From 1991 to 2000 the plague in Viet Nam has remarkably controlled. The morbidity and mortality rate decreased from 439.6 patients/year during 1991-1995 to 161.2 patients/year during 1996-2000, the areas affected by plague had been narrowed, only in Gia Lai and Dac Lac provinces. The plague occours throughout the year but concerntrating in period from February to May every year. In the North, R.norvegicus is the main host and R.exulans is the common host at the other areas. The main vector of plague in Viet Nam is X.cheopis. Biological surveillance showed that: Y.pestis has been negative at the provinces and cities in the North for the past years. The possitive rate was different in the rest areas over the times
Plague ; Epidemiology ; Prevention & control

China ; epidemiology ; Humans ; Plague ; epidemiology ; Seroepidemiologic Studies

Backgound: Plague disease is one of three most seriously infectious diseases (plague, yellow fever and cholera disease). In Vietnam, this condition has been obviously controlled. The number of new cases and deaths of plague disease have decreased significantly: from 439.6 patients between 1991 and 1995 to 161.2 patients between 1996 and 2000. However, the disease is still circulating in some areas in the world. Objective: To survey plague disease related factors (rats and fleas) at Noi Bai international airport. Subjects and method: A surveillance to inspect plague disease related factors (rats and fleas) was conducted at Noi Bai international airport, Ha Noi, from January/2006 to December/2006. Results and Conclusion: There were two types of rats: R. flavipectus in majority and R. norvegicus. The enrichment index of the two kinds of rats had increased in April and May. R. flavipectus disposed at flat form T1 and R. norvegicus disposed at store area. The only flea species found at the surveillance site was X.cheopis. Bacterial isolation of 236 specimens of liver and spleen, and ELISA tests of 180 blood samples were performed. All of the specimens were negative to Yersinia pestis. The study suggests that the rat populations at Noi Bai airport have not been infected with Yesinia pestis.
Plague/ epidemiology ; pathology ; Siphonaptera/ pathogenicity ; Rats ;

China ; epidemiology ; Humans ; Plague ; diagnosis ; epidemiology ; Yersinia pestis ; isolation & purification

OBJECTIVETo study the epidemiology of genotyping Yersinia pestis isolated in the fulminant epidemics of human plague in Qinghai province in 2004.

METHODSPrimer pairs targeting the twenty-three different identified regions (DFRs) were designed to detect the presence or deletion of each DFR in 13 strains of Yersinia pestis isolated from the fulminant epidemic of human plague in Qinghai province in 2004.

RESULTSThere were 4 genomovars, i.e. Genomovar 8, 10, 15 and 16 in the 13 strains of Yersinia pestis identified. The genomovar of all the strains of Yersinia pestis isolated from Nangqian county was Genomovar 10. Among the two strains of Yersinia pestis isolated from Wulan county, the genomovar of one strain was Genomovar 8 and the other was Genomovar 10. The genomovars of all the strains of Yersinia pestis isolated from Qilian, Qumalai and Chengduo county belonged to Genomovar 16.

CONCLUSIONIt was demonstrated that the genotyping of Yersinia pestis appeared to be a powerful tool for investigating human plague epidemics.

China ; epidemiology ; Disease Outbreaks ; Genotype ; Humans ; Molecular Epidemiology ; Plague ; epidemiology ; Yersinia pestis ; genetics ; isolation & purification

OBJECTIVETo understand the distribution, fauna, population structure of host animals and their parasitic fleas as well as popular dynamic of animal plague of natural plague foci in Junggar Basin.

METHODSSample materials and data of animals and vector insects were collected using ecological methods and the population structures were analyzed statistically. F1 antibody of Yersinia pestis in rodents' serum and organ suspension was detected by means of IHA while the pathogen of Y. pestis in rodents and vector insects was detected by means of aetiological detections and the isolated Y. pestis was detected using biochemical methods.

RESULTSThe small mammals which were found in Junggar Basin belonged to 17 species of 11 genera 7 families. Of them, 13 species of rodents were included whose parasitic fleas belonged to 19 species of 10 genera 8 families. The average coverage of Rhombomys opimus hole-community was 22.5% in Junggar Basin with the average density of R. opimus hole-community was 15.9/hm2 and the average rate of habitat of the hole-community was 70.2%. In the R. opimus community, the average density of rodents was 3.1/hole-community, and 34.4/hm2 in the nature plague foci. In the population structure of the hole-community of R. opimus, R. opimus accounted for 72.9% in the total captured rodents, Meriones meridianus was 24.5% while the others were 2.6%. In the nocturnal community of rodents, M. meridianus accounted for 64.0% in total captured rodents, Dipus sagitta was 15.1%, M. erythrourns was 7.5% and the others were 13.4%. In the rodents community of Junggar Basin, the rate of R. opimus with fleas was 84.9%, which was the highest, followed by M. tamariscinus, Euchoreutes naso and M. erythrourns, with the rates as 71.4%, 66.7% and 62.7% respectively. The rate of M. meridianus with fleas was 38.3%. There were 16 species of parasitic fleas in R. opimus, with the total flea index as 8.58 and the dominant species was Xenopsylla skrjabini. There were 17 and 16 kinds of fleas in M. erythrourns and M. meridianus respectively with the total flea index were 1.59 and 1.15, with dominant fleas were Nosopsyllus laeviceps and X. skrjabini. The serum and organ suspension of 3179 rodents which belonged to 12 species were detected by means of IHA, of them 174 samples were positive and the positive rate was 5.5%. There were 1356 samples of R. opimus in these materials, and 164 were positive, accounted for 12.1%. The samples of M. meridianus were 1255, with 9 positive, accounted for 0.7%. The samples of D. sagitta were 116 with 1 positive and the rate was 0.9%. The samples of other rodents were 452 but were all negative. There were in total 2975 organs collected from rodents, when detected by methods of isolated of Y. pestis. 15 strains of Y. pestis were isolated from 1243 R. opimus, and 2 strains isolated from 1230 M. meridianus. A total number of 11 647 fleas from rodents were detected by methods of isolated of Y. pestis in which 1 strain of Y. pestis was isolated from 4713 X. skrjabini, and 6 were isolated from 2101 Xenopsylla minax, 1 from 328 Xenopsylla conformis conformis and 1 from 250 Echidnophaga oschanini. Among the other 4255 fleas, none was isolated. The biochemical properties of these Y. pestis which isolated from Junggar Basin were positive of Maltose, Ejiao sugar and Glycerol, and negative of Rhamnose and Nitrogen, which were all strongly poisonous to mouse.

CONCLUSIONThe natural plague foci in Junggar Basin spread all over the whole Junggar Basin. There were animal plague cases found in 12 counties (cites) while Karamy, Bole, Jimusaer and Qitai were confirmed as plague foci counties (cities). Animals and vector insects of the foci were complicated but the ecological system was stable. R. opimus was recognized as the dominant host animal and its biochemical type belonged to the Middle Ages, suggesting that the foci was a new type of natural plague foci.

Animals ; China ; epidemiology ; Gerbillinae ; microbiology ; Mice ; Plague ; epidemiology ; microbiology ; Rodent Diseases ; epidemiology ; microbiology ; Yersinia pestis ; immunology ; pathogenicity

Pneumonic plague that originated in Russian Siberia broke out in Northeast China in October 1910-March 1911. On the basis of field visits, autopsy, bacteriological identification, and close collaboration with local authorities and international colleagues, Dr. Wu Lien-Teh implemented a series of efficient antiplague measures, which successfully controlled the development of an extraordinary epidemic plague. In his subsequent work, Dr. Wu demonstrated the respiratory transmission of pneumonic plague and tarbagans' role in this spread. Dr.Wu's academic and cultural contributions are valuable in the medical progress in China.
China ; Epidemiology ; history ; History, 20th Century ; Humans ; Plague ; history ; mortality ; prevention & control ; transmission

The risk of plague epidemics and relapse of various types of plague foci persists in Inner Mongolia Autonomous Region. For Marmota sibirica plague foci, the animal plague has not been found but antibody has been detected positive. Nowadays, Marmota sibirica has been increasing in population and distribution in China. In bordering countries Mongolia and Russia, the animal plague has been continuously prevalent. For Spermophilus dauricus plague foci, the animal plague has been taken place now and then. Compared to the above foci, the animal plague is most prevalent in Meriones unguiculatus plague foci and frequently spread to humans. Due to higher strain virulence and historical disaster in Marmota sibirica plague foci and Spermophilus dauricus plague foci, plague prevention and control should be strengthened on these foci. In addition to routine surveillance, epidemic dynamics need to be further monitored in these two foci, in order to prevent their relapse and spread to humans.
Animals ; China/epidemiology* ; Epidemics ; Humans ; Plague/prevention & control* ; Prevalence ; Sciuridae ; Yersinia pestis

Animals ; China ; epidemiology ; Genotype ; Geography ; Humans ; Marmota ; microbiology ; Plague ; epidemiology ; microbiology ; Yersinia pestis ; classification ; genetics ; isolation & purification

Adolescent ; Adult ; Age Distribution ; Aged ; Aged, 80 and over ; Child ; Child, Preschool ; China ; epidemiology ; Humans ; Middle Aged ; Plague ; epidemiology ; Yersinia pestis