Cupp E W, Ochoa J O, Collins R C, Cupp M S, Gonzales-Peralta C, Castro J, Zea-Flores G
Department of Entomology, University of Arizona, Tucson.
Am J Trop Med Hyg. 1992 Aug;47(2):170-80. doi: 10.4269/ajtmh.1992.47.170.
The effects of biannual ivermectin treatment at the community level on transmission of Onchocerca volvulus during the dry season were measured over a 30-month period in Guatemala. In the Los Tarrales Transmission Zone, an area encompassing three villages, significant changes occurred in both the prevalence and quantity of infection in the Simulium ochraceum vector population. These included a 76% reduction in females with infective stage larvae (L3S) and an 80% reduction in number of L3S per 1,000 parous flies. Significant reductions in both the mean infective biting density (IBD) and mean transmission potential (TP) also occurred. In Santa Emilia, the prevalence of infection with L3S in S. ochraceum was significantly reduced by 77% from the baseline value. The number of O. volvulus L3S per 1,000 parous flies was also reduced by 92%. Changes in both the IBD and TP were substantial but not significant due to the high degree of variance in the occurrence of O. volvulus L3S in the vector population. This was due, in part, to the movement of infected migrant workers into the finca (coffee farm). In Los Andes, four recurrent treatments successfully blocked transmission of infective stage larvae. Prevalence (flies with all stages of developing larvae) in the vector population was reduced by 89% over the two-year period; yearly reductions in both the IBD and TP were also highly significant, ultimately ending in zero values. This finding is particularly striking since prior to treatment, Los Andes exhibited the highest IBD of the three study locations and the second highest TP.
在危地马拉，对社区层面每半年一次的伊维菌素治疗在旱季期间对盘尾丝虫传播的影响进行了为期30个月的测量。在洛斯塔拉莱斯传播区，这是一个涵盖三个村庄的区域，赭色蚋媒介种群的感染率和感染数量均发生了显著变化。这些变化包括感染期幼虫（L3S）的雌蚋减少了76%，每1000只已产卵雌蚋的L3S数量减少了80%。平均感染叮咬密度（IBD）和平均传播潜力（TP）也显著降低。在圣埃米莉亚，赭色蚋中L3S的感染率较基线值显著降低了77%。每1000只已产卵雌蚋中的盘尾丝虫L3S数量也减少了92%。由于媒介种群中盘尾丝虫L3S出现的高度变异性，IBD和TP的变化虽然很大，但并不显著。部分原因是受感染的流动工人进入了种植园（咖啡农场）。在洛斯安第斯，四次反复治疗成功阻断了感染期幼虫的传播。在两年期间，媒介种群中的患病率（处于发育各阶段幼虫的蚋）降低了89%；IBD和TP的年度降低也非常显著，最终降至零值。这一发现尤为引人注目，因为在治疗前，洛斯安第斯的IBD在三个研究地点中最高，TP在三个研究地点中排第二高。
