How much vector control is needed to achieve malaria elimination?

Abstract

Roll Back Malaria’s ambitious goals for global malaria reduction by 2015 represent a dilemma for National Malaria Control Programs (NMCPs) that are still far from malaria elimination. Current vector control efforts by NMCPs generally fall short of their potential, leaving many NMCPs wondering how much vector control it will take to achieve malaria elimination. We believe the answer is detailed in the relationships between the entomological inoculation rate (EIR) and four epidemiological measures of malaria in humans. To achieve adequate vector control NMCPs must evaluate EIRs to identify problematic foci of transmission and reduce annual EIRs to less than one infectious bite per person.

Entomologic Inoculation Rates of Anopheles arabiensis in Southwestern Ethiopia

“…The EIR has implications for monitoring the suitability of vector control interventions 4,8. Current malaria vector interventions such as LLINs and IRS reduce EIR in many malaria-endemic countries, but none of these interventions has managed to reduce EIR to < 1 ib/p/year,4 except in the Garki Project (which used propoxur for IRS) and reduced EIR only temporarily 40.…”

“…Estimation of the EIR is important for quantifying the potential level of human exposure to infected mosquitoes and for assessing the impact of interventions on malaria transmission in a given area 4,8. Many studies have reported huge variations in malaria transmission intensity in Africa,9 not only between urban and rural settings but even within the same locality 10.…”

Expanding Integrated Vector Management to promote healthy environments

“…Through the use of a rational evidence based decision-making process to utilize available resources in an optimal manner, IVM aims to make vector control more effective by use of economical and ecologically sound strategies [11]. IVM encourages integrative and multi-disease approaches to promote collaborative interventions [12] that better combat the spread of VBDs [13], but fails to address nuisance-biting arthropods that affect inherent quality of life. Furthermore, its common reactive application following vector outbreaks limits the entirety of potential preventative benefits; an additional environmental enhancement component would significantly improve IVM strategies’ capabilities to control all arthropods.…”

“…Given that arthropod vectors impact the health, agricultural, and environmental sectors, control through IVM strategies obliges local government and community involvement to implement goal-achieving interventions [13]. Vector control is an essential factor in improving public health and has the potential to alleviate poverty if fully exploited because disability-adjusted life years (DALYs) can be reduced [11].…”

Participatory risk mapping of malaria vector exposure in northern South America using environmental and population data

“…All Plasmodium parasites are transmitted to humans through the bite of several species of mosquitoes in the genus Anopheles and some dominant species are highly effective in transmitting malaria parasites (Sinka et al, 2010). While application of control measures aimed at limiting exposure to vectors such as use of insecticide treated nets (ITNs), indoor residual spraying (IRS), and early detection, diagnosis, and treatment have reduced malaria incidence in the region over the past decade, elimination of malaria remains elusive as uneven application of control measures may limit their effectiveness in reducing transmission (Ulrich et al, 2013). Further, anopheline vectors may develop insecticide resistance or behaviors that lead them to avoid control measures, thus making elimination in some areas extremely challenging (Govella et al, 2013).…”