs to US$0.79 and, in Mbita Division, to US$1.94. Larvicide and staff salary costs each accounted for approximately a third of the total economic costs per year. The cost pppy depends mainly on: (1) the type of formulation required for treating different aquatic habitats, (2) the human population density relative to the density of aquatic habitats and (3) the potential to target the intervention in space and/or time.ConclusionCosts for LSM compare favourably with costs for IRS and LLINs, especially in areas with moderate and focal malaria transmission where mosquito larval habitats are accessible and well defined. LSM presents an attractive tool to be integrated in ongoing malaria control effort in such settings. Further data on the epidemiological health impact of larviciding is required to establish cost effectiveness.

Malaria, more than any other disease of major public health importance in developing countries, disproportionately affects poor people, with 58% of malaria cases occurring in the poorest 20% of the world's population. If malaria control interventions are to achieve their desired impact, they must reach the poorest segments of the populations of developing countries. Unfortunately, a growing body of evidence from benefit-incidence analyses has demonstrated that many public health interventions that were designed to aid the poor are not reaching their intended target. For example, the poorest 20% of people in selected developing countries were as much as 2.5 times less likely to receive basic public health services as the least-poor 20%. In the field of malaria control, a small number of studies have begun to shed light on differences by wealth status of malaria burden and of access to treatment and prevention services. These early studies found no clear difference in fever incidence based on wealth status, but did show significant disparities in both the consequences of malaria and in the use of malaria prevention and treatment services. Further study is needed to elucidate the underlying factors that contribute to these disparities, and to examine possible inequities related to gender, social class, or other factors. To achieve impact and overcome such inequities, malaria control efforts must begin to incorporate approaches relevant to equity in program design, implementation, and monitoring and evaluation.