Abstract: Thelaziacallipaeda, T. californiensis and T. gulosa are three causative agents of human thelaziasis. Most of the reported cases were caused by T. callipaeda, occurring in the old world, particularly in Asian and European countries. T. californiensis and T. gulosa have rarely been reported infecting humans in North America. T. callipaeda has long been called the oriental eye worm, referring to its traditional distribution across eastern and southeastern Asia (i.e., China, Korea, Japan, Indonesia, Thailand, and India) where infection is endemic in animals and humans, usually in poorer rural areas and mainly among children and the elderly. The identification of the parasite was mainly based on the characteristics of oral and genital organs. In Asia and Europe, vectors for this nematode are male Phorticaokadai and P. variegata drosophilids respectively, which feed on ocular secretions of hosts and transmit infective stage larvae to domestic and wild carnivores, lagomorphs, and humans. China probably has the largest number of cases with thelaziasis in the world, and lots of cases have been existed in other Asian countries such as Japan and Korea. Although a few of human cases have been reported, there were high infection rates of wild animals and domesticated dogs and cats in most of European countries. Based on the cox1 gene, a total of 21 haplotypes were identified in the samples from worldwide, in which, one circulated only in European countries (h1), while the other 20 haplotypes were distributed in Korea, Japan and China. In general, the Chinese clinical isolates of T. callipaeda expressed high genetic diversity. The population differences between Europe and Asian countries were greater than those among China, Korea and Japan. The T. callipaeda populations from Europe and Asia should be divided into two separate sub?populations. These two groups started to diverge during the middle Pleistocene. 　

Key words: Thelaziacallipaeda, Thelaziasis, Thelazia, Etiology, Epidemiology, Genetic diversity

摘要： 目前，有3种吸吮线虫可感染人体导致吸吮线虫病：结膜吸吮线虫（Thelaziacallipaeda）、加利福尼亚吸吮线虫（T. californiensis）和大口吸吮线虫（T. gulosa）。结膜吸吮线虫主要分布在欧洲和亚洲地区，加利福尼亚吸吮线虫和大口吸吮线虫主要分布在北美地区。结膜吸吮线虫病主要流行于经济卫生条件较差的地区且当地有大量的家养或野生动物感染，虫种鉴定主要依赖口及生殖器官的特征，果蝇为其传播媒介，在亚洲是冈田绕眼果蝇（Phorticaokadai），在欧洲传播媒介则为变色伏绕眼果蝇（P. variegate）。我国是世界上结膜吸吮线虫病例数最多的国家，其他亚洲国家如韩国、日本等也有大量病例报道；欧洲地区病例较少，但在多数国家感染该虫的野生及家养动物较普遍。基于cox1基因，在全球范围内共鉴定出21个单倍型，其中单倍型1（Haplotype1）仅在欧洲不同地区不同宿主之间循环，其他20个单倍型分布于东亚国家（中、韩、日），又以我国的结膜吸吮线虫遗传多态性水平最高。遗传差异性分析表明，亚洲结膜吸吮线虫类群与欧洲类群存在长期地理隔离，且这两个类群在更新世中期已经开始分化。

关键词: 结膜吸吮线虫, 吸允线虫病, 吸允属, 病原学, 流行病学, 遗传多态性