几种新现人体隐孢子虫种和基因型流行现状

Epidemiology status of some new emerging Cryptosporidium species and genotypes in humans

隐孢子虫是一种寄生于宿主胃肠道上皮细胞内的原虫。人感染后,免疫功能正常者,常引起自限性腹泻;但在高危人群(如儿童、老人和免疫缺陷者等)中可发生严重腹泻和肠外感染,尤其是艾滋病患者。目前,隐孢子虫的分子流行病学研究已鉴定了30个有效种和40多种基因型,其中21个隐孢子虫种和基因型在人体发现。人体隐孢子虫病多数由人隐孢子虫(C.hominis)和微小隐孢子虫(C.parvum)引起。火鸡隐孢子虫(C.meleagridis)、泛在隐孢子虫(C.ubiquitum)、猫隐孢子虫(C.felis)和犬隐孢子虫(C.canis)引起的隐孢子虫病例也逐渐增多。除此之外,随着人体隐孢子虫病分子流行病学数据的增加,在人体内鉴定到一些新的隐孢子虫和基因型。特对上述新现的人体隐孢子虫种和基因型的流行现状进行综述。

Cryptosporidium spp. are protozoan parasites that infect the epithelial cells of the gstrointestinal tract of hosts. In humans, cryptosporidiosis is usually a self-limiting infection in immunoeompetent individuals, but severe diarrhea and dissemination to extra-intestinal sites can occur in high-risk individuals, such as the very young, the elderly,immunedeficiency in- dividuals, particularly in HIV-positive patients. So far, molecular epidemiologieal data have confirmed the presence of 30 species and over 40 genotypes with genus Cryptosporidiurn, with 21 species and genotypes being found in humans. The majority of human cryptosporidiosis cases are responsible for C. horninis and C. parvurn. Human cases caused by C. meleagridis, C. ubiquiturn, C. fells and C. canis have been increasing. Besides that, with data accumulation of molecular epidemiology of human cryptosporidiosis, some more Cryptosporidiurn species and genotypes were newly identified in humans. This paper mainly reviews epidemiology status of these new emerging Cryptosporidium species and genotypes in humans.