Scale-up of integrated malaria vector control: lessons from Malawi.

PROBLEM: Indoor residual spraying and long-lasting insecticidal nets (LLINs) are key tools for malaria vector control. Malawi has struggled to scale up indoor residual spraying and to improve LLIN coverage and usage. APPROACH: In 2002, the Malawian National Malaria Control Programme developed guidelines for insecticide treated net distribution to reach the strategic target of at least 60% coverage of households with an LLIN. By 2005, the target coverage was 80% of households and the Global Fund financed the scale-up. The US President's Malaria Initiative funded the indoor residual spraying intervention. LOCAL SETTING: Malawi's entire population is considered to be at risk of malaria. Poor vector control, insecticide resistance in malaria vectors and insufficient technical and financial support have exacerbated the malaria burden. RELEVANT CHANGES: Between 2002 and 2012, 18 248 206 LLINs had been distributed. The coverage of at least one LLIN per household increased from 27% (3689/13 664) to 58% (1974/3404). Indoor residual spraying coverage increased from 28 227 to 653 592 structures between 2007 and 2011. However, vector resistance prompted a switch from pyrethroids to organophosphates for indoor residual spraying, which increased the cost and operations needed to be cut back from seven to one district. Malaria cases increased from 2 853 315 in 2002 to 6 748 535 in 2010, and thereafter dropped to 4 922 596 in 2012. LESSONS LEARNT: A single intervention-based approach for vector control may have suboptimal impact. Well-coordinated integrated vector management may offer greater benefits. A resistance management plan is essential for effective and sustainable vector control.

Preventing malaria transmission by indoor residual spraying in Malawi: grappling with the challenge of uncertain sustainability.

BACKGROUND: In the past decade, there has been rapid scale-up of insecticide-based malaria vector control in the context of integrated vector management (IVM) according to World Health Organization recommendations. Endemic countries have deployed indoor residual spraying (IRS) and long-lasting insecticidal nets as hallmark vector control interventions. This paper discusses the successes and continued challenges and the way forward for the IRS programme in Malawi. CASE DESCRIPTION: The National Malaria Control Programme in Malawi, with its efforts to implement an integrated approach to malaria vector control, was the 'case' for this study. Information sources included all available data and accessible archived documentary records on IRS in Malawi. A methodical assessment of published and unpublished documents was conducted via a literature search of online electronic databases. DISCUSSION: Malawi has implemented IRS as the main malaria transmission-reducing intervention. However, pyrethroid and carbamate resistance in malaria vectors has been detected extensively across the country and has adversely affected the IRS programme. Additionally, IRS activities have been characterized by substantial inherent logistical and technical challenges culminating into missed targets. As a consequence, programmatic IRS operations have been scaled down from seven districts in 2010 to only one district in 2014. The future of the IRS programme in Malawi is uncertain due to limited funding, high cost of alternative insecticides and technical resource challenges being experienced in the country. CONCLUSIONS: The availability of a long-lasting formulation of the organophosphate pirimiphos-methyl makes the re-introduction of IRS a possibility and may be a useful approach for the management of pyrethroid resistance. Implementing the IVM strategy, advocating for sustainable domestic funding, including developing an insecticide resistance monitoring and management plan and vector surveillance guidelines will be pivotal in steering entomologic monitoring and future vector control activities in Malawi.