RESUMO
Objective@#To investigate whether plague phages were present in the indicator animals of plague foci in Yunnan Province, and to explore their epidemiological significance.@*Methods@#Anus swabs were collected from indicator animals (dogs or cats) of the 41 plague affected villages in 26 towns of 10 cities (counties, districts) of Yunnan plague foci from November of 2015 to March of 2018. The Yersinia pestis phages were isolated by plague vaccine strain EV76. The isolation of plague phages from different plague foci, the isolation of plague phages from different canine species (cats), the polymorphism of plaque and the host spectrum of phages were analyzed.@*Results@#A total of 1 014 indicator animals (1 003 dogs and 11 cats) were studied, and 102 of plague phages were isolated. In the 10 cities (counties, districts), plague phages were only not isolated from Lancang County, and the plague phages were isolated from the other 9 cities (counties, districts). The separation rates from high to low were as follows: Yiliang County (21.00%, 21/100), Menghai County (19.23%, 25/130), Yuanjiang County (11.63%, 10/86), Midu County (11.50%, 13/113), Wenshan County (10.10%, 10/99), Mile Country (7.07%, 7/99), Lianghe County (6.67%, 7/105), Baoshan Longyang District (4.90%, 5/102) and Gengma County (3.81%, 4/105). Of the 102 plague phages, 75 were isolated from the native dogs (Chinese pastoral dogs, 9.32%, 75/805), 20 from the pug dogs (13.70%, 20/146), 5 from the wolf dogs (17.24%, 5/29), 1 from Samoye (1/4) and 1 from Alaska dog (1/2). The plaque of the phage was divided by five appearance of complete lysis (the plate was clear), large (2.5-4.0 mm), big (1.5-< 2.5 mm), middle (0.5-< 1.5 mm) and small (< 0.5 mm). The representative phages were all of the Myoviridae family. Most of the phages could lysis the strains of Yersinia pestis, and some phages could lysis Shigella and type 5 Yersinia pseudotuberculosis (PST5).@*Conclusion@#The plague phages are present in the plague foci of Yunnan, and the phages are polymorphic.
RESUMO
Objective To investigate whether plague phages were present in the indicator animals of plague foci in Yunnan Province,and to explore their epidemiological significance.Methods Anus swabs were collected from indicator animals (dogs or cats) of the 41 plague affected villages in 26 towns of 10 cities (counties,districts) of Yunnan plague foci from November of 2015 to March of 2018.The Yersinia pestis phages were isolated by plague vaccine strain EV76.The isolation of plague phages from different plague foci,the isolation of plague phages from different canine species (cats),the polymorphism of plaque and the host spectrum of phages were analyzed.Results A total of 1 014 indicator animals (1 003 dogs and 11 cats) were studied,and 102 of plague phages were isolated.In the 10 cities (counties,districts),plague phages were only not isolated from Lancang County,and the plague phages were isolated from the other 9 cities (counties,districts).The separation rates from high to low were as follows:Yiliang County (21.00％,21/100),Menghai County (19.23％,25/130),Yuanjiang County (11.63％,10/86),Midu County (11.50％,13/113),Wenshan County (10.10％,10/99),Mile Country (7.07％,7/99),Lianghe County (6.67％,7/105),Baoshan Longyang District (4.90％,5/102) and Gengma County (3.81％,4/105).Of the 102 plague phages,75 were isolated from the native dogs (Chinese pastoral dogs,9.32％,75/805),20 from the pug dogs (13.70％,20/146),5 from the wolf dogs (17.24％,5/29),1 from Samoye (1/4) and 1 from Alaska dog (1/2).The plaque of the phage was divided by five appearance of complete lysis (the plate was clear),large (2.5-4.0 mm),big (1.5-＜ 2.5 mm),middle (0.5-＜ 1.5 mm) and small (＜ 0.5 mm).The representative phages were all of the Myoviridae family.Most of the phages could lysis the strains of Yersinia pestis,and some phages could lysis Shigella and type 5 Yersinia pseudotuberculosis (PST5).Conclusion The plague phages are present in the plague foci of Yunnan,and the phages are polymorphic.
RESUMO
Objective To study on the effect of indicator animals in plague surveillance throngh detecting F1 antibody against Yersiniapestis(Y.pestis)in indicator animals in wild rat plague foci,provide scientific evidence for plague control and determining the range of epidemic area.Methods According to investigation scheme of wild rodents plagne foci in Yunnan Province,indicator animals Canis familiarils and Felis catu(C.familiarils and F.catus)related to the plague were investigated in 75 villages,14 township and 10 counties around Yulong County,and living rodents were captured by cage,sera of indicator animals and rodents relevant to plague were simultaneously collected and detected for F1 antibody against Y.pestis using indirect hemagglutination(IHA).Results Seropositivity rate of indicator animals were 6.76%(202/2987),being 24.69% in C.familiaris and 24.69% in F.catus,there were statistical significance(X2＝87.32,P＜0.01)between C familiaris and F catus,the latter beingmore than the former.But F1 antibody of rodents sera were not detected,its seropositivity rate was zero.there was a statistical significance(P＜0.01)between indicator animals and rodents.Conclusions Through serocpidemiological survey of indicator animals,new wild rat plague natural focus has been confirmed in YuLong County and Gucheng District in LiJiang City,therefore,serocpidemiological surveillance of indicator animals is very important for plague control and prevention.