Barrett Carrie, Chiphwanya John, Mkwanda Square, Matipula Dorothy E, Ndhlovu Paul, Chaponda Limbikani, Turner Joseph D, Giorgi Emanuele, Betts Hannah, Martindale Sarah, Taylor Mark J, Read Jonathan M, Kelly-Hope Louise A
Centre for Neglected Tropical Disease, Department of Tropical Disease Biology, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, United Kingdom.
National Lymphatic Filariasis Elimination Programme, Ministry of Health, Lilongwe, Malawi.
PLoS Negl Trop Dis. 2024 Mar 25;18(3):e0012056. doi: 10.1371/journal.pntd.0012056. eCollection 2024 Mar.
In 2020 the World Health Organization (WHO) declared that Malawi had successfully eliminated lymphatic filariasis (LF) as a public health problem. Understanding clinical case distributions at a national and sub-national level is important, so essential care packages can be provided to individuals living with LF symptoms. This study aimed to develop a national database and map of LF clinical cases across Malawi using geostatistical modelling approaches, programme-identified clinical cases, antigenaemia prevalence and climate information.
LF clinical cases identified through programme house-to-house surveys across 90 sub-district administrative boundaries (Traditional Authority (TA)) and antigenaemia prevalence from 57 sampled villages in Malawi were used in a two-step geostatistical modelling process to predict LF clinical cases across all TAs of the country. First, we modelled antigenaemia prevalence in relation to climate covariates to predict nationwide antigenaemia prevalence. Second, we modelled clinical cases for unmapped TAs based on our antigenaemia prevalence spatial estimates.
The models estimated 20,938 (95% CrI 18,091 to 24,071) clinical cases in unmapped TAs (70.3%) in addition to the 8,856 (29.7%), programme-identified cases in mapped TAs. In total, the overall national number of LF clinical cases was estimated to be 29,794 (95% CrI 26,957 to 32,927). The antigenaemia prevalence and clinical case mapping and modelling found the highest burden of disease in Chikwawa and Nsanje districts in the Southern Region and Karonga district in the Northern Region of the country.
The models presented in this study have facilitated the development of the first national LF clinical case database and map in Malawi, the first endemic country in sub-Saharan Africa. It highlights the value of using existing LF antigenaemia prevalence and clinical case data together with modelling approaches to produce estimates that may be used for the WHO dossier requirements, to help target limited resources and implement long-term health strategies.
2020年，世界卫生组织（WHO）宣布马拉维已成功消除淋巴丝虫病（LF）这一公共卫生问题。了解全国和次国家级层面的临床病例分布情况很重要，这样就能为有LF症状的患者提供必要的护理套餐。本研究旨在利用地理统计建模方法、项目确定的临床病例、抗原血症患病率和气候信息，建立一个马拉维全国LF临床病例数据库并绘制地图。
通过在90个次县级行政区（传统权威区（TA））进行的逐户项目调查确定的LF临床病例，以及来自马拉维57个抽样村庄的抗原血症患病率，被用于一个两步地理统计建模过程，以预测该国所有TA区的LF临床病例。首先，我们对与气候协变量相关的抗原血症患病率进行建模，以预测全国范围内的抗原血症患病率。其次，我们根据抗原血症患病率的空间估计值，对未绘制地图的TA区的临床病例进行建模。
模型估计，除了在已绘制地图的TA区有8856例（29.7%）由项目确定的病例外，在未绘制地图的TA区还有20938例（95% CrI 18091至24071）临床病例。总体而言，全国LF临床病例总数估计为29794例（95% CrI 26957至32927）。抗原血症患病率以及临床病例的绘图和建模显示，该国南部地区的奇夸瓦和恩桑杰区以及北部地区的卡龙加区疾病负担最高。
本研究中提出的模型推动了马拉维首个全国LF临床病例数据库和地图的建立，马拉维是撒哈拉以南非洲的首个流行国家。它凸显了将现有的LF抗原血症患病率和临床病例数据与建模方法结合使用的价值，以得出可用于满足WHO档案要求的估计值，帮助确定有限资源的目标并实施长期健康战略。
