African Programme for Onchocerciasis Control, World Health Organization, Ouagadougou, Burkina Faso.
PLoS Negl Trop Dis. 2011 Jun;5(6):e1210. doi: 10.1371/journal.pntd.0001210. Epub 2011 Jun 28.
Loiasis is a major obstacle to ivermectin treatment for onchocerciasis control and lymphatic filariasis elimination in central Africa. In communities with a high level of loiasis endemicity, there is a significant risk of severe adverse reactions to ivermectin treatment. Information on the geographic distribution of loiasis in Africa is urgently needed but available information is limited. The African Programme for Onchocerciasis Control (APOC) undertook large scale mapping of loiasis in 11 potentially endemic countries using a rapid assessment procedure for loiasis (RAPLOA) that uses a simple questionnaire on the history of eye worm.
METHODOLOGY/PRINCIPAL FINDINGS: RAPLOA surveys were done in a spatial sample of 4798 villages covering an area of 2500×3000 km centred on the heartland of loiasis in Africa. The surveys showed high risk levels of loiasis in 10 countries where an estimated 14.4 million people live in high risk areas. There was a strong spatial correlation among RAPLOA data, and kriging was used to produce spatially smoothed contour maps of the interpolated prevalence of eye worm and the predictive probability that the prevalence exceeds 40%.
CONCLUSION/SIGNIFICANCE: The contour map of eye worm prevalence provides the first global map of loiasis based on actual survey data. It shows a clear distribution with two zones of hyper endemicity, large areas that are free of loiasis and several borderline or intermediate zones. The surveys detected several previously unknown hyperendemic foci, clarified the distribution of loiasis in the Central African Republic and large parts of the Republic of Congo and the Democratic Republic of Congo for which hardly any information was available, and confirmed known loiasis foci. The new maps of the prevalence of eye worm and the probability that the prevalence exceeds the risk threshold of 40% provide critical information for ivermectin treatment programs among millions of people in Africa.
罗阿丝虫病是中部非洲使用伊维菌素治疗盘尾丝虫病控制和淋巴丝虫病消除的主要障碍。在罗阿丝虫病高度流行的社区中，使用伊维菌素治疗有发生严重不良反应的重大风险。迫切需要有关非洲罗阿丝虫病地理分布的信息，但现有信息有限。非洲盘尾丝虫病控制规划（APOC）使用一种简单的眼部蠕虫病史问卷的罗阿丝虫快速评估程序（RAPLOA），在 11 个潜在流行国家进行了大规模罗阿丝虫病绘图。
方法/主要发现：RAPLOA 调查在一个覆盖面积为 2500×3000 平方公里的空间样本中的 4798 个村庄中进行，该区域以非洲罗阿丝虫病中心地带为中心。调查显示，10 个国家的罗阿丝虫病风险水平较高，估计有 1440 万人生活在高风险地区。RAPLOA 数据之间存在很强的空间相关性，因此使用克里金插值法生成了眼部蠕虫流行率的空间平滑等高线图，以及流行率超过 40%的预测概率等高线图。
结论/意义：眼部蠕虫流行率等高线图提供了第一个基于实际调查数据的全球罗阿丝虫病地图。它显示了一个清晰的分布，有两个高度流行区、大面积无罗阿丝虫病区和几个边界或中间区。调查发现了几个以前未知的高度流行焦点，澄清了中非共和国和刚果共和国以及刚果民主共和国的罗阿丝虫病分布情况，因为这些地区几乎没有任何信息，并且确认了已知的罗阿丝虫病焦点。眼部蠕虫流行率的新地图和流行率超过 40%风险阈值的概率为非洲数百万人的伊维菌素治疗计划提供了关键信息。
