Institute for Health Metrics and Evaluation, University of Washington, Seattle, WA, 98121, USA.
BMC Med. 2022 Sep 7;20(1):293. doi: 10.1186/s12916-022-02486-y.
Onchocerciasis is a disease caused by infection with Onchocerca volvulus, which is transmitted to humans via the bite of several species of black fly, and is responsible for permanent blindness or vision loss, as well as severe skin disease. Predominantly endemic in parts of Africa and Yemen, preventive chemotherapy with mass drug administration of ivermectin is the primary intervention recommended for the elimination of its transmission.
A dataset of 18,116 geo-referenced prevalence survey datapoints was used to model annual 2000-2018 infection prevalence in Africa and Yemen. Using Bayesian model-based geostatistics, we generated spatially continuous estimates of all-age 2000-2018 onchocerciasis infection prevalence at the 5 × 5-km resolution as well as aggregations to the national level, along with corresponding estimates of the uncertainty in these predictions.
As of 2018, the prevalence of onchocerciasis infection continues to be concentrated across central and western Africa, with the highest mean estimates at the national level in Ghana (12.2%, 95% uncertainty interval [UI] 5.0-22.7). Mean estimates exceed 5% infection prevalence at the national level for Cameroon, Central African Republic, Democratic Republic of the Congo (DRC), Guinea-Bissau, Sierra Leone, and South Sudan.
Our analysis suggests that onchocerciasis infection has declined over the last two decades throughout western and central Africa. Focal areas of Angola, Cameroon, the Democratic Republic of the Congo, Ethiopia, Ghana, Guinea, Mali, Nigeria, South Sudan, and Uganda continue to have mean microfiladermia prevalence estimates exceeding 25%. At and above this level, the continuation or initiation of mass drug administration with ivermectin is supported. If national programs aim to eliminate onchocerciasis infection, additional surveillance or supervision of areas of predicted high prevalence would be warranted to ensure sufficiently high coverage of program interventions.
盘尾丝虫病是由感染旋盘尾丝虫引起的疾病，通过几种黑蝇的叮咬传播给人类，可导致永久性失明或视力丧失，以及严重的皮肤疾病。该病主要流行于非洲和也门部分地区，用伊维菌素进行大规模药物治疗是推荐用于消除其传播的主要干预措施。
我们使用了一个包含 18116 个地理位置参考的流行率调查数据点数据集，对 2000 年至 2018 年期间非洲和也门的年度感染流行率进行建模。我们使用基于贝叶斯模型的地质统计学，生成了 2000 年至 2018 年全年龄段盘尾丝虫感染流行率的连续空间估计值，分辨率为 5×5 公里，并对其进行了国家级聚合，同时还提供了这些预测的不确定性估计值。
截至 2018 年，盘尾丝虫感染的流行率仍然集中在非洲中部和西部，在国家级层面上，加纳的平均估计值最高（12.2%，95%置信区间 [CI] 5.0-22.7）。在国家级层面上，喀麦隆、中非共和国、刚果民主共和国、几内亚比绍、塞拉利昂和南苏丹的感染流行率均值超过 5%。
我们的分析表明，在过去二十年中，整个西非和中非的盘尾丝虫感染有所下降。安哥拉、喀麦隆、刚果民主共和国、埃塞俄比亚、加纳、几内亚、马里、尼日利亚、南苏丹和乌干达等国家的局部地区仍有超过 25%的微丝蚴流行率均值估计值。在这一水平及以上，支持继续或启动用伊维菌素进行大规模药物治疗。如果国家项目旨在消除盘尾丝虫感染，需要对预测的高流行地区进行额外的监测或监督，以确保项目干预措施有足够高的覆盖率。
