Research progress on sensitivity, resistance and mechanism of plague infected animals to Yersinia pestis / 中华地方病学杂志

The sensitivity and resistance of host animals to Yersinia pestis are different among species and regions, and the indicator animals have natural resistance to Yersinia pestis. This article reviews the research progress on sensitivity, resistance and mechanism of plague infected animals to Yersinia pestis, in order to help improve the ecological research of plague and the prevention and control of plague.

Correlation between host animal and hemorrhagic fever with renal syndrome in Qingdao City of Shandong Province from 2011 to 2015 / 中华地方病学杂志

Objective To investigate the influence of host animals on epidemics of hemorrhagic fever with renal syndrome (HFRS) so as to provide a basis for effective control of HFRS.Methods From the national infectious disease network direct reporting system,the incidence of HFRS cases diagnosed by direct diagnosis of medical institutions in Qingdao was collected from 2011-2015.We captured rats indoor and outdoor by night trapping method quarterly and calculated the capture rates from 2011-2015 in Qingdao areas.The incidence of HFRS in different regions and the change of seasonal growth,the distribution of host animals,the characteristics and distribution of animals,and the seasonal variation of dominant species were analyzed and a database was set up and statistic analysis was conducted by SPSS 13.0.Results The peak incidence rate of HFRS in Qingdao areas occurred in 2012 (3.54/100 000) and presented a decrease trend year by year (x2 =64.15,P ＜ 0.05),but there were different characteristics among the epidemic areas,and lowest in 2015 (1.68/100 000).And the peak presented a two-peak pattern which was mainly an autumn peak and a gentle peak in late spring and early summer.The epidemics were gradually decreased from the rural areas to the urban fringes and then the urban areas.The seasonal variation was disappeared gradually.There was a heavy epidemic intensity in areas with a high capture rate and a complex type of host animals.The epidemic peak was in consistence with the distribution of rats.Capture rates were different among the epidemic areas.The capture rate in Jiaonan was the highest [5.32％(2 886/54 287)] and lowest in Pingdu [1.77％ (258/14 584)].The mean (x2 =820.39,P ＜ 0.05) and annual capture rates (x22011-2015 =32.61,356.24,233.07,129.33,33.42,all P ＜ 0.05) among epidemic areas were different.In the third quarter the accumulated capture rate was the highest [4.69％ (1 187/25 301)].In total 8 kinds of host animals were captured and the dominant species were brown rat [30.27％ (1 235/4 080)],house mouse[29.75％ (1 214/4 080)] and striped field mouse [16.25％ (663/4 080)].Conclusions The epidemic intensity of HFRS is related to the densities and the types of host animals.The gradually decreased epidemic pattern from the rural areas to the urban fringes and then the urban areas may be related to urbanization and improved health behaviors.

Diversity and distribution of host animal species of hantavirus and risk to human health in Jiuhua mountain area, China / 生物医学与环境科学（英文）

<p><b>OBJECTIVE</b>To investigate the diversity and the distribution of host animal species of hantavirus and the effect on human health in Jiuhua Mountain area, China.</p><p><b>METHODS</b>The host animal species of hantavirus was surveyed by using the trap method and the species diversity was evaluated by using the Simpson, Shannon-Weaner, and Pielou indices. Hantavirus antigens or antibodies in lung and blood samples of all the captured host animals were detected by direct or indirect immunofluorescence.</p><p><b>RESULTS</b>Nine animal species of hantavirus were distributed in the forest ecosystem of Jiuhua Mountain. Of these, Niviventer confucianus and Apodemus agrarius were predominant, and N. confucianus, Rattus norvegicus, and Mus musculus had relatively large niche breadth index values. The host animals in the eastern and western mountain regions shared similar biodiversity index characteristics, predominant species, and species structures. Hantavirus was detected in 5 host animal species in Jiuhua Mountain area, the carriage rate of hantavirus was 6.03%. The average density of host animals in forest areas of the mountainous area was only 2.20%, and the virus infection rate in the healthy population was 2.33%.</p><p><b>CONCLUSION</b>The circulation of hantavirus was low in the forest areas of Jiuhua Mountain and did not pose a threat to human health.</p>

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

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.

Survey on host animal and molecular epidemiology of hantavirus in Chuxiong prefecture, Yunnan province / 中华流行病学杂志

Objective To determine the hosts of hantavirus (HV) and its molecular epidemiological characteristics, to provide evidence for prevention and control on hemorrhagic fever with renal syndrome (HFRS). Methods Rodents were captured by a special trap within the residential area. The antigens of HV in lung tissues were detected by direct immuno-fluorescence assay (DFA). Nucleotide sequences of HV were amplified by RT-PCR with HV genotype-specific primer. The amplified genes were then sequenced. Phylogenetic tree were built on nucleotide sequence with Clusta1X 1.83 software. Results 1421 rodents were captured and classified into 8 species of 4 Genera in the epidemic area within 10 counties of Chuxiong prefecture, Yunnan province, between 2005 and 2006. Out of the 1421 rodents, 1056 (74.31%) of them were Rattus norvegicas and 280 (19.70%) belonged to Rattus flavipectus. The antigens of HV were detected by DFA in lung tissues and the total positive rate of HV was 5.15% (53/ 1029). After applying the sequencing nucleotide method to the 53 positive specimens, data showed that 21 specimens were positive and all of them belonged to Seoul type ( 15 samples were from Rattus norvegicus, 4 samples Rattasflavipectas, 2 samples Rattus nitidas). The partial S segments from 12 specimens were sequenced which appeared homologic with R22, L99 and HLD65 from GenBank in relatively high level (87.1%-99.7%). When compared to 76-118 strain of Hantaan type, their homologic degree was only 64.4%-69.1%. Results from Phylogenetic analysis showed that 12 specimens belonged to Seoul type. As for their homology, they were significantly similar to Seoul type and could be tentatively divided into two subtypes S1 and S3. Conclusion It was confirmed that the Seoul type virus, as HFRS' s pathogenetic agent mainly carried by rats, prevailed widely in Chuxiong prefecture. Owing to the local ecological environment, we also noticed the characteristics of different HV subtypes among Seoul type.