Insecticide-Treated Nets for the Prevention of Malaria in Pregnancy: A Systematic Review of Randomised Controlled Trials

University of Liverpool, Liverpool, England, United Kingdom
PLoS Medicine (Impact Factor: 14.43). 04/2007; 4(3):e107. DOI: 10.1371/journal.pmed.0040107
Source: PubMed


Protection from malaria with insecticide-treated bednets (ITNs) during pregnancy is widely advocated, but evidence of benefit has been inconsistent. We undertook a systematic review of randomised trials.
Three cluster-randomised and two individually randomised trials met the inclusion criteria; four from Africa (n = 6,418) and one from Thailand (n = 223). In Africa, ITNs compared to no nets increased mean birth weight by 55 g (95% confidence interval [CI] 21-88), reduced low birth weight by 23% (relative risk [RR] 0.77, 95% CI 0.61-0.98), and reduced miscarriages/stillbirths by 33% (RR 0.67, 0.47-0.97) in the first few pregnancies. Placental parasitaemia was reduced by 23% in all gravidae (RR 0.77, 0.66-0.90). The effects were apparent in the cluster-randomised trials and the one individually randomised trial in Africa. The trial in Thailand, which randomised individuals to ITNs or untreated nets, showed reductions in anaemia and fetal loss in all gravidae, but not reductions in clinical malaria or low birth weight.
ITNs used throughout pregnancy or from mid-pregnancy onwards have a beneficial impact on pregnancy outcome in malaria-endemic Africa in the first few pregnancies. The potential impact of ITNs in pregnant women and their newborns in malaria regions outside Africa requires further research.

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    • "alth issue in Tanzania that needs to be addressed by effective preventive measures . Self - reporting of ITNs use by 95% of pregnant women is encouraging considering the reported ITNs efficacy of 23% against placental parasitaemia , 33% against miscar - riage / stillbirth and 23% against LBW according to a systematic reviews of randomised trials ( Gamble et al . 2007 ) . The possibility of overestimating ITNs use in the present study cannot be excluded due to self - reporting as the participant may try to please the interviewer . In the present study , all women with placental malaria reported to have used ITNs , which precludes any effectiveness cal - culation . Our assessment of IPTp effectiveness"
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    ABSTRACT: Objective: To assess the effectiveness of IPTp in two areas with different malaria transmission intensities. Methods: Prospective observational study recruiting pregnant women in two health facilities in areas with high and low malaria transmission intensities. A structured questionnaire was used for interview. Maternal clinic cards and medical logs were assessed to determine drug intake. Placental parasitaemia was screened using both light microscopy and real-time quantitative PCR. Results: Of 350 pregnant women were recruited and screened for placental parasitaemia, 175 from each area. Prevalence of placental parasitaemia was 16.6% (CI 11.4-22.9) in the high transmission area and 2.3% (CI 0.6-5.7) in the low transmission area. Being primigravida and residing in a high transmission area were significant risk factors for placental malaria (OR 2.4; CI 1.1-5.0; P = 0.025) and (OR 9.4; CI 3.2-27.7; P < 0.001), respectively. IPTp was associated with a lower risk of placental malaria (OR 0.3; CI 0.1-1.0; P = 0.044); the effect was more pronounced in the high transmission area (OR 0.2; CI 0.06-0.7; P = 0.015) than in the low transmission area (OR 0.4; CI 0.04-4.5; P = 0.478). IPTp use was not associated with reduced risk of maternal anaemia or low birthweight, regardless of transmission intensity. The number needed to treat (NNT) was four (CI 2-6) women in the high transmission area and 33 (20-50) in the low transmission area to prevent one case of placental malaria. Conclusion: IPTp may have an effect on lowering the risk of placental malaria in areas of high transmission, but this effect did not translate into a benefit on risks of maternal anaemia or low birthweight. The NNT needs to be considered, and weighted against that of other protective measures, eventually targeting areas which are above a certain threshold of malaria transmission to maximise the benefit.
    Tropical Medicine & International Health 06/2014; 19(9). DOI:10.1111/tmi.12349 · 2.33 Impact Factor
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    • "Long-lasting, insecticide-treated bed nets (LLINs) are an important public health strategy for malaria prevention adopted by most countries with endemic malaria. In addition to serving as physical barriers between mosquito vectors and individual users, toxicity and repellency induced by the pyrethroid insecticide-impregnated in LLINs can have important community-wide effects on vector density [1-3], and LLINs have been shown to reduce the burden of malaria, especially among children <five years and pregnant women [4,5] who are most vulnerable to malaria. LLINs are also one of the most cost-effective interventions, particularly in areas of high-malaria transmission [6]. "
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    ABSTRACT: Background: Universal coverage of long-lasting insecticide-treated bed nets (LLINs) for prevention of malaria was adopted by the Uganda National Malaria Control Programme in 2007. The first mass distribution of LLINs was implemented in 2010. Initially, a campaign targeted to households with pregnant women and children aged <five years was carried out, prior to a planned fill-in campaign to achieve universal LLIN coverage. This survey was conducted after the targeted distribution in central Uganda to assess progress in LLIN ownership and usage among children <five years. Methods: A two-stage, cluster-sample, cross-sectional household survey was carried out in early 2011 in Central region districts surveyed during the 2009 Malaria Indicator Survey (MIS). In the first sampling stage, 30 enumeration areas (EAs) were selected and all households were enumerated. Within each sampled EA, 20 households were randomly selected for interview using two questionnaires: a household questionnaire and a woman's questionnaire for all women aged 15-49 years, both modified from the MIS. Results: When compared to 2009 MIS results, household ownership of at least one LLIN increased by 47%, from 22 to 69% after the targeted campaign. LLIN use among children <five years increased by 40%, from 11 to 51%. Households with a child <six years old at the time of the survey, a proxy for those targeted, were significantly more likely to have received a campaign bed net (80.7 vs 35.2%, p < 0.001). LLIN ownership and use was equitable after the targeted campaign, with no significant differences by household wealth status.However, the proportion of households with at least one LLIN per two people was still low after the first campaign phase, increasing from 8.5 to 25.9%. Conclusions: The first phase of the campaign led to substantial increases in both LLIN ownership and equitable use among children <five years in the Central region. However, access to an LLIN within the household was still low after the first phase of the campaign, indicating the need for the universal fill-in campaign.
    Malaria Journal 05/2014; 13(1):185. DOI:10.1186/1475-2875-13-185 · 3.11 Impact Factor
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    • "Pregnant women, infants, and young children are particularly vulnerable to malaria [10,11]. Studies in sub-Saharan Africa have found that ITN use contributes to significant reductions in placental malaria, low birth weight, and still-births, as well as reduced morbidity and mortality among children under five [12,13]. Continuing net shortages make it critical to understand how households allocate nets among their members and whether the most biologically vulnerable groups are protected. "
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    ABSTRACT: Background Access to insecticide-treated bed nets has increased substantially in recent years, but ownership and use remain well below 100% in many malaria endemic areas. Understanding decision-making around net allocation in households with too few nets is essential to ensuring protection of the most vulnerable. This study explores household net allocation preferences and practices across four districts in Uganda. Methods Data collection consisted of eight focus group discussions, twelve in-depth interviews, and a structured questionnaire to inventory 107 sleeping spaces in 28 households. Results In focus group discussions and in-depth interviews, participants almost unanimously stated that pregnant women, infants, and young children should be prioritized when allocating nets. However, sleeping space surveys reveal that heads of household sometimes receive priority over children less than five years of age when households have too few nets to cover all members. Conclusions When asked directly, most net owners highlight the importance of allocating nets to the most biologically vulnerable household members. This is consistent with malaria behaviour change and health education messages. In actual allocation, however, factors other than biological vulnerability may influence who does and does not receive a net.
    Malaria Journal 05/2014; 13(1):183. DOI:10.1186/1475-2875-13-183 · 3.11 Impact Factor
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