Objective:To investigate the host and vector composition of pestis and the epidemic situation of pestis among animals in the border port areas of Longchuan County, Yunnan Province.Methods:In September 2022, a survey was conducted on rodents and their surface parasitic fleas in the border port areas of Longchuan County, according to three habitat types: residential areas, agricultural areas, and forest-shrubbery areas. Samples of murine animals organs and their surface parasitic fleas were collected for isolation and identification of Yersinia pestis. Blood samples of plague indicating animals, such as murine animals, dogs and cats were collected, and serum plague F1 antibody was detected by indirect hemagglutination assay. Meanwhile, a retrospective investigation was conducted on the occurrence of self dead rats, sick rats, and suspected cases in the local area from 2018 to 2022 through interviews with farmers. Results:A total of 168 murine animals belonging to 3 orders, 5 families, 10 genera, and 11 species were captured in three habitats in Longchuan County. Among them, the capture rate in residential areas was 5.00% (30/600), with Rattus tanezumi and Suncus murinus as dominant species, with a composition ratio of 50.00% (15/30). The capture rate in agricultural areas was 9.67% (122/1 262), with Rattus tanezumi and Suncus murinus as dominant species, with a composition ratio of 50.82% (62/122) and 44.26% (54/122), respectively. The capture rate in the forest-shrubbery areas was 6.25% (16/256), with Hylomys suillus and Eothenomys eleusis as dominant species, with a composition ratio of 37.50% (6/16) and 31.25% (5/16), respectively. Among the captured murine animals, 20 individuals carried 52 parasitic fleas, belonging to 2 species of 2 genera and 2 families. The total flea infection rate was 11.90% (20/168), and the total flea index was 0.31 (52/168). The dominant specie was Xenopsylla cheopis (90.38%, 47/52). The flea infection rate in residential areas was 33.33% (10/30), and the flea index was 1.23 (37/30). The flea infection rate in agricultural areas was 7.38% (9/122), and the flea index was 0.11 (14/122). The flea infection rate in the forest-shrubbery areas was 6.25% (1/16), and the flea index was 0.06 (1/16). The samples of murine animals and their parasitic fleas obtained were isolated and cultured by Yersinia pestis, and the results were negative. A total of 144 serum samples from murine animals, dogs and cats were separated, and no F1 antibody against pestis was detected. According to interviews and investigations, no abnormal situations such as a large number of self dead rats, sick rats, and suspected cases were found from 2018 to 2022. Conclusions:No plague epidemic has been found in the border port areas of Longchuan County recently. The main host of plague, Rattus tanezumi, and the main vector, Xenopsylla cheopis, remain the dominant species in this area.

Objective:To investigate the host and vector composition of pestis and the epidemic situation of pestis among animals in the border port areas of Longchuan County, Yunnan Province.Methods:In September 2022, a survey was conducted on rodents and their surface parasitic fleas in the border port areas of Longchuan County, according to three habitat types: residential areas, agricultural areas, and forest-shrubbery areas. Samples of murine animals organs and their surface parasitic fleas were collected for isolation and identification of Yersinia pestis. Blood samples of plague indicating animals, such as murine animals, dogs and cats were collected, and serum plague F1 antibody was detected by indirect hemagglutination assay. Meanwhile, a retrospective investigation was conducted on the occurrence of self dead rats, sick rats, and suspected cases in the local area from 2018 to 2022 through interviews with farmers. Results:A total of 168 murine animals belonging to 3 orders, 5 families, 10 genera, and 11 species were captured in three habitats in Longchuan County. Among them, the capture rate in residential areas was 5.00% (30/600), with Rattus tanezumi and Suncus murinus as dominant species, with a composition ratio of 50.00% (15/30). The capture rate in agricultural areas was 9.67% (122/1 262), with Rattus tanezumi and Suncus murinus as dominant species, with a composition ratio of 50.82% (62/122) and 44.26% (54/122), respectively. The capture rate in the forest-shrubbery areas was 6.25% (16/256), with Hylomys suillus and Eothenomys eleusis as dominant species, with a composition ratio of 37.50% (6/16) and 31.25% (5/16), respectively. Among the captured murine animals, 20 individuals carried 52 parasitic fleas, belonging to 2 species of 2 genera and 2 families. The total flea infection rate was 11.90% (20/168), and the total flea index was 0.31 (52/168). The dominant specie was Xenopsylla cheopis (90.38%, 47/52). The flea infection rate in residential areas was 33.33% (10/30), and the flea index was 1.23 (37/30). The flea infection rate in agricultural areas was 7.38% (9/122), and the flea index was 0.11 (14/122). The flea infection rate in the forest-shrubbery areas was 6.25% (1/16), and the flea index was 0.06 (1/16). The samples of murine animals and their parasitic fleas obtained were isolated and cultured by Yersinia pestis, and the results were negative. A total of 144 serum samples from murine animals, dogs and cats were separated, and no F1 antibody against pestis was detected. According to interviews and investigations, no abnormal situations such as a large number of self dead rats, sick rats, and suspected cases were found from 2018 to 2022. Conclusions:No plague epidemic has been found in the border port areas of Longchuan County recently. The main host of plague, Rattus tanezumi, and the main vector, Xenopsylla cheopis, remain the dominant species in this area.

The specimens of femur from wild-type mice(WT) of 6 months and Hepcidin-knockout(KO) mice of 6 months(iron accumulation model) were obtained for Micro-CT examination. Western blot and co-immunoprecipitation were used to detect the changes of related parameters in Wnt signaling pathway. Compared with wild-type mice, the bone mass in Hepcidin-KO mice was significantly decreased, the binding of β-catenin to FOXO3a increased, and binding of β-catenin to TCF4/TCF7L2 decreased in bone tissue, without significant changes in the expression of β-catenin, TCF4/TCF7L2, and FOXO3a. These results suggest that iron accumulation may affect bone formation through interfering with canonical Wnt/β-catenin signaling pathway, finally leading to osteoporosis.

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.