Attwood Stephen W, Huo Guan-Nan, Qiu Jian-Wen
State Key Laboratory of Biotherapy, West China Hospital, West China Medical School, Sichuan University, Chengdu, People's Republic of China; Department of Life Sciences, The Natural History Museum, London, United Kingdom.
State Key Laboratory of Biotherapy, West China Hospital, West China Medical School, Sichuan University, Chengdu, People's Republic of China.
Acta Trop. 2015 Jan;141(Pt B):258-70. doi: 10.1016/j.actatropica.2014.04.032. Epub 2014 May 5.
In 1973 planorbid snails then identified as Biomphalaria straminea were discovered in Hong Kong, China. It was assumed that these snails had been introduced to Hong Kong via the import of tropical fish by air from South America. In 2012 Biomphalaria were found for the first time in Guangdong Province, China. In view of the renewed interest in these invasive snails, a morphological and DNA-sequence based phylogenetic study was undertaken for seven populations of Biomphalaria snails collected in Guangdong. Morphologically and phylogenetically, five of the populations clustered more closely with Biomphalaria kuhniana than with B. straminea. Levels of genetic diversity among the populations were about half those of autochthonous populations in Brazil, the phylogenetic relationships did not correlate with a radiation from any one international port in China, and different lineages appeared associated with different ports. Consequently in explaining the current distribution of the snails, multiple colonization events, each establishing a new local snail population near to maritime international container ports, were considered more likely than the spread of snails from Hong Kong to China. The displacement of B. straminea by B. kuhniana in Guangdong is considered as an explanation for the habitat changes observed among the snails between Hong Kong in the 1980s and the present. The conclusions of the study are that any risk of Schistosoma mansoni transmission in China is more likely to come from parasite importation in the intramolluscan stage, than from transmission by migrant workers from South America or Africa. In addition, although likely to be rare, sporadic outbreaks of imported schistosomiasis (caused by invading infected snails) could be a threat to public health in the vicinity of International container ports (not only in Guangdong Province). Further work is called for to investigate further the presence of B. kuhniana and its potential interactions with B. straminea (the former is thought to be incompatible with S. mansoni), and the responses of Chinese Biomphalaria to potential competitors such as Thiaridae. The current expansion of container ports in Brazil and Venezuela, and the increase in trade with China, is likely to accentuate any current risk of imported schistosomiasis, and surveillance around ports in China, together with further research, are necessary.
1973年，在中国香港发现了当时被鉴定为淡黄小泡螺的扁卷螺。据推测，这些螺是通过从南美洲空运进口热带鱼而被引入香港的。2012年，在中国广东省首次发现了小泡螺属。鉴于对这些入侵螺的兴趣再度兴起，对在广东采集的7个小泡螺属螺种群进行了基于形态学和DNA序列的系统发育研究。在形态学和系统发育方面，其中5个种群与库氏小泡螺的聚类关系比与淡黄小泡螺的更密切。这些种群的遗传多样性水平约为巴西本地种群的一半，系统发育关系与中国任何一个国际港口的辐射情况均不相关，且不同谱系似乎与不同港口有关。因此，在解释这些螺目前的分布情况时，认为多次定殖事件（每次在国际海运集装箱港口附近建立一个新的本地螺种群）比螺从香港扩散到中国更有可能。广东库氏小泡螺取代淡黄小泡螺被认为是对20世纪80年代至今香港螺类栖息地变化的一种解释。该研究的结论是，中国曼氏血吸虫传播的任何风险更可能来自于软体动物体内阶段的寄生虫输入，而非来自南美洲或非洲的外来务工人员传播。此外，尽管可能很少见，但输入性血吸虫病（由入侵的感染螺引起）的零星爆发可能对国际集装箱港口附近（不仅是广东省）的公众健康构成威胁。需要进一步开展工作，以进一步调查库氏小泡螺的存在及其与淡黄小泡螺的潜在相互作用（前者被认为与曼氏血吸虫不相容），以及中国小泡螺属对诸如蜒螺科等潜在竞争者的反应。巴西和委内瑞拉目前集装箱港口的扩张以及与中国贸易的增加，可能会加剧当前输入性血吸虫病的任何风险，因此在中国港口周围进行监测以及进一步开展研究是必要的。
