Banic Dalma M, Calvão-Brito Regina H S, Marchon-Silva Verônica, Schuertez Joana C, de Lima Pinheiro Luís Renerys, da Costa Alves Marilene, Têva Antônio, Maia-Herzog Marilza
Laboratório de Pesquisas em Malária, Instituto Oswaldo Cruz, Manguinhos, Rio de Janeiro, Brazil.
Acta Trop. 2009 Nov;112(2):125-30. doi: 10.1016/j.actatropica.2009.07.009. Epub 2009 Jul 15.
In the current study, it was assessed, for the first time, the effect of ivermectin treatment administered twice a year on the prevalence and morbidity of onchocerciasis in the hyperendemic Yanomami communities of the Roraima State (Brazil). Physical and parasitological examinations were carried out every 6 months until six drug rounds of treatment were completed. The coverage during the six rounds of ivermectin treatment ranged from 89% to 92% of the eligible Yanomami population. Overall, comparison of results at pre-treatment with results after six rounds of treatment, the prevalence of infection had declined from 87% to 42% (P<0.0001, CI 95%=0.05-0.22); the community microfilarial load (CMFL) fell from 1.17 to 0.53Mf/mg of skin; and the crude intensity of infection (MFL-Total) decreased from 18.95 to 1.96Mf/mg of skin during the same period (P<0.0001, for both microfilarial loads). Although no significant difference was observed between microfilarial densities in skin snips from iliac crest and scapula after the 6th round of ivermectin treatment it was observed that the prevalence of positive skin snips was significantly higher when skin snips were taken from iliac crest (42%) than from scapula (8%) (P=0.001, CI 95%=3.41-22.67). After six rounds of ivermectin treatments, no significant differences were observed in the prevalences of palpable nodules and of onchodermatitis in relation to pre-treatment prevalences, from 45% to 41% and from 17% to 20% (P>0.05, for both). These findings suggest that mass population treatment should continue without interruption and achieve higher levels of drug coverage in order to alleviate disease manifestations and interrupt infection transmission to hasten the elimination of onchocerciasis in Yanomami communities. In addition, the sensitivity of iliac crest snips for parasitological assessment in epidemiological surveillance of Yanomami communities may increase the acceptance of the population in biopsy sampling and seems to be a good choice for assessing the success of control programs.
在当前研究中，首次评估了每年两次服用伊维菌素治疗对巴西罗赖马州高度流行的雅诺马马社区盘尾丝虫病患病率和发病率的影响。每6个月进行一次体格检查和寄生虫学检查，直至完成六轮药物治疗。六轮伊维菌素治疗期间的覆盖率在符合条件的雅诺马马人群的89%至92%之间。总体而言，将治疗前的结果与六轮治疗后的结果进行比较，感染患病率从87%降至42%（P<0.0001，95%置信区间=0.05 - 0.22）；社区微丝蚴负荷（CMFL）从1.17降至0.53条微丝蚴/毫克皮肤；同期感染的粗强度（总微丝蚴数）从18.95降至1.96条微丝蚴/毫克皮肤（两种微丝蚴负荷的P均<0.0001）。尽管在第六轮伊维菌素治疗后，取自髂嵴和肩胛骨的皮肤切片中的微丝蚴密度之间未观察到显著差异，但观察到取自髂嵴的皮肤切片阳性患病率（42%）显著高于取自肩胛骨的皮肤切片（8%）（P = 0.001，95%置信区间=3.41 - 22.67）。在进行六轮伊维菌素治疗后，与治疗前患病率相比，可触及结节和盘尾性皮炎的患病率分别从45%降至41%和从17%升至20%，均未观察到显著差异（两者P>0.05）。这些发现表明，大规模人群治疗应持续不间断进行，并实现更高水平的药物覆盖率，以减轻疾病表现并中断感染传播，从而加速雅诺马马社区盘尾丝虫病的消除。此外，在雅诺马马社区的流行病学监测中，髂嵴切片用于寄生虫学评估的敏感性可能会提高人群对活检采样的接受度，并且似乎是评估控制项目成功与否的一个不错选择。
