中国滇西家鼠鼠疫宿主及媒介群落结构差异的流行病学意义

Study on the epidemiological significance related to community-structural difference of the rat plague host and vectors in Western Yunnan, China

目的探讨云南省德宏、保山两个相邻家鼠鼠疫疫源地小哺乳动物及黄胸鼠体表蚤类群落组成与物种多样性差异的鼠疫流行病学意义。方法用群落内的优势种构成比、多样性及聚类分析，对1982—1996年的调查资料进行分析。结果两地区捕获的27种75490只小哺乳动物可划分为3个群落：群落Ⅰ[瑞丽居民区黄胸鼠（54．41％）＋大臭鼢（33．37％）]；群落Ⅱ[陇川、盈江居民区黄胸鼠（62．99％）＋大臭嗣（23．25％）＋小家鼠（10．06％）]；群落Ⅲ[保山居民区黄胸鼠（48．07％）＋大臭嗣（19．56％）＋灰麝鼢（14．37％）]。两地区所捕获黄胸鼠体表蚤类11种61122只划分为3个群落：群落i[瑞丽居民区印鼠客蚤（83．51％）＋野韧棒蚤（13．86％）]；群落ii[陇川、盈江居民区印鼠客蚤（74．42％）＋缓慢细蚤（22．94％）]；群落iii[保山居民区缓慢细蚤（70．62％）＋印鼠客蚤（22．70％）]。德宏地区在10个年份内，从7种宿主和5种媒介动物中分离到鼠疫菌1471株；保山地区仅在1个年份，从1种宿主和2种媒介动物中分离到鼠疫菌36株。另外德宏地区黄胸鼠、印鼠客蚤的构成比均较高，分别为58．70％和78．97％；宿主、媒介群落的物种多样性指数都较低，分别为1．010和0．625。而保山地区则与之相反，黄胸鼠和印鼠客蚤的构成比都较低，分别为48．07％和22．70％；宿主、媒介群落的物种多样性指数较高，分别为1．471和0．829。致使蚤类群落i-iii的主要优势蚤种，由印鼠客蚤转为缓慢细蚤。结论保山地区宿主、媒介群落物种多样性指数高，而主要宿主、媒介的构成比低，是降低该地区鼠疫流行的重要原因。

Objective To study the epidemiological significance of community-structural difference regarding both small mammal and flea communities on Rattus flavipectus in Dehong and Baoshan areas, Yunnan province, during 1982 to 1996. Methods Methodologies as cluster analysis, communities dominated constitution and species diversity were used for data analysis. Results 75 490 small mammals of 27 species could be divided into three types： I ~ Ruili habitat-communities dominated by R.flavipectus （54.41%） and Suncusmurinus （33.37%）; Ⅱ. Longchuan and Yingjiang habitat-communities dominated by R. flavipectus （62.99 % ）, S. murinus （23.25 % ） and Mus rnusculus （ 10.06 % ） ; Ⅲ . Baoshan habitat-community dominated by R. flavipectus （ 48.07% ）, S. murinus （ 19.56% ） and Crocidura attenuats （14.37%）. The captured 61 122 fleas of 11 species on R.flavipectus could be divided into three types： i . Ruili habitat-communities dominated by Xenopsylla cheopis （83.51% ）and Lentistivsliusferinus （13.86%）; ii. Longchuan and Yingjiang habitats X. cheopis （74.42%） and L.segnis （22.94%）; Ⅲ. Baoshan habitat-communities dominated by L.segnis （70.62%） and X. cheopis （22.70%）. There had been 1471 strains of Y. pestis isolated from the hosts of 7 species and vectors of 5 species in Dehong areas for the ten year period. 36 strains of Y. pestis were isolated from host of one species and vectors of 2 species in Baoshan area for ten years. The constitution ratio of R. flavipectus and X. cheopis was higher in Dehong area with average as 58.70 % and 78.97 % respectively. However, the diversities of species among host and vector communities were low, with average as 1. 010 and 0. 625. On the contrary, the constitution ratios of R.JTavipectus and X. cheopis were lower in Baoshan area, with an average as 48.07 % and 22.70 % respectively but the diversities of species among host and vector community were higher with the averages as 1.471 and 0.829 respectively. The main dominative flea species from ‘ group ii ’ to ‘ group iii＇ in the flea community had changed from X. cheopis to L. segnis. Conclusion The species diversity index of host and vector community was higher in Baoshan area, while the constitution ratio of main host and vector community was lower. This findings seemed to be the important factor of the decrease of plague prevalence in Baoshan area.