我国间日疟原虫基因型种群结构及其地理分布

Investigation on Genotype Constitution of Different Plasmodium vivax Isolates and its Geographical Distribution in China

目的 用分子技术调查中国间日疟原虫种群结构与地理分布。 方法 用滤纸血滴法采集我国 10个省 (自治区 )间日疟现症病人血样 ,用套式 、半套式 等位特异PCR基因分型法鉴定其型、族归属及其CSP基因型 ,并作流行病学统计分析。 结果 在 384个间日疟原虫分离株中 ,检出温带族 2 5 8株 ,分为 14个不同的(等位变异 )基因型 ,遍布全国各省 ,其中主带≤ 731bp的基因型仅见于南方 5省 ;热带族 79株 ,分为 5个不同基因型 ,分布于北纬 2 5°以南的 5个省 (自治区 ) ;PV 2型 16株 ,包括 2个基因型 ;另 33个分离株为不同型(族 )或不同基因型虫株的重复 (混合 )感染。 结论 目前我国北纬 2 5°以北各省是单一温带族间日疟原虫分布区 ,北纬 2 5°以南地区是温带族与热带族间日疟原虫重叠分布区 ,其中海南和云南两省局部地区同时尚存在PV 2型 ;温带族内存在地理分布明显不同的 2个基因类群。

Objective To investigate the population constitution and geographical distribution of Plasmodium vivax in China using molecular technique. Methods Blood spot filter paper samples with related epidemiological data were collected from vivax malaria patients living in malarious area of 10 provinces (autonomous region) in China. Semi nested or nested allelic specific PCR genotyping method was used to identify CSP genotypes, families and types of Plasmodium vivax of each isolate from these patients. Results Of 384 field isolates of Plasmodium vivax , 258 temperate zone family strains were identified,including 14 allelic variant genotypes spreading among 10 sampling provinces; allelic variants sized less than 731 bp were only seen in 5 provinces in southern China; 79 tropical zone family strains including 5 genotypes were also distributed in 5 provinces of southern China south to 25° N.lat; and 14 PV Type 2 strains including 2 genotypes were found in some areas of Hainan and Yunnan Provinces. In addition, 33 isolates from genotype\|mixed infections were revealed. Conclusion At present, area north to 25° N.lat. of the country is the sole area prevalent for Plasmodium vivax family strains of temperate zone;there is overlapping distribution of P\^v . of temperate zone family and tropical zone family of this parasite in the southern China south to 25° N.lat; where the most complex isolate constitution is in Yunnan and Hainan Provinces, and PV Type 2 strains have been found in some areas of the two provinces.Besides, there were 2 groups of genotype with distinct geographic distribution feature within the temperate zone family.