ITN Articles

Bednets and malaria in Africa — by Kurtis Taylor — last modified 2008-02-12 11:05

The Lancet 2001; 357:1219-1220 Many studies have shown that the burden of malaria in a community can be reduced by the use of insecticidetreated nets (ITNs). In Africa, four randomised trials, which had child mortality as the primary endpoint, found a reduction in deaths among children under 5 years of age with the use of ITNs (three trials) or insecticide-treated curtains.1 Although these results are encouraging, they pose additional questions. . . .

Community factors associated with malaria prevention by mosquito nets: an exploratory study in rural Burkina Faso — by Kurtis Taylor — last modified 2008-02-12 11:05

Malaria-related knowledge, attitudes and practices (KAP) were examined in a rural and partly urban multiethnic population of Kossi province in north-western Burkina Faso prior to the establishment of a local insecticide-treated bednet (ITN) programme. Various individual and group interviews were conducted, and a structured questionnaire was administered to a random sample of 210 heads of households in selected villages and the provincial capital of Nouna. . . .

Community Reactions to the Introduction of Permethrin-Treated Bed Nets for Malaria Control During A Randomized Controlled Trial in Western Kenya — by Kurtis Taylor — last modified 2008-02-12 11:05

Prior to implementation of a randomized controlled trial of insecticide (permethrin)-treated bed nets (ITNs) in western Kenya, ethnographic studies were conducted to understand local perceptions of disease, sleeping patterns, and other factors that might affect use of ITNs. Educational activities took place prior to distribution, but immediately after distribution in Asembo only approximately half of the ITNs were in use. A qualitative study was then conducted to identify the community’s perceptions about ITNs and the ITN project. While participants ranked malaria as important and recognized that malaria prevention could be beneficial, they believed ITNs would be only partly effective due to the perception that malaria has multiple causes. Concerns expressed included fear of the insecticide, thought by some to be a toxic family planning aid, the taking of blood during clinical studies, and the mixing up of family ITNs during net re-treatment, which would violate cultural taboos. Attempts were made to allay fears by improved communication on these subjects and modification of the study design. . . .

Delivery of insecticide-treated net services through employer and community-based approaches in Kenya — by Kurtis Taylor — last modified 2008-02-12 11:05

Background and objectives Many approaches have been used to deliver insecticide-treated nets (ITNs) to African communities in different settings. Between 1992 and 2002, the African Medical and Research Foundation (AMREF), Kenya, used two ITN delivery models: the employer-based approach and the community-based approach. These two approaches have never been compared in order to inform their potential for future ITN delivery. We aimed to (1) compare the extent of ITN ownership, use and retreatment coverage in different population groups in the employer and community-based models and (2) identify options for improving people's acceptance and use of treatment/retreatment services. . . .

Distributing insecticide-treated bednets during measles vaccination: a low-cost means of achieving high and equitable coverage — by Kurtis Taylor — last modified 2008-02-12 11:05

In December 2002 in the Lawra district in Ghana, a measles vaccination campaign lasting 1 week targeted all children aged 9 months—15 years. Families with one or more children less than five years old were targeted to receive a free insecticide-treated bednet. The Ghana Health Service, with support from the Ghana Red Cross and UNICEF, provided logistical support, volunteer workers and social mobilization during the campaign. Volunteers visited homes to inform caregivers about the campaign and encourage them to participate. We assessed pre-campaign coverage of bednets by interviewing caregivers leaving vaccination and distribution sites. Five months after distribution, a two-stage cluster survey using population-proportional sampling assessed bednet coverage, retention and use. Both the pre-campaign and post-campaign survey assessed household wealth using an asset inventory. . . .

Distribution of Insecticide-Treated Bednets During a Polio Immunization Campaign --- Niger, 2005 — by Kurtis Taylor — last modified 2008-02-12 11:05

The West African country of Niger (2005 population: approximately 14 million) is among the poorest in the world. In 2005, malaria was reported in approximately 760,000 persons and caused 2,000 deaths; however, surveillance has been inadequate, and the true numbers likely were even higher (1). In 2004, the overall mortality rate in Niger among children aged <5 years was 259 per 1,000 live births (2). At least 8% of these deaths likely were caused by malaria, and the actual proportion might be as high as 50% (3). In addition, Niger was one of only 10 countries with poliomyelitis during the first 3 months of 2006, and the risk for polio importation from neighboring Nigeria is high. Routine polio vaccination coverage remains low in Niger; in 2003, coverage with 3 doses of oral poliovirus vaccine (OPV) was 54% (4,5). To reduce the prevalence of malaria and bolster polio eradication measures, Niger's Ministry of Health, with support from international partners,* launched a nationwide integrated health campaign in 2005. In coordination with a supplemental immunization activity (SIA) distributing OPV, long-lasting insecticide-treated bednets (ITNs)† for malaria prevention were provided free of charge to mothers of children aged <5 years. In sub-Saharan Africa, ITNs have reduced all-cause mortality in children aged 1--59 months by 17% (6). This was the second such national campaign worldwide; the first was conducted in Togo in December 2004 (7). This report describes findings from a survey of Niger's integrated health campaign and highlights differences with the campaign in Togo. . . .

Distribution of Insecticide-Treated Bednets During an Integrated Nationwide Immunization Campaign --- Togo, West Africa, December 2004 — by Kurtis Taylor — last modified 2008-02-12 11:05

During December 13--19, 2004, Togo, a West African nation with a population of approximately 5 million, conducted the first-ever nationwide distribution of insecticide-treated bednets (ITNs) for prevention of malaria. A supplemental immunization activity (SIA), conducted as part of Togo's measles mortality reduction strategy and targeting all children aged 9--59 months, was used as an opportunity to distribute ITNs, oral poliovirus vaccine (OPV), and the anti-helminthic medication, mebendazole. The campaign aimed to achieve >95% coverage among the 866,725 children aged 9--59 months with measles vaccine, OPV, one ITN, and one tablet of mebendazole. This report describes the planning, implementation, and results of this campaign, with emphasis on ITN distribution. The findings demonstrate the feasibility of integrating delivery of these services in a campaign setting. . . .

Efficacy of bifenthrin-impregnated bednets against Anopheles funestus and pyrethroid-resistant Anopheles gambiae in North Cameroon — by Kurtis Taylor — last modified 2008-02-12 11:04

Background Recent field studies indicated that insecticide-treated bednets (ITNs) maintain their efficacy despite a high frequency of the knock-down resistance (kdr) gene in Anopheles gambiae populations. It was essential to evaluate ITNs efficacy in areas with metabolic-based resistance. Bifenthrin was used in this experiment because it is considered a promising candidate for bednets impregnation. Nets were treated at 50 mg/m2, a dose that has high insecticidal activity on kdr mosquitoes and at 5 mg/m2, a dose that kills 95% of susceptible mosquitoes under laboratory conditions with 3 minutes exposure. Bednets were holed to mimic physical damage. The trial was conducted in three experimental huts from Pitoa, North-Cameroon where Anopheles gambiae displays metabolic resistance and cohabits with An. funestus. Bifenthrin at 50 mg/m2 significantly reduced anophelines' entry rate (>80%). This was not observed at 5 mg/m2. Both treatments increased exophily in An. gambiae, and to a lesser extent in An. funestus. With bifenthrin at high dosage, over 60% reduction in blood feeding and 75–90% mortality rates were observed in both vectors. Despite presence of holes, only a single An. gambiae and two An. funestus females were collected inside the treated net, and all were found dead. The same trends were observed with low dosage bifenthrin though in most cases, no significant difference was found with the untreated control net. Bifenthrin-impregnated bednets at 50 mg/m2 were efficient in the reduction of human-vector contact in Pitoa. Considerable personal protection was gained against An. funestus and metabolic pyrethroid resistant An. gambiae populations.

Evaluation of long-lasting insecticidal nets after 2 years of household use — by Kurtis Taylor — last modified 2008-02-12 11:05

Development of long-lasting insecticidal nets (LLINs) may eliminate the need for insecticide retreatment of ITNs. While two LLINs (Olyset®, Sumitomo Chemical Co., Japan; and PermaNet® 1.0, Vestergaard-Frandsen, Denmark) have received recommendations from the World Health Organization Pesticide Evaluation Scheme, field-testing under normal use has been limited. . . .

Evaluations en cases-pièges de l’effet protecteur de moustiquaires non imprégnées d’insecticide dans la prévention des piqûres d’Anopheles gambiae s.s. — by Kurtis Taylor — last modified 2008-02-12 11:05

Une étude sur l’effet protecteur de moustiquaires non imprégnées d’insecticide dans la prévention des piqûres de moustiques a été conduite dans les stations expérimentales de Yaokoffikro et de M’bé en Côte d’Ivoire. Trois conditions ont été testées en cases-pièges : moustiquaires trouées (Yaokoffikro) et moustiquaire intacte ainsi que case dépourvue de moustiquaire (M’bé). Les résultats montrent que, par rapport aux deux autres conditions expérimentales, l’utilisation d’une moustiquaire intacte diminue de 70 % le taux de gorgement d’Anopheles gambiae (24 %), ce qui accentue son exophilie naturelle (38 %). La mortalité relevée avec la moustiquaire intacte (7,4 %) est significativement plus importante que celle enregistrée dans la case sans moustiquaire (5,1 %) mais elle n’est pas significative par rapport aux moustiquaires trouées (4,3 %). . . .

How will the reduction of tariffs and taxes on insecticide- treated bednets affect household purchases? — by Kurtis Taylor — last modified 2008-02-12 11:05

ABSTRACT: One of the steps called for in the fight against malaria is the removal of tariffs and taxes on insecticide-treated bednets (ITNs), netting materials, and insecticides, with a view to reducing the retail prices of ITNs and thus increasing utilization. In this paper we develop an approach for analysing the extent to which reform of tariff and tax policy can be expected to increase ITN purchases. We consider the following questions: (1) How much does the retail price of ITNs change if tariffs and taxes are reduced or eliminated? (2) How responsive is consumer demand to changes in the retail price of ITNs? Data on the price elasticity of demand for ITNs are very limited. Nevertheless, they suggest that ITN demand is not highly responsive to lower prices if household preferences are held constant. The reduction in retail prices associated with the removal of tariffs and taxes depends on the structure of the market in individual countries. In Nigeria, reducing the tariff on insecticides from 42% to zero and the tariff on netting materials from 40% to 5% is expected to increase ITN purchases by 9-27%, depending on the elasticity used. Country-specific information about market structure and cost conditions is needed if predictions are to be made as to how a specific policy change will affect ITN purchases.

Insecticide-Treated Bed Nets — by Kurtis Taylor — last modified 2008-02-12 11:04

Malaria remains one of the world’s most significant health and development problems. More than 2.4 billion of the world’s population residing in 100 countries or territories are at risk of malaria. This results in an estimated 300–500 million clinical cases each year, 90% of which occur in Africa south of the Sahara Desert.1 In these high-burden areas of Africa, Plasmodium falciparum, the most dangerous species of human malaria, causes the great majority of infections. In addition, Anopheles gambiae, the most efficient vector of malaria, predominates throughout large areas of the Africa continent. This combination of a highly dangerous pathogen carried from person to person by a highly competent, resilient vector results in at least one million deaths among young African children each year. Malaria also challenges national authorities with a substantial impediment to economic development, costing the region between $3 billion and 12 billion and inhibiting economic growth by as much as 1.3% each year. The strong relationship between malaria and poverty is perhaps best summarized by the observation that where malaria prospers most, human societies prosper least. . . .

Integrating insecticide-treated bednets into a measles vaccination campaign achieves high, rapid and equitable coverage with direct and voucher-based methods — by Kurtis Taylor — last modified 2008-02-12 11:05

opulation coverage of insecticide-treated nets (ITNs) in Africa falls well below the Abuja target of 60% while coverage levels achieved during vaccination campaigns in the same populations typically exceed 90%. Household (HH) cost of ITNs is an important barrier to their uptake. We investigated the coverage, equity and cost of linking distribution of free ITNs to a measles vaccination campaign. . . .

Long-lasting bednets to be produced in Africa — by Kurtis Taylor — last modified 2008-02-12 11:05

Bulletin of the World Health Organization Print ISSN 0042-9686 Bull World Health Organ vol.81 no.10 Genebra Oct. 2003 WHO, UNICEF and the Acumen Fund jointly announced a potential breakthrough that could save millions of people from malaria every year. For the first time, a Japanese product which extends the life of insecticidal bednets from about one year to more than four years is being manufactured in Africa — where 90 % of the world's malaria deaths occur. . . .

Malaria prevention in highland Kenya: indoor residual house-spraying vs. insecticide-treated bednets — by Kurtis Taylor — last modified 2008-02-12 11:05

This study compares the effectiveness and cost-effectiveness of indoor residual house-spraying (IRS) and insecticide-treated bednets (ITNs) against infection with Plasmodium falciparum as part of malaria control in the highlands of western Kenya. . . .

Malaria prevention in The Gambia: patterns of expenditure and determinants of demand at the household level — by Kurtis Taylor — last modified 2008-02-12 11:05

Objective To provide a better understanding of (1) the amounts households in The Gambia spend on a wide variety of malaria prevention measures, (2) how expenditure fluctuates throughout the year and (3) the main determinants of expenditure. . . .

Perceptions of Bed Nets and Malaria Prevention Before and After a Randomized Controlled Trial of Permethrin - Treated Bed Nets in Western Kenya — by Kurtis Taylor — last modified 2008-02-12 11:04

A study of mothers’ perceptions regarding bed nets and malaria was conducted before and after a randomized controlled trial of insecticide (permethrin)-treated bed nets (ITNs) in western Kenya. Awareness about the trial and the rationale for bed net use increased by the end of the trial. Knowledge that mosquitoes caused malaria also increased; however, a higher proportion of mothers from control, rather than intervention villages, cited this (44.4% versus 27.9%; P < 0.001). Mothers from intervention villages were more knowledgeable about the use and maintenance of bed nets and re-treatment with insecticide. Both groups specified advantages of ITNs. Mothers from intervention villages noted practical advantages such as protection against bedbugs and falling roof debris. Few (< 1%) mothers indicated that ITNs protected children against malaria. Intervention homes used significantly fewer mosquito coils, insect spray, medicines, and burned cow dung less often compared with those in control villages. Mothers were willing to pay approximately U.S. $ 4.5 for a regular bed net, but only U.S. 10.5 cents (intervention) and 0.036 (control) for re-treating a bed net. This study suggests that, despite two years of experience of use, bed nets and insecticides would not be purchased as a household priority in this impoverished rural community.

Social marketing of insecticide-treated bednets — by Kurtis Taylor — last modified 2008-02-12 11:05

Social marketing is the practice of applying marketing principles to products and services with a societal benefit. Abdulla et al.[1] report on the results of the Kilombero Net project (KINET), a social marketing programme for the ‘Zuia Mbu’ (‘prevent mosquitoes’) brand of insecticide-treated bednets (ITBNs) in the Kilombero and Ulanga districts of south-western Tanzania.

Successful Integration of Insecticide-Treated Bed Net Distribution with Mass Drug Administration in Central Nigeria — by Kurtis Taylor — last modified 2008-02-12 11:04

In Africa anopheline mosquitoes transmit malaria and lymphatic filariasis (LF); insecticide-treated bed nets significantly reduce transmission of both. Insecticide-treated bed net provision to children under 5 (U5) and pregnant women (PW) is a major goal of malaria control initiatives, but use in Africa remains low because of cost and logistics. We therefore integrated insecticide-treated bed net distribution with the 2004 LF/onchocerciasis mass drug administration (MDA) program in Central Nigeria. Community volunteers distributed 38,600 insecticide-treated bed nets, while simultaneously treating 150,800 persons with ivermectin/albendazole (compared with 135,600 in 2003). This was subsequently assessed with a 30-cluster survey. Among surveyed households containing U5/PW, 80% (95% CI, 72–87%) owned ≥ 1 insecticide-treated bed net, a 9-fold increase from 2003. This first linkage of insecticide-treated bed net distribution with mass drug administration resulted in substantial improvement in insecticide-treated bed net ownership and usage, without adversely affecting mass drug administration coverage. Such integration allowed two programs to share resources while realizing mutual benefit, and is one model for rapidly improving insecticide-treated bed net coverage objectives.

The cost of not treating bednets — by Kurtis Taylor — last modified 2008-02-12 11:05

The evidence for a protective effect of untreated nets against malaria is presented here alongside an analysis of how well untreated nets would need to work in order to compete with treated nets within a cost-effectiveness framework.