Objective To analyze the spatial distribution patterns of rodent community and the risk factors of disease transmission in natural foci of Xiji County,Ningxia,in order to provide a scientific basis for disease control and prevention.Methods Rodents were captured at different habitats in different latitudes which were selected with a stratified sampling method in 2012-2013.Capture rate of different rodent species and spatial distribution patterns of the animal community were analyzed.Antigen and antibody of hantavirus were detected in lung tissue and blood of the rodents with immunofluorescence and enzyme-linked immunosorbent assay (ELISA),respectively.Serum F1 antibody of Yersinia pestis (Y.pestis) was detected with indirect hemagglutination test and Y.pestis from liver and spleen tissue was cultured in vitro.Results Fourteen species of rodents were captured,belonging to 2 orders,7 families and 9 genera.Among them,ground squirrels and wood mouse were dominant species,accounted for 49.56％ (112/226) and 34.51％ (78/226) of the community,respectively.Infections of hantavirus and Y.pestis were not found in the rodent's community.Conclusion With the improvement of ecological environment in Xiji County,the spatial distribution patterns of rodent community is changing; the risk of zoonotic plague is reduced,but the risk of hemorrhagic fever with renal syndrome is being.

ABSTRACT:To improve the ability of correct classification and identification of rodents in different kinds of foci of zoonosis in Ningxia Hui Autonomous Region in China ,rodents samples from different habitats of Ningxia were collected .Sequences of COI gene were amplified and sequenced from 154 samples .Based on these sequences ,the pairwise genetic distance were calcu‐lated ,and a Neighbor Joining tree were constructed .According to the NJ tree ,20 clusters with high bootstrap support were found from 19 morphological species .The striped dwarf hamsters were divided into two clusters ,which suggested that there were two cryptic species with stripe on the back .The pika from Helan Mountain showed close relationship with Ochotona pal‐lasi ,and the genetic distance was as low as 3 .6% .Results show that DNA barcodes could be used to accurately identify speci‐mens of rodents and correct morphological identification errors .It could discover appearance indistinguishable implied species and could better study the classification and evolution of rodents .

Objective:To analyze the influence and related lag effects of meteorological factors on scrub typhus (ST) in southwestern Yunnan, to provide a reference for the corresponding prevention and treatment measures.Methods:Data on ST and meteorology in Yunnan province from 2007 to 2018 were collected. A distributed lag nonlinear model was conducted to study the cumulative lag effects of temperature, relative humidity, and rainfall on ST.Results:From 2007-2018, a total of 19 975 ST cases were reported in southwestern Yunnan. Weekly mean temperature, mean relative humidity, and the risk of ST all showed J-shaped curves. The cumulative risk of ST increased with mean temperature >23 ℃, mean relative humidity >80%, and cumulative rainfall between 20 and 60 mm or over 100 mm, weekly. Taking the median value as the reference, higher temperature (22.27 ℃, 23.45 ℃), relative humidity (80.14%, 84.38%) and rainfall (37.17 mm, 74.42 mm) all increased the risk of disease while lower temperature (11.22 ℃,14.83 ℃), relative humidity (53.18%,65.36%) and rainfall (0.00 mm,0.55 mm) showed opposite effects. The temperature-lag effect lasted for 10 and 16 weeks, respectively, with ST's risk the highest during the week of exposure. Humidity-lag effects usually last for 10 and 17 weeks. The lag effect of rainfall lasted for 25 weeks, while the disease's risk was the highest in the 4 th week. Conclusion:Factors as temperature, relative humidity, and precipitation showed nonlinear and lag effects on ST. High temperature, high relative humidity, and an appropriate amount of rainfalls increase the risk of ST. The authorities of public health should implement effective prevention and control measures according to meteorological conditions.