Hörchner F
Institute für Parasitologie und Tropenveterinärmedizin, Freie Universität Berlin, FRG.
Trop Med Parasitol. 1990 Dec;41(4):422-4.
As the major contagious epidemics in the tropics are today more or less under control, the most important diseases of livestock are due to parasitic infections. Precise knowledge concerning the biology of parasites and their seasonality is a prerequisite for any control strategy. Therefore, epidemiological investigations into the effect of helminths on ruminant livestock production must include I. A vertical section through the age dependent helminthic burden of a representative number of animals of a given population, i.e. the sampling of faeces at regular intervals during the first 18 months of life. II. Investigations into the horizontal development of the helminthic situation, whether soil-transmitted and/or vector-transmitted. a. The seasonal fluctuation of egg excretion from gastrointestinal nematodes. b. The seasonal incidence of nematode larvae on pastures. c. The seasonal survival time of nematodes larvae on pastures. III. The seasonal fluctuation of vector snails and their incidence of infection with trematode larvae. For the economic evaluation of control measures it is necessary that the following parameters should be recorded: The age dependent mortality rate, the development of the average body weight, the birth/slaughter weight, the age at first calving and the calving intervals.
由于热带地区的主要传染性流行病如今或多或少已得到控制，家畜最重要的疾病是由寄生虫感染引起的。关于寄生虫生物学及其季节性的精确知识是任何控制策略的先决条件。因此，对蠕虫对反刍动物家畜生产影响的流行病学调查必须包括：一、对特定种群中代表性数量动物的年龄依赖性蠕虫负担进行垂直剖面分析，即在动物生命的前18个月定期采集粪便样本。二、调查蠕虫情况的水平发展，无论是土壤传播的和/或媒介传播的。a. 胃肠线虫虫卵排泄的季节性波动。b. 牧场上线虫幼虫的季节性发生率。c. 线虫幼虫在牧场上的季节性存活时间。三、媒介蜗牛的季节性波动及其感染吸虫幼虫的发生率。为了对控制措施进行经济评估，有必要记录以下参数：年龄依赖性死亡率、平均体重的增长、出生/屠宰体重、首次产犊年龄和产犊间隔。
