title: Preventing malaria transmission by indoor residual spraying in Malawi: grappling with the challenge of uncertain sustainability.
abstract: 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.
  
  
  METHODS
  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 A methodical assessment of published and unpublished documents was conducted via a literature search of online electronic databases.
  
  
  CONCLUSIONS
  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.
authors.affiliation: Malaria Vector Control Consultant, Lusaka, Zambia. emmanuel_chanda@yahoo.co.uk.
authors.forename: Emmanuel
authors.initials: E
authors.lastname: Chanda
authors.affiliation: Malaria Alert Centre, Chichiri, Blantyre, Malawi. tmzilahowa@mac.medcol.mw.
authors.forename: Themba
authors.initials: T
authors.lastname: Mzilahowa
authors.affiliation: Ministry of Health, National Malaria Control Programme, Lilongwe, Malawi. chiphwanyajohn@yahoo.com.
authors.forename: John
authors.initials: J
authors.lastname: Chipwanya
authors.affiliation: Ministry of Health, National Malaria Control Programme, Lilongwe, Malawi. shadmulenga@yahoo.com.
authors.forename: Shadreck
authors.initials: S
authors.lastname: Mulenga
authors.affiliation: Ministry of Health, National Malaria Control Programme, Lilongwe, Malawi. alidoreen@yahoo.com.
authors.forename: Doreen
authors.initials: D
authors.lastname: Ali
authors.affiliation: USAID/PMI, Country Office, Lilongwe, Malawi. ptroell@usaid.gov.
authors.forename: Peter
authors.initials: P
authors.lastname: Troell
authors.affiliation: World Health Organization, Country Office, Lilongwe, Malawi. dodoliw@who.int.
authors.forename: Wilfred
authors.initials: W
authors.lastname: Dodoli
authors.affiliation: Malaria Vector Control Consultant, Nelspruit, Mpumalanga, South Africa. goverej@gmail.com.
authors.forename: John M
authors.initials: JM
authors.lastname: Govere
authors.affiliation: Centers for Disease Control and Prevention, Atlanta, GA, USA. hzg1@cdc.gov.
authors.forename: John
authors.initials: J
authors.lastname: Gimnig
mesh_terms: D000818:Animals; D000852:Anopheles; D006798:Housing; D006801:Humans; D007303:Insect Vectors; D007305:Insecticide Resistance; D007306:Insecticides; D016778:Malaria, Falciparum / Q000517:prevention & control*; D008295:Malawi; D009032:Mosquito Control; D009946:Organothiophosphorus Compounds; D010963:Plasmodium falciparum / Q000502:physiology*
chemical_list: D007306:Insecticides; D009946:Organothiophosphorus Compounds; C014153:pirimiphos methyl