Geographical distribution of host animals of plague in residential areas in Yunnan Province / 中华地方病学杂志

ABSTRACT

Objective To investigate the geographical distribution of plague host animals in residential areas and the association between plague and its distribution pattern in Yunnan Province.Methods A systematic investigation on fauna and community ecology of rodents was carried out in residential areas of 17 counties(cities) of Yunnan Province,southwestern China with different longitude,latitude and elevation from May 2007 to November 2012.The characteristics of the spatial distribution of flea communities along environmental gradients were analyzed using community structure indexes.Results A total of 390 small mammals were trapped in seventeen counties (cities),and the mammals were classified into 11 species and 7 genus in 4 families.Among all small host mammals,Rattus tanezumi,Rattus nitidus and Rattus norvegicus were dominant species of host animals in residential areas,accounting for 33.85％ (132/390),20.77％ (81/390) and 16.92％ (66/390),respectively.The horizontal distribution of rodents showed that Rattus tanezumi was the widest species in residential areas,which was found at the longitude 98°-105°,followed by Rattus norvegicus,Rattus yunnanensis and Mus musculus.The vertical and latitudinal distributions of rodents were similar in residential areas.Rattus tanezumi was also the widest distributed species,which was observed at the latitude 21°-＜ 28°N and at the altitude 500-＜ 3 500 m; the constituent of Rattus tanezumi showed similar trends of leaning peak curves,first gradually increasing and then decreasing with the increase of latitude and elevation; Rattus tanezumi gradually changed into Rattus nitidus and Apodemus chevrieri,et al.The richness spatial distribution patterns of host animals showed similar trends of leaning peak curves which gradually increased and then decreased with increasing of longitude and latitude; the highest richness was observed at the longitude 98°-＜ 101°E and at the latitude 23°-＜ 28°N.While,the richness spatial d istribution patterns of host animals were relatively poor in the low or the high altitude range.The highest richness was observed at the altitude between 1 000-＜ 1 500 m and 2 000-＜ 2 500 m.Conclusions All spatial patterns of indoor host animals have shown an aggregated spatial distribution in Yunnan Province.Moreover,important environmental factors such as longitude,latitude,and altitude play a substantial role on the distribution patterns of indoor host animals among various focus,therefore directly impact on the modes of prevalence and transmission of plague.