The online version of this article (doi:10.1186/1475-2875-11-189) contains supplementary material, which is available to authorized users.
The authors declare that they have no competing interests.
BRM and SSN contributed to the planning, execution and supervision of laboratory and field activities, data analysis and drafting the manuscript, US performed the statistical analysis and contributed in preparing the first draft of the manuscript, DAP and KR planned the study and contributed in data interpretation and finalizing the manuscript. All authors contributed equally in preparing the final version of the text and have read and agreed to the manuscript.
In the present study, Interceptor®, long-lasting polyester net, 75 denier and bursting strength of minimum 250 kPa coated with alpha-cypermethrin @ 200 mg/m2 was evaluated for its efficacy in reducing the mosquito density, blood feeding inhibition and malaria incidence in a tribal dominated malaria endemic area in Chhattisgarh state, central India. Its durability, washing practices and usage pattern by the community was also assessed up to a period of three years.
The study was carried out in two phases. In the first phase (September 2006 to August 2007), 16 malaria endemic villages in district Kanker were randomized into three groups, viz. Interceptor net (LN), untreated polyester net (100 denier) and without net. Malaria cases were detected by undertaking fortnightly surveillance by home visits and treated as per the national drug policy. Mosquito collections were made by hand catch and pyrethrum space spray methods from human dwellings once every month. Slide positivity rate (SPR) and malaria incidence per 1000 population (PI) were compared between the three study arms to assess the impact of use of Interceptor nets. Simultaneously, wash resistance studies were carried out in the laboratory by doing cone bioassays on Interceptor LNs washed up to 20 times. Activities undertaken in second Phase (April 2008 to October 2009) after an interval of about 18 months post-net distribution included questionnaire based surveys at every six months, i.e. 18, 24, 30 and 36 months to observe durability, usage pattern of LNs and washing practices by the community. After 36 months of field use, 30 nets were retrieved and sampled destructively for chemical analysis.
Interceptor nets were found effective in reducing the density, parity rate and blood feeding success rate of main malaria vector Anopheles culicifacies as compared to that in untreated net and no net villages. SPR in LN villages was 3.7% as compared to 6.5% in untreated and 11% in no net villages. PI in LN villages was 16.4 in comparison to 24.8 and 44.2 in untreated polyester net and no net villages respectively. In surveys carried out after three years of initial distribution, 78.7% (737/936) nets were still in possession with the households, of which 68% were used every night. An. culicifacies mortality was >80% in cone bioassays done on LNs washed up to 20 times in laboratory. Mean alpha-cypermethrin content was 43.5 ± 31.7 mg/m2 on Interceptor LNs withdrawn after three years of household use against the baseline specification of 200 mg/m2. A gradual increase in the proportion of holed nets was observed with the increased period of usage.
Interceptor nets were highly effective in reducing vector densities as well as malaria incidence in the study villages. Availability of 78% nets with the households in usable condition clearly indicated durability of Interceptor LNs up to three years in the rural setting of India. The nets were found to contain an effective concentration of alpha-cypermethrin against malaria vector after three years of household use.
Authors’ original file for figure 112936_2012_2140_MOESM1_ESM.pdf
WHO: WHO recommended long-lasting insecticidal mosquito nets. 2011, World Health Organization, Geneva, Available from: http://www.who.int/whopes/Long_lasting_insecticidal_nets_Jan_2011.pdf
WHO: Report of the tenth WHOPES working group meeting. 2006, World Health Organization, Geneva, Available from http://whqlibdoc.who.int/hq/2007/WHO_CDS_NTD_WHOPES_2007_1_eng.pdf
Ansari MA, Razdan RK: Bio-efficacy and operational feasibility of alphacypermethrin (Fendona) impregnated mosquito nets to control rural malaria in northern India. J Vector Borne Dis. 2003, 40: 33-42. PubMed
Dev V, Raghavendra K, Singh SP, Phookan S, Khound K, Dash AP: Wash resistance and residual efficacy of long-lasting polyester netting coated with alpha-cypermethrin (Interceptor) against malaria-transmitting mosquitoes in Assam, northeast India. Trans R Soc Trop Med Hyg. 2010, 104: 273-278. 10.1016/j.trstmh.2009.08.010. CrossRefPubMed
Sharma SK, Upadhyaya AK, Haque MA, Tyagi PK, Raghavendra K, Dash AP: Wash-resistance and field evaluation of alpha-cypermethrin treated long-lasting insecticidal net (Interceptor®) against malaria vectors Anopheles culicifacies and Anopheles fluviatilis in a tribal area of Orissa, India. Acta Trop. 2010, 116: 24-30. 10.1016/j.actatropica.2010.05.002. CrossRefPubMed
Mosha FW, Lyimo IN, Oxborough RM, Matowo J, Malima R, Feston E, Mndeme R, Tenu F, Kulkarni M, Maxwell CA, Magesa SM, Rowland MW: Comparative efficacies of permethrin- deltamethrin- and alpha-cypermethrin-treated nets, against Anopheles arabiensis and Culex quinquefasciatus in northern Tanzania. Ann Trop Med Parasitol. 2008, 102: 367-376. 10.1179/136485908X278829. CrossRefPubMed
National Vector Borne Disease Control Programme: Malaria situation in India. Available from http://www.nvbdcp.gov.in/malaria-new.html
WHO: Malaria entomology and vector control, learner’s guide. World Health Organization, Geneva, Available from: http://whqlibdoc.who.int/hq/2003/WHO_CDS_CPE_SMT_2002.18_Rev.1_PartI.pdf
WHO: Guidelines for monitoring the durability of long-lasting insecticidal mosquito nets under operational conditions. World Health Organization, Geneva, Available on the internet at: http://whqlibdoc.who.int/publications/2011/9789241501705_eng.pdf
WHO: Guidelines for laboratory and field testing of long-lasting insecticidal mosquito nets. 2005, World Health Organization, Geneva, WHO/CDS/WHOPES/GCDPP/2005.11
WHO: WHO Specifications and evaluations for public health pesticides: Alpha-cypermethrin long-lasting (coated onto filaments) insecticidal net. http://www.who.int/whopes/quality/Alphacypermethrin_Interceptor_specs_eval_WHO_Oct_2009.pdf,
- Effectiveness and durability of Interceptor® long-lasting insecticidal nets in a malaria endemic area of central India
Rajendra M Bhatt
Shri N Sharma
Aditya P Dash
- BioMed Central
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