Monis P T, Thompson R C A
Australian Water Quality Centre, South Australian Water Corporation and Cooperative Research Centre for Water Quality and Treatment, Private Mail Bag 3, SA 5108, Salisbury, Australia.
Infect Genet Evol. 2003 Nov;3(4):233-44. doi: 10.1016/j.meegid.2003.08.003.
Giardia and Cryptosporidium are enteric protozoan parasites that infect a wide range of vertebrate hosts. Both are transmitted either by direct faecal/oral contact or by the ingestion of contaminated food or water. The discovery of morphologically similar organisms infecting humans and a variety of mammals and birds has led to the proposal that both Cryptosporidium and Giardia are zoonotic (i.e. transmitted in nature between humans and animals). Transmission between humans and animals has been supported by cross-infection studies. However, closer examination of many of these studies reveals limitations in the methodologies utilised. More recent molecular genetic studies have demonstrated considerable genetic diversity among isolates of the same species of Giardia and Cryptosporidium, suggesting that these species are in fact species complexes and that some of these novel species may be host-specific. This paper will critically examine the evidence for the zoonotic transmission of these parasites.
贾第虫和隐孢子虫是肠道原生动物寄生虫，可感染多种脊椎动物宿主。两者均通过直接粪口接触或摄入受污染的食物或水传播。在人类以及多种哺乳动物和鸟类中发现形态相似的感染生物，这使得人们提出隐孢子虫和贾第虫都是人畜共患病原体（即，在自然界中可在人类和动物之间传播）。人畜共患传播已得到交叉感染研究的支持。然而，对其中许多研究的进一步审视发现了所采用方法的局限性。最近的分子遗传学研究表明，同一物种的贾第虫和隐孢子虫分离株之间存在相当大的遗传多样性，这表明这些物种实际上是复合种，并且其中一些新物种可能具有宿主特异性。本文将批判性地审视这些寄生虫人畜共患传播的证据。
