Insecticide-treated Mosquito Nets Coverage Research Articles

Malaria reduction drives childhood stunting decline in Uganda: a mixed-methods country case study

ABSTRACTBackgroundUganda has achieved a considerable reduction in childhood stunting over the past 2 decades, although accelerated action will be needed to achieve 2030 targets.ObjectivesThis study assessed the national, community, household, and individual-level drivers of stunting decline since 2000, along with direct and indirect nutrition policies and programs that have contributed to nutrition change in Uganda.MethodsThis mixed-methods study used 4 different approaches to determine the drivers of stunting change over time: 1) a scoping literature review; 2) quantitative data analyses, including Oaxaca–Blinder decomposition and difference-in-difference multivariable hierarchical modeling; 3) national- and community-level qualitative data collection and analysis; and 4) analysis of key direct and indirect nutrition policies, programs, and initiatives.ResultsStunting prevalence declined by 14% points from 2000 to 2016, although geographical, wealth, urban/rural, and education-based inequalities persist. Child growth curves demonstrated substantial improvements in child height-for-age z-scores (HAZs) at birth, reflecting improved maternal nutrition and intrauterine growth. The decomposition analysis explained 82% of HAZ change, with increased coverage of insecticide-treated mosquito nets (ITNs; 35%), better maternal nutrition (19%), improved maternal education (14%), and improved maternal and newborn healthcare (11%) being the most critical factors. The qualitative analysis supported these findings, and also pointed to wealth, women's empowerment, cultural norms, water and sanitation, dietary intake/diversity, and reduced childhood illness as important. The 2011 Uganda Nutrition Action Plan was an essential multisectoral strategy that shifted nutrition out of health and mainstreamed it across related sectors.ConclusionsUganda's success in stunting reduction was multifactorial, but driven largely through indirect nutrition strategies delivered outside of health. To further improve stunting, it will be critical to prioritize malaria-control strategies, including ITN distribution campaigns and prevention/treatment approaches for mothers and children, and deliberately target the poor, least educated, and rural populations along with high-burden districts.

Malaria Reduction Drove Childhood Stunting Decline in Uganda: A Mixed-Methods Country Case Study

Background: Uganda has achieved a considerable reduction in childhood stunting over the past two decades, though accelerated action will be needed to achieve 2030 targets. This study assessed the national, community, household, and individual-level drivers of stunting decline since 2000, along with direct and indirect nutrition policies and programs that have contributed to nutrition change in Uganda. Methods: This mixed-methods study used 4 different approaches to determine the drivers of stunting change over time: 1) a systematic literature review; 2) quantitative data analyses, including Oaxaca-Blinder decomposition and difference-in-difference multivariable hierarchical modeling; 3) national and community-level qualitative data collection and analysis; and 4) analysis of key direct and indirect nutrition policies, programs, and initiatives. Findings: Stunting prevalence declined by 14% points from 2000 to 2016, though geographical, wealth, urban/rural, and education-based inequalities persist. Child growth curves demonstrated substantial improvements in child height-for-age z-scores (HAZ) at birth, reflecting improved maternal nutrition and intrauterine growth. The decomposition analysis explained 82% of HAZ change, with increased coverage of insecticide-treated mosquito nets (ITNs; 35%), better maternal nutrition (19%), improved maternal education (14%), and improved maternal and newborn healthcare (11%) being the most critical factors. The qualitative analysis supported these findings, and also pointed to wealth, women’s empowerment, cultural norms, water and sanitation, dietary intake, and childhood illness as important. The 2011 Uganda Nutrition Action Plan was an essential multi-sectoral strategy that shifted nutrition out of health and mainstreamed it across related sectors. Interpretation: Uganda’s success in stunting reduction was multi-factorial, but driven largely through indirect nutrition strategies delivered outside of health. To further improve stunting, it will be critical to prioritize malaria-control strategies, including ITN distribution campaigns and prevention/treatment approaches for mothers and children, and deliberately target the poor, least educated and rural populations along with high-burden northern and western districts. Funding: This study was funded by the Bill & Melinda Gates Foundation and Gates Ventures. Declaration of Interest: None to declare. Ethical Approval: Ethics approval was obtained from the Makerere University School of Public Health Higher Degrees Research Ethical Committee (Uganda), the Uganda National Council of Science and Technology, and the Research Ethics Board at the Hospital for Sick Children (Canada).

Malaria prevention practices and associated environmental risk factors in a rural community in Wakiso district, Uganda.

BackgroundBesides use of insecticide-treated mosquito nets (ITNs) and indoor residual spraying (IRS), other complimentary measures including suitable housing structures, and environmental management that reduce breeding of malaria vectors, can be implemented at households to prevent the disease. However, most studies on malaria prevention have focused mainly on ITNs and IRS. The aim of this study was therefore to assess malaria prevention practices beyond ITNs and IRS, and associated environmental risk factors including housing structure in rural Wakiso district, Uganda.MethodsA clustered cross-sectional survey was conducted among 727 households in Wakiso district. Data were collected using an interviewer-administered questionnaire and observational checklist. The questionnaire assessed participants’ household practices on malaria prevention, whereas the checklist recorded environmental risk factors for malaria transmission, and structural condition of houses. Poisson regression modeling was used to identify factors associated with use of mosquito nets by households.ResultsOf the 727 households, 471 (64.8%) owned at least one mosquito net. Use of mosquito nets by households was higher with increasing education level of participants—primary (aPR = 1.27 [95% CI: 1.00–1.60]), secondary (ordinary level) (aPR = 1.47 [95% CI: 1.16–1.85]) and advanced level / tertiary (aPR = 1.55 [95% CI: 1.19–2.01]), and higher household income (aPR = 1.09 [95% CI: 1.00–1.20]). Additionally, participants who were not employed were less likely to have mosquito nets used in their households (aPR = 0.83 [95% CI: 0.70–0.98]). Houses that had undergone IRS in the previous 12 months were 42 (5.8%), while 220 (43.2%) households closed their windows before 6.00 pm. Environmental risk factors found at households included presence of vessels that could potentially hold water for mosquito breeding 414 (56.9%), and stagnant water in compounds 144 (19.8%). Several structural deficiencies on houses that could promote entry of mosquitoes were found such as lack of screening in ventilators 645 (94.7%), and external doors not fitting perfectly into walls hence potential for mosquito entry 305 (42.0%).ConclusionThere is need to increase coverage and utilisation of ITNs and IRS for malaria prevention in Wakiso district, Uganda. In addition, other malaria prevention strategies such as environmental management, and improving structural condition of houses are required to strengthen existing malaria prevention approaches.

Impact of malaria interventions on child mortality in endemic African settings: comparison and alignment between LiST and Spectrum-Malaria model

BackgroundIn malaria-endemic countries, malaria prevention and treatment are critical for child health. In the context of intervention scale-up and rapid changes in endemicity, projections of intervention impact and optimized program scale-up strategies need to take into account the consequent dynamics of transmission and immunity.MethodsThe new Spectrum-Malaria program planning tool was used to project health impacts of Insecticide-Treated mosquito Nets (ITNs) and effective management of uncomplicated malaria cases (CMU), among other interventions, on malaria infection prevalence, case incidence and mortality in children 0–4 years, 5–14 years of age and adults. Spectrum-Malaria uses statistical models fitted to simulations of the dynamic effects of increasing intervention coverage on these burdens as a function of baseline malaria endemicity, seasonality in transmission and malaria intervention coverage levels (estimated for years 2000 to 2015 by the World Health Organization and Malaria Atlas Project). Spectrum-Malaria projections of proportional reductions in under-five malaria mortality were compared with those of the Lives Saved Tool (LiST) for the Democratic Republic of the Congo and Zambia, for given (standardized) scenarios of ITN and/or CMU scale-up over 2016–2030.ResultsProportional mortality reductions over the first two years following scale-up of ITNs from near-zero baselines to moderately higher coverages align well between LiST and Spectrum-Malaria —as expected since both models were fitted to cluster-randomized ITN trials in moderate-to-high-endemic settings with 2-year durations. For further scale-up from moderately high ITN coverage to near-universal coverage (as currently relevant for strategic planning for many countries), Spectrum-Malaria predicts smaller additional ITN impacts than LiST, reflecting progressive saturation. For CMU, especially in the longer term (over 2022–2030) and for lower-endemic settings (like Zambia), Spectrum-Malaria projects larger proportional impacts, reflecting onward dynamic effects not fully captured by LiST.ConclusionsSpectrum-Malaria complements LiST by extending the scope of malaria interventions, program packages and health outcomes that can be evaluated for policy making and strategic planning within and beyond the perspective of child survival.

Significant decline in lymphatic filariasis associated with nationwide scale-up of insecticide-treated nets in Zambia

Lymphatic filariasis (LF) is a mosquito-borne disease, broadly endemic in Zambia, and is targeted for elimination by mass drug administration (MDA) of albendazole and diethylcarbamazine citrate (DEC) to at-risk populations. Anopheline mosquitoes are primary vectors of LF in Africa, and it is possible that the significant scale-up of malaria vector control over the past decade may have also impacted LF transmission, and contributed to a decrease in prevalence in Zambia. We therefore aimed to examine the putative association between decreasing LF prevalence and increasing coverage of insecticide-treated mosquito nets (ITNs) for malaria vector control, by comparing LF mapping data collected between 2003–2005 and 2009–2011 to LF sentinel site prevalence data collected between 2012 and 2014, before any anti-LF MDA was started. The coverage of ITNs for malaria was quantified and compared for each site in relation to the dynamics of LF. We found a significant decrease in LF prevalence from the years 2003–2005 (11.5% CI95 6.6; 16.4) to 2012–2014 (0.6% CI95 0.03; 1.1); at the same time, there was a significant scale-up of ITNs across the country from 0.2% (CI95 0.0; 0.3) to 76.1% (CI95 71.4; 80.7) respectively. The creation and comparison of two linear models demonstrated that the geographical and temporal variation in ITN coverage was a better predictor of LF prevalence than year alone. Whilst a causal relationship between LF prevalence and ITN coverage cannot be proved, we propose that the scale-up of ITNs has helped to control Anopheles mosquito populations, which have in turn impacted on LF transmission significantly before the scale-up of MDA. This putative synergy with vector control has helped to put Zambia on track to meet national and global goals of LF elimination by 2020.

Assessment of coverage of preventive treatment and insecticide-treated mosquito nets in pregnant women attending antenatal care services in 11 districts in Mozambique in 2011: the critical role of supply chain

BackgroundMalaria during pregnancy is associated with poor maternal and pregnancy outcome and the World Health Organization recommends the administration of intermittent preventive treatment in pregnancy (IPTp) with sulfadoxine-pyrimethamine (SP) and distribution of insecticide-treated mosquito nets (ITNs) to all pregnant women attending antenatal care (ANC) services. This study was conducted with the aim to assess the uptake of IPTp and ITNs in pregnant women attending ANC services and correlate with ANC attendance and frequency of stock-outs in 22 health facilities Mozambique.MethodsA cross-sectional study was conducted between July and December 2011 in 22 health units in 11 districts situated in 11 provinces in Mozambique. Two health facilities were selected per district (one urban and one rural). Data were collected by reviewing logbooks of antenatal consultations as well as from monthly district reports.ResultsDuring the period under investigation, a total of 23,524 pregnant women attended their 1st antenatal care visits, of which 12,775 (54.3%) and 7581 (32.2%) received one and two doses of IPTp, respectively. In regard to ITNs, a total of 16,436 (69.9%) pregnant women received ITNs. Uptake of IPTp and ITNs by pregnant women at ANC services was higher in southern Mozambique and lower in districts situated in the northern part of the country. Stock-outs of SP and ITNs were reported in 50.0% (11/22) and 54.5% (12/22) of the health facilities, respectively. Coverage of IPTp and ITN in health facilities with stock-outs of SP and ITNs was much lower as compared to health facilities with no stock-outs.ConclusionsAltogether, data from this study shows that coverage of the 2nd dose of IPTp, as well as ITNs, was low in pregnant women attending ANC services in Mozambique. In addition, this data also shows that stock-outs of SP and ITNs were frequent and led to lower coverage of IPTp and ITN, representing a serious barrier for the accomplishment of targets. In conclusion, this study recommends that efforts should be made to improve the supply chains of SP and ITNs.

Malaria incidence during early childhood in rural Burkina Faso: Analysis of a birth cohort protected with insecticide-treated mosquito nets

BackgroundEven in the high transmission areas of sub-Saharan Africa (SSA), the incidence of falciparum malaria varies greatly depending on factors such as age, rainfall pattern, distance to breeding places, quality of houses, and existing vector control measures. Insecticide-treated mosquito nets (ITN) have now become the vector control standard in nearly all of SSA. This study aims to describe and analyse the incidence of malaria in a cohort of young children protected with ITN in rural West Africa. MethodsData of a subsample from a large community trial in rural north-western Burkina Faso consisting of 420 children were analysed. The main aim of the trial was to evaluate the long-term effects of ITNs in two groups of new-borns; Group A was protected with ITN from birth onwards while Group B was protected only from month six onwards. The primary objective of this study was to describe malaria incidence in detail with an analysis of the impact of potentially relevant determinants of malaria incidence, in particular age, sex, ITN protection, village, month and season as secondary objective. Bivariate negative binomial regression analysis was used to calculate incidence rate ratios of malaria incidence. Moreover, relevant variables were included in a multivariate negative binomial regression model to examine possible risk factors for malaria. ResultsOut of the 420 study children 387 (92.1%) developed a total of 1822 falciparum malaria episodes; the malaria incidence rate was 7.6 per 1000 child days. Group A children had lower malaria incidence rates compared to group B, but only in early infancy. Malaria incidence varied significantly between villages and increased with age, but no sex-specific differences were observed; these findings were confirmed in the multi-variate analysis. Malaria incidence peaked sharply towards the end of the rainy season in September but there were no differences in the seasonal pattern by study group. ConclusionsThe study, carried out in a high-transmission West African area, shows that malaria incidence remains high in spite of maximum ITN coverage.

Community coverage with insecticide-treated mosquito nets and observed associations with all-cause child mortality and malaria parasite infections.

Randomized trials and mathematical modeling suggest that insecticide-treated mosquito nets (ITNs) provide community-level protection to both those using ITNs and those without individual access. Using nationally representative household survey datasets from 17 African countries, we examined whether community ITN coverage is associated with malaria infections in children < 5 years old and all-cause child mortality (ACCM) among children < 5 years old in households with one or more ITNs versus without any type of mosquito net (treated or untreated). Increasing ITN coverage (> 50%) was protective against malaria infections and ACCM for children in households with an ITN, although this protection was not conferred to children in households without ITNs in these data. Children in households with ITNs were protected against malaria infections and ACCM with ITN coverage > 30%, but this protection was not significant with ITN coverage < 30%. Results suggest that ITNs are more effective with higher ITN coverage.

Insecticide-treated mosquito nets in rural Burkina Faso: assessment of coverage and equity in the wake of a universal distribution campaign

Insecticide-treated mosquito nets (ITNs) are an essential tool of the Roll Back Malaria strategy. An increasing number of African countries have embarked on mass distribution campaigns of long-lasting insecticide-treated nets (LLINs) with the ultimate goal of universal coverage. Such a national campaign with the goal of one ITN for every two people has been conducted in Burkina Faso in 2010. Our aim was to assess the coverage and equity effect of the universal distribution campaign of LLINs in Burkina Faso and to identify determinants of ITN ownership across households after the campaign. We evaluated its effects through comparison of data from two household surveys conducted in early 2010 (before the campaign) and early 2011 (after the campaign) on a representative rural district in north-western Burkina Faso. Data were collected on household characteristics (including socio-economic status) and ITN ownership. We used concentration curves and indices to compare ITN coverage indicators before and after the campaign and multilevel multivariate logistic regression to estimate factors associated with achievement of the universal coverage target in 2011. The survey included 1106 households in 2010 and 1094 in 2011. We found that the proportion of households with at least one ITN increased from 59% before the campaign to 99% afterwards, whereas the concentration index dropped from 0.087 (standard error (SE): 0.014) to 0.002 (SE: 0.002). Fifty-two per cent of households reached the target of one ITN for every two people per household, with the relevant concentration index at -0.031 (SE: 0.016). Eighty-six per cent of households owned at least one ITN for every three people. The main characteristics significantly associated with the targeted intra-household coverage were family size and distance to the health centre but not socio-economic status. In conclusion, despite not having fully met its target, the national LLIN campaign achieved a high level of coverage and fostered equity.

Is there preferential coverage for the most at risk? A survey-based analysis of malaria vector control by endemicity level

BackgroundAlthough US$2·3 billion in 2011 was spent on malaria control globally, a financing gap of $2·8 billion remains. While equity in intervention coverage is the ultimate goal, with limited resources, it is crucial to target interventions strategically. Developments in cartographic methods for estimating Plasmodium falciparum parasite rate (PfPR) at low geospatial levels and availability of household surveys with global positioning system (GPS) coordinates now allow for estimation of malaria intervention coverage stratified by level of infection risk. Taking advantage of this information, we aim to identify whether malaria interventions are targeted to those populations most at risk of malaria infection. MethodsOur study spanned 24 countries and used all 38 Malaria Indicator Surveys and Demographic and Health Surveys with GPS coordinates and survey questions on use of insecticide-treated mosquito nets (ITNs). For these surveys, conducted between 2003 and 2011, we obtained cluster-level PfPR by matching coordinates of surveyed clusters to coordinates from Malaria Atlas Project PfPR maps. For each survey, we calculated the proportion of household availability of ITNs and prevalence of indoor residual spraying (IRS) by level of malaria endemicity (low, intermediate, high). We sought to further explain variation in coverage of vector control interventions by examining PfPR by wealth quintile and urban or rural residence. FindingsCoverage of ITNs or IRS by endemicity level varies greatly by country and year. In only four (Burundi, Ethiopia, Senegal, Zimbabwe) of the 24 surveyed countries did the coverage of IRS or availability of ITNs increase monotonically with increasing endemicity level. While coverage of ITNs or IRS in Senegal in 2010 among populations at low risk was 16·4% (95% CI 13·2–19·6), coverage among those at intermediate and high risk was 31·7% (27·8–35·5) and 64·6% (30·0–99·0), respectively. By contrast, coverage in Tanzania in the same year was 73·5% (95% CI 69·3–77·6) among those at lowest risk, and 67·5% (64·4–70·7) and 53·0 (48·2–57·8) among those at medium and high risk, respectively. Nearly all surveys indicate lower coverage of vector control interventions and higher PfPR in poorer, more rural areas. InterpretationIn the countries examined in this study, coverage of vector control interventions did not necessarily increase with increasing malaria risk. If limited resources preclude protecting all persons at risk of malaria with vector control interventions, strategies for targeting interventions (such as on the basis of malaria risk) should be devised to achieve their greatest lifesaving potential. FundingNone.

Progress towards malaria control targets in relation to national malaria programme funding

BackgroundMalaria control has been dramatically scaled up the past decade, mainly thanks to increasing international donor financing since 2003. This study assessed progress up to 2010 towards global malaria impact targets, in relation to Global Fund, other donor and domestic malaria programme financing over 2003 to 2009.MethodsAssessments used domestic malaria financing reported by national programmes, and Global Fund/OECD data on donor financing for 90 endemic low- and middle-income countries, WHO estimates of households owning one or more insecticide-treated mosquito net (ITN) for countries in sub-Saharan Africa, and WHO-estimated malaria case incidence and deaths in countries outside sub-Saharan Africa.ResultsGlobal Fund and other donor funding is concentrated in a subset of the highest endemic African countries. Outside Africa, donor funding is concentrated in those countries with highest malaria mortality and case incidence rates over the years 2000 to 2003. ITN coverage in 2010 in Africa, and declines in case and death rates per person at risk over 2004 to 2010 outside Africa, were greatest in countries with highest donor funding per person at risk, and smallest in countries with lowest donor malaria funding per person at risk. Outside Africa, all-source malaria programme funding over 2003 to 2009 per case averted ($56-5,749) or per death averted ($58,000-3,900,000) over 2004 to 2010 tended to be lower (more favourable) in countries with higher donor malaria funding per person at risk.ConclusionsIncreases in malaria programme funding are associated with accelerated progress towards malaria control targets. Associations between programme funding per person at risk and ITN coverage increases and declines in case and death rates suggest opportunities to maximize the impact of donor funding, by strategic re-allocation to countries with highest continued need.

Moving towards universal coverage with malaria control interventions: achievements and challenges in rural Burkina Faso

This paper reports on a study, which assessed coverage with malaria control interventions in rural Burkina Faso, namely insecticide-treated mosquito nets (ITN) ownership, intermittent preventive treatment (IPTp) for pregnant women and artemisinin-based combination therapy (ACT) for under-five children. The study also addressed the distributional impact of such interventions, with specific reference to equity. The study used data from a representative household survey conducted on 1106 households in the Nouna Health District in 2010. Findings indicated that 59% of all households owned at least one ITN, 66% of all pregnant women received IPT at least once and 34% of under-five children reporting a malaria case were treated with ACT. Multivariate logistic regression revealed that higher socio-economic status, ownership of at least one radio and living in a village within a Health and Demographic Surveillance System were significantly positively associated with ITN, IPTp and ACT coverage. ITN coverage was higher among households in villages, which had previously hosted an ITN trial and/or the most favourable arm of a trial. Comparing current findings with previous estimates suggests that the country has made substantial progress towards scaling up malaria control interventions but that current coverage rates are still far from achieving the universal coverage targets set by the Roll Back Malaria Partnership. In addition, current coverage patterns reveal the existence of multiple inequities across groups, suggesting that current policies are inadequate to achieve equitable scaling up. Future planning of malaria control interventions ought to take into consideration current inadequacies and lead to programmes better designed to overcome them.

Long‐term effects of malaria prevention with insecticide‐treated mosquito nets on morbidity and mortality in African children: randomised controlled trial

The objective is to investigate the effect of malaria control with insecticide-treated mosquito nets (ITNs) regarding possible higher mortality in children protected during early infancy, due to interference with immunity development, and to assess long-term effects on malaria prevalence and morbidity. Between 2000 and 2002, a birth cohort was enrolled in 41 villages of a malaria holoendemic area in north-western Burkina Faso. All neonates (n = 3387) were individually randomised to ITN protection from birth (group A) vs. ITN protection from age 6 months (group B). Primary outcome was all-cause mortality. In 2009, a survey took place in six sentinel villages, and in 2010, a census was conducted in all study villages. After a median follow-up time of 8.3 years, 443/3387 (13.1%) children had migrated out of the area and 484/2944 (16.4%) had died, mostly at home. Long-term compliance with ITN protection was good. There were no differences in mortality between study groups (248 deaths in group A, 236 deaths in group B; rate ratio 1.05, 95% CI: 0.889-1.237, P = 0.574). The survey conducted briefly after the rainy season in 2009 showed that more than 80% of study children carried asexual malaria parasites and up to 20% had clinical malaria. Insecticide-treated mosquito net protection in early infancy is not a risk factor for mortality. Individual ITN protection does not sufficiently reduce malaria prevalence in high-transmission areas. Achieving universal ITN coverage remains a major challenge for malaria prevention in Africa.

Factors Influencing the Usage of Insecticide Treated Mosquito Nets among Pregnant Women

Purpose: Malaria in Sudan is a leading cause of morbidity and mortality. Incidence remains very high especially among pregnant women and children under five. study was conducted to determine the factors influencing the usage of insecticide treated mosquito nets (ITNs) for prevention of malaria among pregnant women. Methods: A cross-sectional study design with convenience nts, prevalence of malaria was 71.2%. The coverage of ITNs was 58.7% but only 11.5% used ITNs regularly. Ninety six (92.3%) showed good knowledge on malaria causes, 103 (99%) had good knowledge on malaria complications and 62 (59.6%) showed good knowledge on the aim of ITNs usage. Only 23 (22.1%) knew the proper usage of ITNs. Maternal age, income, gravidity, parity, abortion, number of family members, usage of ITNs during last pregnancy, previous history of malaria, usage of ITNs by other family members and accessibility to ITNs were significantly associated with current usage of ITNs. Conclusion: Although there was good knowledge of ITNs among women in Sudan, proper usage of ITNs is poor. Factors influencing usage of ITNs among the pregnant women include maternal age, income, gravidity, parity, abortion, number of family members, usage of ITNs during last pregnancy, previous history of malaria, usage of ITNs by other family members and accessibility to ITNs. Keywords: ITN, malaria, pregnancy, Sudan.

Net Benefits: A Multicountry Analysis of Observational Data Examining Associations between Insecticide-Treated Mosquito Nets and Health Outcomes

Several sub-Saharan African countries have rapidly scaled up the number of households that own insecticide-treated mosquito nets (ITNs). Although the efficacy of ITNs in trials has been shown, evidence on their impact under routine conditions is limited to a few countries and the extent to which the scale-up of ITNs has improved population health remains uncertain. We used matched logistic regression to assess the individual-level association between household ITN ownership or use in children under 5 years of age and the prevalence of parasitemia among children using six malaria indicator surveys (MIS) and one demographic and health survey. We used Cox proportional hazards models to assess the relationship between ITN household ownership and child mortality using 29 demographic and health surveys. The pooled relative reduction in parasitemia prevalence from random effects meta-analysis associated with household ownership of at least one ITN was 20% (95% confidence interval [CI] 3%-35%; I² = 73.5%, p<0.01 for I² value). Sleeping under an ITN was associated with a pooled relative reduction in parasitemia prevalence in children of 24% (95% CI 1%-42%; I² = 79.5%, p<0.001 for I² value). Ownership of at least one ITN was associated with a pooled relative reduction in mortality between 1 month and 5 years of age of 23% (95% CI 13-31%; I² = 25.6%, p>0.05 for I² value). Our findings across a number of sub-Saharan African countries were highly consistent with results from previous clinical trials. These findings suggest that the recent scale-up in ITN coverage has likely been accompanied by significant reductions in child mortality and that additional health gains could be achieved with further increases in ITN coverage in populations at risk of malaria. Please see later in the article for the Editors' Summary.

Price subsidies and the market for mosquito nets in developing countries: A study of Tanzania’s discount voucher scheme

This study uses a partial equilibrium simulation model to explore how price subsidies for insecticide-treated mosquito nets (ITNs) affect households’ purchases of ITNs. The model describes the ITN market in a typical developing country and is applied to the situation in Tanzania, where the Tanzania National Voucher Scheme (TNVS) provides a targeted subsidy to vulnerable population groups by means of a discount voucher. The data for this study come from a nationally-representative household survey completed July–August 2006 covering over 4300 households in 21 districts. The simulation results show the impact of the voucher program on ITN coverage among target households, namely those that experienced the birth of a child. More specifically, the share of target households purchasing an ITN increased from 18 to 62 percent because of the discount voucher. The model also suggests that the voucher program could cause the retail ITN price to rise due to an overall increase in demand. As a result, ITN purchases by households without a voucher may actually decline. The simulation model suggests that additional increases toward the stated goal of 80 percent ITN coverage for pregnant women and children could best be achieved through a combination of “catch up” mass distribution programs and expanding the target group for the voucher program to cover additional households. The model can be employed in other countries considering use of a targeted price subsidy for ITNs, and could be adapted to assess the impact of subsidies for other public health commodities.

Malaria Infection and Anemia Prevalence in Zambia's Luangwa District: An Area of Near-Universal Insecticide-Treated Mosquito Net Coverage

We examined the relationship between insecticide-treated mosquito nets (ITNs), malaria parasite infection, and severe anemia prevalence in children in Luangwa District, Zambia, an area with near-universal ITN coverage, at the end of the 2008 and 2010 malaria transmission seasons. Malaria parasite infection prevalence among children < 5 years old was 9.7% (95% confidence interval [CI] = 8.0–11.4%) over both survey years. Prevalence of severe anemia among children 6–59 months old was 6.9% (95% CI = 5.4–8.5%) over both survey years. Within this context of near-universal ITN coverage, we were unable to detect a significant association between malaria parasite or severe anemia prevalence and ITNs (possession and use). In addition to maintaining universal ITN coverage, it will be essential for the malaria control program to achieve high ITN use and laboratory diagnosis and treatment of all fevers among all age groups to further reduce the malaria burden in this area.

Barriers to Insecticide-Treated Mosquito Net Possession 2 Years after a Mass Free Distribution Campaign in Luangwa District, Zambia

Background and MethodsRoll Back Malaria set the goal of 100% of households in malaria endemic countries in Africa owning an insecticide-treated mosquito net (ITN) by 2010. Zambia has used mass free distribution campaigns and distribution through antenatal care (ANC) clinics to achieve high coverage.Methodology and Principal FindingsWe conducted a probability survey of 801 households in 2008 to assess factors associated with households that lacked an ITN after mass distribution. Community perceptions of barriers to ITN access were also obtained from in-depth interviews with household heads that reported not owning an ITN. Nearly 74% of households in Luangwa district reported owning ≥1 ITN. Logistic regression showed households without a child <5 years old during the ITN distribution campaigns were twice as likely to not have an ITN as those with a child <5 during distribution (Adjusted odds ratio (AOR) = 2.43; 95% confidence interval (CI): 1.67–3.55). Households without a woman who attended an ANC in the past 2 years were more likely to be without ITNs compared to households with a woman who attended an ANC in the past 2 years (AOR = 1.52; 95% CI: 1.04–2.21). In-depth interviews with heads of households without an ITN revealed that old age was a perceived barrier to receiving an ITN during distribution, and that ITNs wore out before they could be replaced.Conclusions and SignificanceDelivery of a large number of ITNs does not translate directly into 100% household coverage. Due to their design, current ITN distribution strategies may miss households occupied by the elderly and those without children or ANC access. ITN distribution strategies targeting the elderly, those with limited access to distribution points, and others most likely to be missed are necessary if 100% ITN coverage of households is to be achieved.

Malaria control under the Taliban regime: insecticide-treated net purchasing, coverage, and usage among men and women in eastern Afghanistan

BackgroundScaling up insecticide-treated mosquito net (ITN) coverage is a key malaria control strategy even in conflict-affected countries [1,2]. Socio-economic factors influence access to ITNs whether subsidized or provided free to users. This study examines reported ITN purchasing, coverage, and usage in eastern Afghanistan and explores women's access to health information during the Taliban regime (1996-2001). This strengthens the knowledge base on household-level health choices in complex-emergency settings.MethodsFifteen focus group discussions (FGDs) and thirty in-depth interviews were conducted with men and women from ITN-owning and non-owning households. FGDs included rank ordering, pile sorting and focused discussion of malaria knowledge and ITN purchasing. Interviews explored general health issues, prevention and treatment practices, and women's malaria knowledge and concerns. Seven key informant interviews with health-related workers and a concurrent survey of 200 ITN-owning and 214 non-owning households were used to clarify or quantify findings.ResultsMalaria knowledge was similar among men and women and ITN owners and non-owners. Women reported obtaining health information through a variety of sources including clinic staff, their husbands who had easier access to information, and particularly female peers. Most participants considered ITNs very desirable, though not usually household necessities. ITN owners reported more household assets than non-owners. Male ITN owners and non-owners ranked rugs and ITNs as most desired, while women ranked personal assets such as jewellery highest. While men were primarily responsible for household decision-making and purchasing, older women exerted considerable influence. Widow-led and landless households reported most difficulties purchasing ITNs. Most participants wanted to buy ITNs only if they could cover all household members. When not possible, preferential usage was given to women and children.ConclusionsDespite restricted access to health facilities and formal education, Afghan women were surprisingly knowledgeable about the causes of malaria and the value of ITNs in prevention. Inequities in ITN usage were noted between rather than within households, with some unable to afford even one ITN and others not wanting ITNs unless all household members could be protected. Malaria knowledge thus appears a lesser barrier to ITN purchasing and coverage in eastern Afghanistan than are pricing and distribution strategies.