OBJECTIVETo understand pathogen patterns of enteric infectious diseases and its impact on this pattern due to aggregation of a great deal of foreign visitors during Beijing Olympic Games.

METHODSThe diarrheal patient's rectal swabs and stool specimens were collected from Olympic stadium and hospitals of four districts, including Dongcheng, Xicheng, Haidian and Chaoyang. Enteric multiple pathogens were detected from the total 45 specimens. The culture method was used for the enteric bacteria, ELISA and RT-PCR for the enteric viruses. Molecular typing of Salmonella Enteritidis isolation was completed by PFGE.

RESULTSIt was found that 26 out of 45 cases were positive with 57.8 percent for pathogen detection, and 24 were identified as enteric pathogenic bacteria, including Vibrio parahaemolyticus, Salmonella, diarrheagenic Escherichia coli and Campylobacter jejuni, two as norovirus. There were mixed infections of two pathogenic bacteria for three cases. Ten kinds of pathogens were detected from foreign cases, while five kinds from Chinese cases. A total of 5 PFGE patterns were identified in 10 Salmonella Enteritidis isolates from national and foreign diarrheal cases, which were concentrative in some extent.

CONCLUSIONVibrio parahaemolyticus, Salmonella, diarrheagenic Escherichia coli and Campylobacter jejuni were found to be the primary bacterial pathogens during the Olympic Games. Enteric virus infection existed in summer diarrhea.

Adult ; Bacterial Typing Techniques ; Campylobacter jejuni ; classification ; isolation & purification ; China ; Diarrhea ; epidemiology ; etiology ; microbiology ; virology ; Enterobacteriaceae ; classification ; isolation & purification ; Enterovirus ; isolation & purification ; Escherichia coli Infections ; microbiology ; Female ; Humans ; Male ; Salmonella ; classification ; isolation & purification ; Shigella ; classification ; isolation & purification ; Sports ; Vibrio parahaemolyticus ; classification ; isolation & purification

In 2007, an outbreak of acute hemorrhagic conjunctivitis (AHC) occurred in Beijing. In order to identify the etiology of this outbreak, 57 eye conjunctival swabs were collected from 57 outpatient patients, and detected for adenovirus, human enterovirus 70 (HEV70) and Coxsackievirus A24 variant (CVA24v) genes by using RT-PCR or PCR methods. The results showed that 38 were positive for CVA24v, the positive rate was 66.7%, but none was positive for HEV70 and adenovirus, showing that this outbreak was caused by CVA24v. 9 viral isolates were obtained from 57 clinical specimens by using viral isolation method, and all were identified as CVA24v by molecular typing method. All 9 CVA24v isolates were performed by VP1 sequencing, the results showed that except for strain 0744/BJ/CHN/2007, the variability at nucleotide acid level and amino acid level among other 8 CVA24v were relatively low, and the homologies were more than 99.6% and 100.0%, respectively; the homologies of nucleotide acid and amino acid between strain 0744/BJ/CHN/2007 and other 8 CVA24v were 96.8%-97.2% and 99.7%, respectively. Phylogenetic analysis of 9 CVA24v revealed that they represented the Clade 4 and Clade 5 in Group I, showed that this outbreak was caused by at least 2 viral transmission chains. Comparing to 3C region of CVA24v frequently used before, VP1 region was considered as the most rigorous target for molecular epidemiology study of CVA24v. To enhance the research of sero-epidemiology and molecular epidemiology of CVA24v and to know the genetic characterizations and molecular evolution of CVA24v are most important to prevent and control the outbreaks of AHC in China.
China ; epidemiology ; Conjunctivitis, Acute Hemorrhagic ; epidemiology ; virology ; Disease Outbreaks ; Enterovirus C, Human ; classification ; genetics ; isolation & purification ; Humans ; Molecular Epidemiology ; Molecular Sequence Data ; Phylogeny ; Viral Proteins ; genetics

OBJECTIVETo investigate the epidemiological characteristics of norovirus infection in Beijing.

METHODSBoth outbreaks and sporadic cases of acute gastroenteritis were studied through questionnaires while the stools of patients were collected. Noroviruses were detected by ELISA or RT-PCR, and PCR products were cloned and sequenced.

RESULTSEight outbreaks were reported between November 2006 and March 2007, which were confirmed as nosocomial infections. A total of 158 positive cases were detected among 409 sporadic cases of acute virus gastroenteritis with a positive rate of 38.63%. The highest positive rate (55.00%) was found in group aged from 40 to 44, while the lowest positive rate (21.74%) fell into groups aged from 55 to 59. The positive cases aged from 6 months to 91 years with the mean age of 40 years old including 84 males and 74 females. Data from sequence analysis showed that norovirus epidemic strains helonged to the GII/4 variants in Beijing, which were almost identical to the variants causing epidemics both in the Netherlands and in Japan.

CONCLUSIONNorovirus was important, causing virus-borne diarrhea between 2006 and 2007 in Beijing, and the epidemic strains were consistent with those isolated from both the Netherlands and Japan in 2006.

Adolescent ; Adult ; Caliciviridae Infections ; epidemiology ; virology ; Child ; Child, Preschool ; China ; epidemiology ; Enzyme-Linked Immunosorbent Assay ; Female ; Humans ; Infant ; Infant, Newborn ; Male ; Middle Aged ; Norovirus ; pathogenicity ; Reverse Transcriptase Polymerase Chain Reaction ; Young Adult

Objective To estimate the real number of novel influenza A(H1N1 ) infection in Beijing, 2009. Methods A multiplier model (Impact 2009 v 1.0 software) based on Monte Carlo approach was used to estimate the real number of novel influenza A (H1N1 ) based on the number of influenza-like illness (ILI) cases, novel influenza A(H1N1 ) positive rate among ILI cases and rate on clinical visit of ILIs in secondary and tertiary hospitals. Results There were 1.80 million (90%CI: 1.46-2.30) estimated novel influenza A (H1N1) cases in 2009 in Beijing with the rate of infection as 11.0%. One reported case would represent 167 real infections. The highest age groups of infection were 0-4 years and 5-14 years, being 32.5% and 33.3%, respectively. Conclusion Laboratory-confirmed infections with novel influenza A (H1N1 ) only represented a fraction of the total cases in a population, suggesting that it was imperative to estimate the real number of novel influenza A (H1N1) infection.

Objective: To describe the clinical features, causal agent and transmission mode of a fever outbreak in a school in Shanghai. Methods: Field epidemiological approaches including case definition development, searching for contacts, distribution of diseases description, environmental sampling and laboratory testing. Results: A total of 16 influenza like cases were included, all concentrated in the one class of grade two, including 15 students and 1 teacher. Among student cases, the incidence rate was 36.59% (15/41), the average age was 7.4 years, the incidence rate was 36.84%(7/19) for boys, 36.36%(8/22) for girls. The clinical course was 5-15 days, with the median of 9 days, and 18.75%(3/16) of the cases stayed studying while sick. The nasopharyngeal swab specimens in 16 cases all tested positive for influenza B, of which 11 tested positive for mycoplasma pneumoniae and 1 case also tested positive for coronavirus OC43. Body temperature, number of mononuclear cells, and treatment time of patients infected with Influenza B and mycoplasma pneumoniae were higher than those of patients infected with influenza B alone( P <0.05). The outbreak lasted for 12 days, all sick students were treated and discharged from hospital, with no severe cases or death, and the outbreak was effectively controlled. Conclusion This campus cluster outbreak caused by influenza B and mycoplasma pneumoniae. Patients with influenza B with mycoplasma pneumoniae have severe symptoms and a long course of illness, suggesting the importance of early management of the epidemic.

Objective To investigate the source of the first human case of avian influenza A (H5N1) infection in Beijing. Methods Interviewing the relatives of the case and other key persons, collecting and detecting samples of related biological, epidemiological and environmental data of the case were conducted. Later, the infection source was thoroughly investigated. Results The case ever contacted a slaughtered duck 5 days prior to the onset of illness, and the duck was bought from a stall of a wet market in Yanjiao area of Hebei province. Ten environmental samples were collected in this stall and the neighboring stall of the market. Another 6 samples were tested positive for H5N1 virus by PCR method, with 5 virus strains isolated. The whole-genome sequencing indicated that the amino acid homology between the H5N1 virus strains from the environment and the virus isolated from the case reached 99.8%-100%. Conclusion From both epidemiological and virological evidence, it was proved that the first human case of avian influenza A (H5N1) infection in Beijing was infected by a duck that carrying H5N1 virus the case contacted 5 days proceeding the onset of illness.

OBJECTIVETo evaluate four candidate variable number tandem repeat (VNTR) loci for genotyping Mycobacterium tuberculosis complex strains.

METHODSGenomic sequences for two M. tuberculosis strains (CCDC5079 and CCDC5180) were generated, and using published sequence data, four candidate VNTR loci were identified. The VNTRs were used to genotype 225 Chinese clinical M. tuberculosis complex strains. The discriminatory power of the VNTRs was evaluated using BioNumerics 5.0 software.

RESULTSThe Hunter-Gaston Index (HGI) for BJ1, BJ2, BJ3, and BJ4 loci was 0.634, 0.917, 0.697, and 0.910, respectively. Combining all four loci gave an HGI value of 0.995, thus confirming that the genotyping had good discriminatory power. The HGI values for BJ1, BJ2, BJ3, and BJ4, obtained from Beijing family strain genotyping, were 0.447, 0.878, 0.315, and 0.850, respectively. Combining all four loci produced an HGI value of 0.988 for genotyping the Beijing family strains. We observed unique patterns for M. bovis and M. africanum strains from the four loci.

CONCLUSIONWe have shown that the four VNTR loci can be successfully used for genotyping M. tuberculosis complex strains. Notably, these new loci may provide additional information about Chinese M. tuberculosis isolates than that currently afforded by established VNTR loci typing.

Cluster Analysis ; Genotyping Techniques ; Humans ; Minisatellite Repeats ; Mycobacterium bovis ; genetics ; Mycobacterium tuberculosis ; genetics

OBJECTIVETo investigate the efficacy and advantages of laparoscopy-assisted total gastrectomy (LATG) with D2 dissection of lymph nodes versus conventional open D2 total gastrectomy (OTG) in advanced gastric cancer.

METHODSOne hundred and twenty-five patients with advanced gastric cancer in the middle or upper third of the stomach were operated on from July 2005 to March 2007. Of the patients, 59 cases received LATG and 66 OTG with D2 lymph nodes dissection. Clinical data were recorded and compared between the two groups.

RESULTSNo patient in the LATG group converted to conventional operation with laparotomy. No operation mortality and no severe morbidity occurred in LATG group. As compared with OTG group, in LATG group operation time was longer [(330 +/- 71) min vs. (261 +/- 54) min, P =0.005] in LATG group, but with similar number of lymph node retrieval (36 +/- 13 vs. 34 +/- 16, P =0.450), less operation blood loss [(175 +/- 101) ml vs. (359 +/- 210) ml, P =0.003], earlier recovery of bowel activity (P = 0.015), and a shorter duration of fever after operation (P = 0.024).

CONCLUSIONSLATG with D2 lymph node dissection in advanced gastric cancer is safe and technically feasible with better operative access and visual field, less operation blood loss and earlier recovery.

Adult ; Aged ; Feasibility Studies ; Female ; Gastrectomy ; methods ; Humans ; Laparoscopy ; Lymph Node Excision ; Lymphatic Metastasis ; Male ; Middle Aged ; Stomach Neoplasms ; pathology ; surgery ; Treatment Outcome

OBJECTIVETo evaluate the efficacy and safety of endoscopic mucous resection with transparent cap (EMR-Cap) and endoscopic multi-band mucosectomy (MBM) in the treatment of early esophageal cancer and precancerous lesion.

METHODSA retrospective study was performed to review 30 EMR-Cap cases from December 2008 to December 2009 and 32 MBM cases from January 2010 to January 2011 of early esophageal cancer and precancerous lesions. The differences between these two techniques in efficacy, safety, and cost were compared.

RESULTSIn EMR-Cap group, the median resection time was 26(10-56) min and median procedure time was 43(22-81) min, significantly longer than those in MBM group [10(7-18) min and 32(28-45) min, P=0.036 and 0.038, respectively]. There were no significant differences between the two groups in total thickness and depth of resected lesions (P>0.05). In EMR-Cap group, the median cost was significantly higher than that of MBM group [(5466±354) vs. (4014±368) RMB, P=0.008)].

CONCLUSIONSEMR-Cap and MBM are minimally invasive, safe and effective methods in the treatment of early esophageal cancer and precancerous lesions. Compared to the EMR-Cap, MBM is simple with shorter treatment time and lower cost.

Aged ; Endoscopy ; methods ; Esophageal Neoplasms ; surgery ; Female ; Follow-Up Studies ; Humans ; Male ; Middle Aged ; Mucous Membrane ; surgery ; Precancerous Conditions ; surgery ; Retrospective Studies ; Treatment Outcome

OBJECTIVETo study the epidemiological characteristics and molecular phenotypes of Salmonella by pulsed-field gel electrophoresis (PFGE) in Beijing from 2008 to 2009.

METHODSA total of one hundred thirty-seven isolates recovered from the WHO Global Salmonella Surveillance system and entero clinic surveillance system were identified by biochemical tests and serotyping. The related epidemiological informations were also analyzed. The isolates were further typed by PFGE.

RESULTSThe prevalence of Salmonella from 2008 to 2009 showed obvious seasonal character. High incidence occurred from June to September, and 64.1% (84/131) isolates were recovered in this period. Patients of 18 - 40 year-old were 46.1% (58/128) and 80 patients were male and 40 patients were female with the ratio of 1.57:1. These 137 Salmonella isolates belonged to 20 serotypes, including Enteritidis (46.7%, 64/137) and Typhimurium (17.5%, 24/137) as the dominant serotype. In total, 71 PFGE profiles were identified. Four PFGE patterns of S. Enteritidis isolates (JEGX01.CN0001, JEGX01.CN0003, JEGX01.CN0002, JEGX01.CN0019) and S. Typhimurium pattern of JPXX01.CN0001 were dominant patterns.

CONCLUSIONThe prevalence of Salmonella from 2008 to 2009 showed distribution characteristics of sex, age and seasons. The numerous PFGE patterns of Salmonella showed diversity of these isolates and different clones existed in Beijing.

Adolescent ; Adult ; Bacterial Typing Techniques ; China ; epidemiology ; DNA, Bacterial ; isolation & purification ; Electrophoresis, Gel, Pulsed-Field ; Female ; Food Microbiology ; Humans ; Male ; Molecular Typing ; Salmonella ; classification ; genetics ; isolation & purification ; Salmonella Infections ; epidemiology ; microbiology ; Serotyping ; Young Adult