Protecting houses with screening measures can substantially decrease both the numbers of malaria-carrying mosquitoes and the prevalence of malaria-related anaemia in children in those homes. The findings are reported in an Article published Online First and in an upcoming edition of The Lancet, written by Dr Matthew J Kirby, Durham University, UK (now at Wageningen University, The Netherlands), and Professor Steve W Lindsay, Durham University, UK (now at the London School of Hygiene and Tropical Medicine [LSHTM], UK), and colleagues at the Medical Research Council's (MRC) Laboratories in The Gambia and the LSHTM. The study was funded by the MRC.
The authors looked at two types of house screening— either full screening of windows, doors, and closing eaves and other holes where mosquitoes could enter; or installation of screened ceilings only. They assessed whether either could prevent house entry of mosquitoes and reduce anaemia in children in an area of seasonal malaria transmission—in this case, Farafenni town in The Gambia. A total of 462 houses were studied (full screening 188; screened ceilings 178; no screening 96). Mosquitoes that entered the homes were caught using traps.
The researchers found that the numbers of mosquitoes in the houses fell by 49% (screened ceilings) and 59% (full screening). Children in either partly screened or fully-screened homes were around half as likely to have malaria-related anaemia as those in unscreened properties. The authors say: "House screening could be easily incorporated into integrated vector management programmes, and because it does not rely on insecticides, it could be particularly beneficial in areas where insecticide resistance develops...We would encourage the initiation of a larger trial to assess whether this intervention reduces clinical episodes of malaria in diverse settings, including areas where use of insecticide-treated bednets is high. We also hope that the results of our trial will stimulate the development of additional sustainable methods that, in combination with improved health care and access to treatment, can help to strengthen efforts to eliminate malaria."
In an accompanying Comment, Dr Laurence Slutsker, and Dr John E Gimnig, Centers for Disease Control and Prevention, Atlanta, GA, USA, say that house screening to prevent malaria historically may have contributed more to malaria control and elimination than previously thought. However, further research is needed to determine when and how this strategy should be integrated with other vector control interventions such as long-lasting insecticide-treated bednets (LLINs) to provide added (or synergistic) benefits.
Dr Matthew J Kirby, formerly Durham University, UK (during the study), now at Wageningen University, The Netherlands. T) +255 (0) 788489055E) mkirby@ihi.or.tz
For Professor Steve W Lindsay, formerly Durham University, UK (during the study), now at the London School of Hygiene and Tropical Medicine, UK, please call LSHTM Press Office T) +44 (0) 20 7927 2073/2802 E) Steve.Lindsay@lshtm.ac.uk / gemma.howe@lshtm.ac.uk
Dr Laurence Slutsker, and Dr John E Gemming, Centers for Disease Control and Prevention, Atlanta, GA, USA. T) +1 770-488-7789 E) Laurence.slutsker@cdc.hhs.gov
For full Article and Comment, see: http://press.thelancet.com/housescreening.pdf
Journal
The Lancet