Here are a few article abstracts from PubMed on mosquito nets and indoor spraying; I have edited for length, indicated by "..." and commented or elaborated in []:
>From Eritrea, 2006: http://www.ncbi.nlm.nih.gov/pubmed/16635265?ordinalpos=35&itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pubmed_RVDocSum A steep decline of malaria morbidity and mortality trends in Eritrea between 2000 and 2004: the effect of combination of control methods...This study employed cross-sectional survey to collect data from households, community and health facilities on coverage and usage of Insecticide-Treated Nets (ITNs), Indoor Residual Spraying (IRS), larvicidal activities and malaria case management. Comparative data was obtained from a similar survey carried out in 2001...In the period 2000-2004, approximately 874,000 ITNs were distributed and 13,109 health workers and community health agents were trained on malaria case management. In 2004, approximately 81% households owned at least one net, of which 73% were ITNs and 58.6% of children 0-5 years slept under a net...IRS coverage increased with the combined amount of DDT and Malathion used rising from 6,444 kg, in 2000 to 43,491 kg, in 2004, increasing the population protected from 117,017 to 259,420. Drug resistance necessitated regimen change to chloroquine plus sulfadoxine-pyrimethamine. During the period, there was a steep decline in malaria morbidity and case fatality by 84% and 40% respectively. Malaria morbidity was strongly correlated to the numbers of ITNs distributed...and the amount (kg) of DDT and Malathion used for IRS... >From the Solomon Islands, 2004 [full article avail.]: http://www.ncbi.nlm.nih.gov/pubmed/15331840?ordinalpos=1&itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pubmed_RVDocSum The incidence of malaria in Solomon Islands has been decreasing since 1992. The control program used a combination of methods including DDT residual house spraying and insecticide-treated mosquito nets. To determine how much each method contributed to malaria control, data were analyzed on monthly incidence and on control activities for 41 of 110 malaria zones over the same time period (January 1993 to August 1999). After correction for endogeneity, then spraying, insecticide treatment of nets, and education about malaria are all independently associated with reduction in incident cases of malaria or fever, while larviciding with temephos is not. The evidence suggests that although impregnated bed nets cannot entirely replace DDT spraying without substantial increase in incidence, their use permits reduced DDT spraying. The paper shows that non-experimental data can be used to infer causal links in epidemiology, provided that instrumental variables are available to correct for endogeneity. >From a trial of bifenthrin treated mosquito nets in India (2005, full article avail.): http://www.ncbi.nlm.nih.gov/pubmed/15713980?ordinalpos=1&itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pubmed_RVAbstractPlusDrugs1 The main rural malaria vector Anopheles culicifacies has developed resistance to dichloro diphenyl trichloroethane (DDT), hexachloro cyclo hexane (HCH) and malathion in the state of Haryana in northern India. An alternative synthetic pyrethroid insecticide bifenthrin was therefore evaluated on mosquito nets against anopheline and culicine mosquitoes, in two villages...Two formulations of bifenthrin, suspension concentrate (SC) and micro-emulsion (ME) were compared with micro-capsule suspension (CS) of lambdacyhalothrin. The impact of three doses of bifenthrin (10, 25 and 50 mg/m(2)) [also untreated controls]...Efficacy of treated nets on mosquito density was assessed by calculating mosquito entry rate, immediate mortality, delayed mortality and excito-repellency to the insecticides...Bioassays on treated nets against A. culicifacies recorded 100 per cent mortality up to tenth fortnight for all the doses of impregnation with bifenthrin (SC and ME) and lambdacyhalothrin (CS). Ring-net bioassays against An. culicifacies showed median knock-down time between 3.1 to 11.4 min. Behavioural indices...reduction in entry rates of anopheline and culicine mosquitoes into the rooms with treated nets compared to control indicated good efficacy...Indoor (immediate) mortality of mosquitoes with bifenthrin ME formulation was relatively lower compared to SC fomulation of bifenthrin and based on delayed mortility and continued susceptibility in bioassays, bifenthrin ME at the rate of 10 mg/m(2) dose was found suitable for the impregnation of mosquito nets for phase III trial. Another 2005 from India; this includes indoor DDT spraying as one branch: http://www.ncbi.nlm.nih.gov/pubmed/16134977?ordinalpos=29&itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pubmed_RVDocSum A field trial was carried out...on the efficacy of mosquito nets treated with a tablet formulation of deltamethrin (K-O TAB) against malaria vectors. Treated nets were used in one village, and in the two control villages, one used untreated nets and the other used indoor spraying with DDT, without nets...Bioassays repeated on domestically used nets over 7 months showed persistence of almost 100% mortality of An. fluviatilis, whereas An. culicifacies showed a decline from 100% to 71% mortality over this period...The sum of collections of mosquitoes resting in village houses and those in exit traps and dead on floor sheets showed a reduction in the numbers of the two vector species due to the treated nets, compared with untreated or no nets, but no reduction in other anophelines or Culex species...Treated and untreated nets reduced the proportion of anophelines that had blood-fed; the treated nets did so more effectively than the untreated in the case of An. culicifacies and of Culex mosquitoes... [I don't see figures for the DDT controls in this abstract.] >From 2004, ?Pakistan [Allahabad cantonment area]. http://www.ncbi.nlm.nih.gov/pubmed/16509253?ordinalpos=21&itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pubmed_RVDocSum The study was undertaken to evaluate the impact of deltamethrin impregnated mosquito nets on malaria incidence, mosquito density, any adverse side effect among users and collateral effects on bed bugs and houseflies. A field trial was carried out over a period of three years in two adjacent military stations...keeping one as a trial and other as a control station. During first year, baseline data were collected and during next two years residual spray was replaced with use of deltamethrin impregnated mosquito nets in trial station. The use of deltamethrin-treated bed nets resulted in a significant decline in malaria incidence and annual parasite index (API). The average mosquito density of anopheline mosquitoes decreased by 67.8% and culicine by 49.7%. The insecticide was found safe for use amongst troops and had favourable collateral effects against bed bugs and flies. Use of deltamethrin impregnated bed nets has beneficial impact on integrated control of malaria. [?Use of indoor spraying part of "integrated control"?] >From Boloivia, 2007: http://www.ncbi.nlm.nih.gov/pubmed/17940319?ordinalpos=39&itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pubmed_RVDocSum ...A double blind, placebo controlled cluster-randomised clinical study. SETTING: Rural villages and peri-urban districts in the Bolivian Amazon. PARTICIPANTS: 4008 individuals in 860 households. INTERVENTIONS: All individuals slept under treated nets; one group also used a plant based insect repellent each evening, a second group used placebo...We analysed 15,174 person months at risk and found a highly significant 80% reduction in episodes of P vivax in the group that used treated nets and repellent (incidence rate ratio 0.20, 95% confidence interval 0.11 to 0.38, P<0.001). Numbers of P falciparum cases during the study were small and, after adjustment for age, an 82% protective effect was observed, although this was not significant (0.18, 0.02 to 1.40, P=0.10)... This 2005 Vietnamese study documents a significant decline in malarial disease, but "effects of the interventions could not be discerned with statistical significance." [?] http://www.ncbi.nlm.nih.gov/pubmed/15807800?ordinalpos=40&itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pubmed_RVDocSum The National Malaria Control Program (NMCP) in Vietnam is based on application of insecticide-treated bed nets (ITNs), spraying of insecticides and early microscopic diagnosis of malaria and treatment (EDTM) with artemisinin drugs. This study explores the implementation of the NMCP at provincial level and its impact on malaria incidence (mi) and prevalence in Binh Thuan in southern Vietnam... Control activities focused on the highly endemic zones where ITNs were distributed free of charge to ethnic minority groups, including twice yearly re-impregnation, from 1992 onwards. This almost completely replaced insecticide spraying. Complete ITN coverage of these groups was achieved in 1995, constituting 40% of the entire population... Before 1994, mi peaked to over 50/1000, pi to over 16% in the highly endemic zones. In 1998, these had decreased to below 9/1000 and 4% respectively. The effects of the interventions could not be discerned with statistical significance. CONCLUSION: Malaria incidence and prevalence declined significantly in Vietnam, possibly due to the malaria control efforts, but coinciding with rapid socioeconomic changes. My interpretation: Treated nets, properly used, are highly effective in reducing malarial disease; many areas require additional control measures such as indoor spraying. Education of the population at risk and coordinated use of healthcare workers region-wide is essential to success. Ongoing research for vector control and new antimicrobials is also essential as mosquitos become pesticide-resistant (see multiple cites in others' posts) and Plasmodium also develops drug resistance (this is well-documented; I can find cites if you wish). Debbi who spent way the heck more time on this than the ponies' state of muddiness recommended! :) ____________________________________________________________________________________ Looking for last minute shopping deals? Find them fast with Yahoo! Search. http://tools.search.yahoo.com/newsearch/category.php?category=shopping _______________________________________________ http://www.mccmedia.com/mailman/listinfo/brin-l
