Tekle Afework H, Zouré Honorath G M, Noma Mounkaila, Boussinesq Michel, Coffeng Luc E, Stolk Wilma A, Remme Jan H F
African Programme for Onchocerciasis Control, Ouagadougou, Burkina Faso.
Institut de Recherche pour le Développement (IRD), Montpellier, France.
Infect Dis Poverty. 2016 Jun 27;5(1):66. doi: 10.1186/s40249-016-0160-7.
The African Programme for Onchocerciasis Control (APOC) was created in 1995 to establish community-directed treatment with ivermectin (CDTi) in order to control onchocerciasis as a public health problem in 20 African countries that had 80 % of the global disease burden. When research showed that CDTi may ultimately eliminate onchocerciasis infection, APOC was given in 2008 the additional objective to determine when and where treatment can be safely stopped. We report the results of epidemiological evaluations undertaken from 2008 to 2014 to assess progress towards elimination in CDTi areas with ≥6 years treatment.
Skin snip surveys were undertaken in samples of first-line villages to determine the prevalence of O. volvulus microfilariae. There were two evaluation phases. The decline in prevalence was evaluated in phase 1A. Observed and model-predicted prevalences were compared after correcting for endemicity level and treatment coverage. Bayesian statistics and Monte Carlo simulation were used to classify the decline in prevalence as faster than predicted, on track or delayed. Where the prevalence approached elimination levels, phase 1B was launched to determine if treatment could be safely stopped. Village sampling was extended to the whole CDTi area. Survey data were analysed within a Bayesian framework to determine if stopping criteria (overall prevalence <1.4 % and maximum stratum prevalence <5 %) were met.
In phase 1A 127 665 people from 639 villages in 54 areas were examined. The prevalence had fallen dramatically. The decline in prevalence was faster than predicted in 23 areas, on track in another 23 and delayed in eight areas. In phase 1B 108 636 people in 392 villages were examined in 22 areas of which 13 met the epidemiological criteria for stopping treatment. Overall, 32 areas (25.4 million people) had reached or were close to elimination, 18 areas (17.4 million) were on track but required more years treatment, and in eight areas (10.4 million) progress was unsatisfactory.
Onchocerciasis has been largely controlled as a public health problem. Great progress has been made towards elimination which already appears to have been achieved for millions of people. For most APOC countries, nationwide onchocerciasis elimination is within reach.
非洲盘尾丝虫病控制计划（APOC）于1995年设立，旨在开展伊维菌素社区定向治疗（CDTi），以控制盘尾丝虫病这一公共卫生问题，该病在20个非洲国家构成了全球80%的疾病负担。当研究表明CDTi最终可能消除盘尾丝虫病感染时，APOC在2008年又增加了一项任务，即确定何时何地可以安全停止治疗。我们报告了2008年至2014年进行的流行病学评估结果，以评估在接受了≥6年治疗的CDTi地区在消除方面取得的进展。
在一线村庄的样本中进行皮肤切片检查，以确定盘尾丝虫微丝蚴的流行率。有两个评估阶段。在1A阶段评估流行率的下降情况。在校正了流行程度和治疗覆盖率后，比较观察到的和模型预测的流行率。使用贝叶斯统计和蒙特卡罗模拟将流行率的下降分类为快于预测、符合预期或延迟。当流行率接近消除水平时，启动1B阶段以确定是否可以安全停止治疗。村庄抽样扩展到整个CDTi地区。在贝叶斯框架内分析调查数据，以确定是否满足停止标准（总体流行率<1.4%且最高分层流行率<5%）。
在1A阶段，对54个地区639个村庄的127665人进行了检查。流行率大幅下降。23个地区的流行率下降快于预测，另外23个地区符合预期，8个地区延迟。在1B阶段，对22个地区392个村庄的108636人进行了检查，其中13个地区符合停止治疗所需的流行病学标准。总体而言，32个地区（2540万人）已达到或接近消除水平，18个地区（1740万人）进展符合预期，但还需要更多年的治疗，8个地区（1040万人）进展不令人满意。
盘尾丝虫病作为一个公共卫生问题已得到很大程度的控制。在消除方面已取得巨大进展，对数以百万计的人而言，消除似乎已经实现。对大多数APOC国家来说，在全国范围内消除盘尾丝虫病已指日可待。
