Eberhard M L
Trop Med Parasitol. 1986 Dec;37(4):361-3.
The present study was undertaken to determine the longevity of a population of microfilariae in a natural host following the removal of the adult worms without drug intervention. Four squirrel monkeys previously infected with Dipetalonema gracile were allowed to develop stable microfilaremias. All adult worms were then removed surgically from the peritoneal cavity. Weekly microfilaria counts were made on each animal and the decline in microfilariae recorded. At the time of adult worm removal, microfilaremias ranged from 750 to 12,500 mf/ml. The observed decline in microfilaria densities was gradual, but steady, in all animals. Microfilariae persisted in 1-ml blood samples for 60, 62, 91, and 101 weeks following removal of adult worms. The results indicate clearly that in a naturally produced population, in a natural definitive host, microfilariae survive for 60 to 100 weeks. The gradual decrease in microfilarial densities would appear to be the result of the death of specific batches or broods of microfilariae. The microfilariae which persisted in the blood the longest undoubtedly represent those which were produced just prior to the removal of the adult worms. It is postulated that because of the long life-span of microfilariae, female worms are not called upon to produce a continual supply of microfilariae, nor is the need for mating as frequent as might be expected. Equally important, the number of microfilariae which the host is called upon to phagocytize is considerably smaller than previously suggested.
本研究旨在确定在无药物干预的情况下清除成虫后，自然宿主体内微丝蚴群体的存活时间。选取4只先前感染纤细双瓣线虫的松鼠猴，使其发展为稳定的微丝蚴血症。然后通过手术从腹腔中清除所有成虫。每周对每只动物进行微丝蚴计数，并记录微丝蚴数量的下降情况。在清除成虫时，微丝蚴血症范围为每毫升750至12,500条微丝蚴。在所有动物中，观察到的微丝蚴密度下降是逐渐的，但较为稳定。在清除成虫后，1毫升血液样本中的微丝蚴持续存在了60、62、91和101周。结果清楚地表明，在自然产生的群体中，在自然终末宿主体内，微丝蚴可存活60至100周。微丝蚴密度的逐渐下降似乎是特定批次或群体的微丝蚴死亡的结果。在血液中持续时间最长的微丝蚴无疑是在清除成虫之前产生的那些。据推测，由于微丝蚴寿命长，雌虫不需要持续产生微丝蚴供应，交配的频率也不像预期的那么高。同样重要的是，宿主需要吞噬的微丝蚴数量比之前认为的要少得多。
