Duncan R M, Jensen W L
J Wildl Dis. 1976 Jan;12(1):116-26. doi: 10.7589/0090-3558-12.1.116.
A survey of the sources of Clostridium botulinum type C toxin possibly utilized as food by aquatic birds in an epizootic area of avian botulism in northern Utah showed that living aquatic and terrestrial invertebrates normally found in close association with dead, decomposing birds commonly carried the toxin. Of 461 samples associated with 21 species of avian carcasses, 198 were toxin-positive. Invertebrate species not normally scavengers of vertebrate tissues were less commonly and less highly toxic, particularly when captured 30 cm or more from a carcass; six of 237 samples of such aquatic invertebrates low-level toxin. Of the species tested, blow fly larvae (Calliphoridae) were the most consistently and highly toxic, although others, particularly adult and larval stages of several species of beetles (Coleoptera), contained toxin at levels probably significant in the epizootiology of the disease. An estimated 0.05 to 0.25 g of the most toxic fly larvae or 15 g of the most toxic beetles tested carried a mediam lethal dose for an adult mallard duck. Examination of stomach contents of aquatic birds dead of botulism showed that some had consumed invertebrates.
在犹他州北部禽肉毒中毒的一个流行区域，对可能被水鸟当作食物利用的C型肉毒杆菌毒素来源进行的一项调查显示，通常与死亡、腐烂的鸟类密切相关的水生和陆生无脊椎动物活体通常携带该毒素。在与21种鸟类尸体相关的461个样本中，198个样本毒素呈阳性。通常不是脊椎动物组织食腐动物的无脊椎动物种类携带毒素的情况较少且毒性较低，尤其是当它们在距离尸体30厘米或更远的地方被捕获时；237个此类水生无脊椎动物样本中有6个含有低水平毒素。在所测试的物种中，丽蝇幼虫（丽蝇科）毒素含量最稳定且最高，不过其他物种，特别是几种甲虫（鞘翅目）的成虫和幼虫阶段，所含毒素水平在该病的动物流行病学中可能具有重要意义。据估计，所测试的毒性最强的蝇幼虫0.05至0.25克或毒性最强的甲虫15克所含毒素量对一只成年绿头鸭来说是半数致死剂量。对死于肉毒中毒的水鸟胃内容物的检查表明，有些鸟食用了无脊椎动物。
