Vector Biology Department, Liverpool School of Tropical Medicine, Liverpool, UK.
Malawi-Liverpool Wellcome Trust Clinical Research Programme, Blantyre, Malawi.
Malar J. 2023 Jan 13;22(1):16. doi: 10.1186/s12936-023-04448-y.
To achieve malaria elimination it is essential to understand the impact of insecticide-treated net (ITNs) programmes. Here, the impact of ITN access and use on malaria prevalence in children in Malawi was investigated using Malaria Indicator Survey (MIS) data.
MIS data from 2012, 2014 and 2017 were used to investigate the relationship between malaria prevalence in children (6-59 months) and ITN use. Generalized linear modelling (GLM), geostatistical mixed regression modelling and non-stationary GLM were undertaken to evaluate trends, spatial patterns and local dynamics, respectively.
Malaria prevalence in Malawi was 27.1% (95% CI 23.1-31.2%) in 2012 and similar in both 2014 (32.1%, 95% CI 25.5-38.7) and 2017 (23.9%, 95% CI 20.3-27.4%). ITN coverage and use increased during the same time period, with household ITN access growing from 19.0% (95% CI 15.6-22.3%) of households with at least 1 ITN for every 2 people sleeping in the house the night before to 41.7% (95% CI 39.1-44.4%) and ITN use from 41.1% (95% CI 37.3-44.9%) of the population sleeping under an ITN the previous night to 57.4% (95% CI 55.0-59.9%). Both the geostatistical and non-stationary GLM regression models showed child malaria prevalence had a negative association with ITN population access and a positive association with ITN use although affected by large uncertainties. The non-stationary GLM highlighted the spatital heterogeneity in the relationship between childhood malaria and ITN dynamics across the country.
Malaria prevalence in children under five had a negative association with ITN population access and a positive association with ITN use, with spatial heterogeneity in these relationships across Malawi. This study presents an important modelling approach that allows malaria control programmes to spatially disentangle the impact of interventions on malaria cases.
要实现消除疟疾，就必须了解经杀虫剂处理的蚊帐（ITN）项目的影响。本研究利用疟疾指标调查（MIS）数据，调查了马拉维儿童中 ITN 可及性和使用对疟疾流行率的影响。
利用 2012 年、2014 年和 2017 年的 MIS 数据，研究了儿童（6-59 个月）疟疾流行率与 ITN 使用之间的关系。采用广义线性模型（GLM）、地质统计学混合回归模型和非平稳 GLM 分别评估趋势、空间模式和局部动态。
2012 年，马拉维的疟疾流行率为 27.1%（95%CI 23.1-31.2%），2014 年和 2017 年相似，分别为 32.1%（95%CI 25.5-38.7%）和 23.9%（95%CI 20.3-27.4%）。在此期间，ITN 覆盖率和使用率均有所增加，家庭 ITN 可及性从每 2 人睡在屋内的前一晚有 1 顶 ITN 的家庭占 19.0%（95%CI 15.6-22.3%）增长到 41.7%（95%CI 39.1-44.4%），而 ITN 使用量从前一晚有 41.1%（95%CI 37.3-44.9%）的人口在 ITN 下睡觉增长到 57.4%（95%CI 55.0-59.9%）。地质统计学和非平稳 GLM 回归模型均显示，儿童疟疾流行率与 ITN 人群可及性呈负相关，与 ITN 使用呈正相关，但受较大不确定性影响。非平稳 GLM 突出了全国范围内儿童疟疾与 ITN 动态之间关系的空间异质性。
五岁以下儿童疟疾流行率与 ITN 人群可及性呈负相关，与 ITN 使用呈正相关，马拉维各地之间的关系存在空间异质性。本研究提出了一种重要的建模方法，使疟疾控制规划能够在空间上分解干预措施对疟疾病例的影响。
