Kangaroos harbour a vast range of parasites.

袋鼠身上有各种各样的寄生虫。

These symptoms may be referable to virus infection rather than parasites.

这些症状也许是由病毒感染引起的，而与寄生虫无关。

In nature, itching and scratching help animals get rid of parasites, plant material, or other unwanted baggage.

事实上，骚痒和抓挠帮助动物去掉寄生虫、植物体或其它不想要的垃圾。

Animals have parasites or carry a variety of viruses. Once transmitted to humans, it would be a very troublesome thing.

动物有寄生虫或携带各种各样的病毒。一旦传染给人类，这将会是非常麻烦的事。

It's possible that the cleanest and most highly evolved creatures where this topic is concerned are internal parasites, along with bee, wasp and ant larvae.

在这个话题中，最干净、最高度进化的生物可能是体内寄生虫，以及蜜蜂、黄蜂和蚂蚁幼虫。