Rangel-Ruiz L J, Marquez-Izquierdo R, Bravo-Nogueira G
División Académica de Ciencias Biológicas, Universidad Juárez Autónoma de Tabasco, Mexico.
Vet Parasitol. 1999 Feb 25;81(2):119-27. doi: 10.1016/s0304-4017(98)00152-6.
To establish seasonal trends in infection and maturity of Fasciola hepatica in cattle in relation to macroclimatic factors, 2730 condemned livers were examined from March 1989 to February 1992. Livestock came from Jalapa, Tacotalpa and Teapa, all municipalities in Tabasco State. Flukes were collected monthly and separated into three different maturation stages. Mean numbers of flukes collected were determined. The analysis of the maturation stages detected in cattle showed: (a) F. hepatica matured throughout the year at all three sites; (b) the greatest mean fluke's burdens were found in Jalapa and the lowest in Teapa; large parasite populations were significantly higher from February to September than in July and/or August; (c) persistence of mature, gravid F. hepatica indicated that parasite eggs are shed throughout the year; (d) recruitment of F. hepatica occurred throughout the year with two major periods of infection, the first and main period during the dry season (from February to June), and a second minor infection period, during the rainy season (from August to October); (e) a close relationship was observed between the seasonal infection pattern in cattle and the seasonal infection pattern in snails, as well as fluctuations in the snail population according to rainfall and temperature variation.
为确定与宏观气候因素相关的牛肝片吸虫感染和成熟的季节性趋势，1989年3月至1992年2月期间检查了2730份废弃肝脏。家畜来自塔巴斯科州的哈拉帕、塔科塔尔帕和特阿帕这三个市。每月收集吸虫并分为三个不同的成熟阶段。确定收集到的吸虫的平均数量。对牛体内检测到的成熟阶段的分析表明：(a) 肝片吸虫在所有三个地点全年均成熟；(b) 在哈拉帕发现的吸虫平均负担最重，在特阿帕最轻；2月至9月的大型寄生虫种群明显高于7月和/或8月；(c) 成熟、妊娠的肝片吸虫持续存在表明寄生虫卵全年排出；(d) 肝片吸虫全年均有补充，有两个主要感染期，第一个也是主要感染期在旱季（2月至6月），第二个次要感染期在雨季（8月至10月）；(e) 观察到牛的季节性感染模式与蜗牛的季节性感染模式之间密切相关，以及蜗牛种群根据降雨和温度变化的波动情况。
