在布基纳法索科莫埃河谷复发性盘尾丝虫病传播后的昆虫学评估。

Entomological assessment of the transmission following recrudescence of onchocerciasis in the Comoé Valley, Burkina Faso.

机构信息

Ministère de l'Enseignement Supérieur, de la Recherche Scientifique et de l'Innovation, Institut de Recherche en Sciences de la Santé (IRSS), Direction Régionale de l'Ouest, BP 545, Bobo Dioulasso 01, Burkina Faso.

Ministère de la Santé, Direction Générale de la Santé, BP 7003, Ouagadougou 01, Burkina Faso.

出版信息

Parasit Vectors. 2019 Jan 15;12(1):34. doi: 10.1186/s13071-019-3290-5.

BACKGROUND

Onchocerciasis, or river blindness, is a dermal filariasis caused by infection with the nematode parasite Onchocerca volvulus, transmitted to humans through the bites of blackflies of the genus Simulium. Despite the decade-long West African Regional Programme for the Elimination of Onchocerciasis, involving the mass administration of ivermectin to populations in endemic areas, recrudescence has occurred. An example is in the Cascades Region of south-west Burkina Faso where the resumption of transmission had resulted in infection prevalences of up to 70% in some villages. In 2011, a strategy for community-directed distribution of ivermectin (CDTI) was set up to respond to this worrying re-emergence. Here, we report on a study of Onchocerca spp. transmission in the affected area carried out from January to December 2012. Every month, host-seeking adult females of the S. damnosum complex were collected at sites on the River Comoé near the four villages (Bodadiougou, Bolibana, Badara Karaboro and Badara Dogossè) that had recorded the highest prevalences in 2010. Collected blackflies were dissected and infective larvae were identified using the O-150 PCR method.

RESULTS

A total of 9114 S. damnosum (s.l.) adult females were collected, of which 5142 were parous (56.4%) and 78 (1.51%) were infective carrying a total of 137 infective larvae. The annual transmission potential (ATP) was calculated as 0, 30, 255 and 771 infective larvae/man/year in Badara Dogossè, Bolibana, Badara Karaboro and Bodadiougou, respectively. Transmission levels in the latter two are of particular concern as they were higher than 100 infective larvae/person/year, the designated minimum threshold required for elimination of severe pathology, including damage to vision.

CONCLUSIONS

These results confirm that recrudescence of onchocerciasis has occurred, and that transmission of O. volvulus was active at sites on the Comoé River in the Cascades region in 2012. In accordance with WHO recommendations, CDTI should be continued and the situation in the Cascades region should be closely monitored if further spread of this outbreak is to be avoided.

背景

盘尾丝虫病，又称河盲症，是一种由线虫寄生虫盘尾丝虫引起的皮肤丝虫病，通过黑蝇属的黑蝇叮咬传播给人类。尽管长达十年的西非区域消灭盘尾丝虫病计划，包括在流行地区大规模使用伊维菌素对人群进行治疗，但仍出现了复发。一个例子是在布基纳法索西南部的 Cascades 地区，那里传播的恢复导致一些村庄的感染率高达 70%。2011 年，建立了社区定向分发伊维菌素（CDTI）的策略来应对这种令人担忧的再次出现。在这里，我们报告了 2012 年 1 月至 12 月在受影响地区进行的盘尾丝虫属传播研究。每月，在记录到 2010 年最高流行率的四个村庄（Bodadiougou、Bolibana、Badara Karaboro 和 Badara Dogossè）附近的 Comoé 河上采集宿主寻找的黑蝇成年雌性。采集到的黑蝇被解剖，并用 O-150 PCR 方法鉴定感染性幼虫。

结果

共采集到 9114 只沙蝇（s.l.）成年雌性，其中 5142 只已产（56.4%），78 只携带感染性幼虫（1.51%），共携带 137 条感染性幼虫。Badara Dogossè、Bolibana、Badara Karaboro 和 Bodadiougou 的年传播潜力（ATP）分别计算为 0、30、255 和 771 条感染性幼虫/人/年。后两者的传播水平尤其令人担忧，因为它们高于 100 条感染性幼虫/人/年，这是消除严重病理包括视力损害所需的最低阈值。