Research On The Spatial Distribution Pattern Of The Rodent And Flea Species Diversity Commensal Rodent Plague In Southern Yunnan Province

Objective To investigate the community structure, diversity and spatial distributionpattern of rats and its ectoparasitic fleas in rat plague foci of Southwest YunnanMountain, explore the characteristic and frequency of host animals and rodent foci indifferent media landscape, and reveal the distribution pattern of the relationshipbetween space and plagueMethods Parts of counties in Southwest Yunnan province including Xishuangbanna,Lincang and Puer cities were selected as investigated site, and animals and itsectoparasitic flea among different landscape in the three districts were considered asthe research species. Biological investigations were conducted regularly and theobtained data was processed using simple statistical methods, the characteristic,frequency, diversity, spatial distribution and the factors of geographical environmentof rats and their ectoparasitic fleas were evaluated.Results (1) A total of719small mammals were trapped in the three cities, which wereclassified into20species,12genus and6families in3sections. Among719smallhosts mammal, Rattus tanezumi (40.61%) and Rattus yunnanensis (15.16%) were theabsolute dominant species in the house rat plague focus. Moreover, a total of229ectoparasitic fleas were trapped and classified into14species,11genus and5families.Xenopsylla cheopis (57.21%) and Lushui ctenophthalmus (17.03%) were the absolutedominant species.(2) There were significant differences in the species of these smallhost mammals and their ectoparasitic fleas among different landscape.Species richness is the most in the forest region and following is the farming area andthe least is the living district.For instance, the amounts of Rattus tanezumi captured inthe farming areas were more than that captured in the forest regions and the living districts (P<0.05). Furthermore, the captured Xenopsylla cheopis among living areaswere more than that among the forest and farming areas (P<0.05).(3) The trend ofspecies richness and diversity both showed a single peak distribution pattern, just asthe profile of first increase and then decrease. The maximum is included in the rangeof1000～1500m. Meanwhile, the irregular distribution was seen for the change inthe ectoparasitic fleas among different altitudinal gradient. The elevation of1000～15000m was suitable for the survival of both small mammals and these ectoparasiticfleas.(4) The positive associations between density and proportion of the small hostmammals were observed. Also, the significant associations of the Shannon-Wienerindex with richness, homogeneity and coverage were seen among the ectoparasiticfleas. Conclusions There are distinct difference in the small host mammals and theirectoparasitic fleas between different landscape areas. The changes in the small hostmammals and their ectoparasitic fleas are affected by the altitudinal gradient. Theenvironment of1000～1500m elevation is feasible for the living of small hostmammals and their ectoparasitic fleas. Important environmental factors such aslongitude, latitude, and altitude play a substantial role on the distribution patterns ofindoor hosts animal among various focus, therefore directly impact on modes of theprevalence and transmission of plague. Small mammal and the parasitic fleas ofdifferent space distribution pattern determines the mice south yunnan plagueprevalence and distribution of the trend.