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Jie Li,
Changying Lin,
Mei Qu,
Xinyu Li,
Zhiyong Gao, Xin Zhang,
Yuan Liu,
Ying Huang,
Xiaoli Wang,
Lei Jia,
Xitai Li,
Guirong Liu,
Hanqiu Yan,
Lijuan Chen,
Quanyi Wang
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ABSTRACT: BACKGROUND: Hand, foot and mouth disease (HFMD) is a common illness in young children. It also can be seen in adults occasionally. Enterovirus 71 (EV71), a pathogen that causes not only HFMD but also neurological complications and even death, has caused many HFMD outbreaks in China. However, till now the data about the duration of EV71 shedding is very limited. RESULTS: A total of 136 throat swabs and fecal samples were collected from 27 children and 3 adults, which includs 7 close contacts, 9 mild cases and 14 severe cases,. The participants were divided into three groups namely, severe case group, mild case group and close contact group. All the samples were assayed with real-time polymerase chain reaction (PCR). Kruskal-Wallis Test was employed to compare the difference in duration of viral RNA shedding among three groups. The results showed that significant difference in duration of EV71 shedding was found among three groups (P < 0.01). The longest duration of EV71 shedding in fecal samples is 54 days and 30 days in throat swabs. CONCLUSIONS: HFMD is characterized by extended excretion of EV71. Our results suggest that the duration of EV71 shedding is correlated with the severity of the disease. EV71 shedding through feces can persist more than 54 days. Prolonged virus shedding is a potential risk factor of proliferating HFMD epidemic.
Virology Journal 01/2013; 10(1):31. · 2.34 Impact Factor
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Guilan Lu,
Hanqiu Yan,
Yaowu Yang,
Shujuan Cui,
Yanning Lü, Xin Zhang,
Daitao Zhang,
Peng Yang,
Fang Huang,
Jianwei Wang,
Quanyi Wang
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ABSTRACT: Active surveillance and diagnosis of the influenza pandemic (H1N1) 2009 (pH1N1) have played a critical role in the effective control and prevention of the pandemic in China. Although several commercially available real-time PCR kits for pH1N1 virus have been used in diagnostic laboratories in Beijing, little has been known about the performance of these kits for detecting pH1N1 virus. In this study, the performance of two commercial real-time PCR kits in Beijing was evaluated. Analysis of clinical samples showed that the positive detection rate for the AgPath-ID™ kit (38.2%) was significantly higher than that for the Da An H1N1 kit (30.0%) (McNemar's chi-square test, P=0.000). The limit of detection (LOD) of the AgPath-ID™ kit was 10(2), 10(2), and 10(3) copies/reaction for the Influenza A (set 1), H1N1 Influenza A (set 2) and H1N1 Influenza A Sub H1 (set 3) genes, respectively, whereas the LOD of the Da An kit was 10(3) copies/reaction for both H1 and N1 genes. Although the AgPath-ID™ kit exhibited a significantly higher detection rate for pH1N1 than the Da An kit, cross-reactivity to A/PR8/34 was found for the AgPath-ID™ kit for H1N1 Influenza A (set 2).
Journal of virological methods 12/2012; · 2.13 Impact Factor
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ABSTRACT: To study the etiological detection on samples from severe hand-foot-mouth disease (HFMD) cases and the genetic characteristics of enterovirus type 71 (EV71) isolates from severe patients in Beijing, 2010.
Real-time RT-PCR was used to detect EV71 and Coxsackievirus A16 (CoxA16) and RD cells were used to separate virus strains from samples. Homogeneity of EV71 isolated strains were also analyzed.
Four hundred and fourty-two severe cases were detected and 253 were positive, taking up 57.24% of the total (253/442). The overall positive detection rate on EV71 was 54.55% (138/253), with CoxA16 as 5.93% (15/253), and with other enterovirus group was 39.53% (100/253). The nucleotide homogeneity of VP1 within these 12 strains was 97.2% - 100.0%, and with Beijing strains in 2007 - 2010, Shandong strains in 2007 and Anhui Fuyang strains in 2008 and the Guangdong strains in 2008 as 94.0% - 99.9%.
Severe HFMD cases were most oftenly caused by EV71 but less caused by CoxA16 or other enterovirus. The HFMD in 2010 in Beijing was mainly caused by EV71 subgenotype C4a with 4 transmission chains. Twelve isolated EV71 strains had high homogeneity with strains isolated from severe cases in Anhui Fuyang in 2007.
Zhonghua liu xing bing xue za zhi = Zhonghua liuxingbingxue zazhi 09/2012; 33(9):926-9.
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Mei Qu,
Ying Deng, Xin Zhang,
Guirong Liu,
Ying Huang,
Changying Lin,
Jie Li,
Hanqiu Yan,
Xitai Li,
Lei Jia,
Biao Kan,
Fang Huang,
Quanyi Wang
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ABSTRACT: Acute diarrhea is of great concern due to considerable morbidity and mortality worldwide. The causative bacteria leading to acute diarrhea in general population remains unclear in China. This study was conducted to determine the etiology of acute diarrhea using a sentinel hospital-based surveillance network in Beijing.
Active surveillance was implemented from April 2010 to December 2011 on two random days per week by enrolling every tenth diarrheal patients admitted to seventeen intestinal clinics. Shigella spp., Vibrio spp, Salmonella spp., diarrheagenic Escherichia coli and other genera of bacteria, were investigated from 4803 outpatients with acute diarrhea by microbiological methods.
The pathogenic bacteria recovered out from fecal samples of 968 (20.2%) patients had the following profile: Shigella spp. (5.9%) was the most prevalent pathogen, Vibrio parahaemolyticus (5.2%), Salmonella spp. (3.9%) and enteropathogenic E. coli (EPEC) (0.9%) had from the second to fourth highest prevalence, respectively. Of the 55 co-infections detected, V. parahaemolyticus was the most common pathogen from 28 cases (50.9%), with the main combination of V. parahaemolyticus and Salmonella. The highest proportion of all causative bacteria was found in adults aged 20-39 year and in summer as well as early autumn. The clinical symptoms associated with specific bacterial infection, such as fever, abdominal pain, tenesmus, nausea, vomiting, and watery and bloody stool, were observed frequently in diarrheal patients.
Shigella spp., V. parahaemolyticus, Salmonella spp., and EPEC are important enteropathogenic bacteria causing acute diarrhea in Beijing. To execute reasonable interventions, the comprehensive and continuous surveillance is needed to identify the prevalence of different enteropathogeic bacteria.
The Journal of infection 04/2012; 65(3):214-22. · 4.13 Impact Factor
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ABSTRACT: Selecting variable-number tandem-repeat (VNTR) loci for different serogroups of Shigella spp to explore and establish multilocus variable-number tandem-repeat analysis (MLVA) method, in order to study the molecular characteristic of the isolated strains.
Of the Shigella strains found by dysentery surveillance in Beijing from 2001 to 2009, 180 strains were selected for this study, according to the number and serotypes of the surveillant strains, at the ratio of 15%; including 50 strains of Shigella sonnei and 130 strains of Shigella flexneri. After screening the polymorphism of the 18 VNTR loci, 10 VNTR loci (sh1-sh10) were retained and constructed three groups of multi-PCR methods to detect all he 180 strains and analyze MLVA molecular subtypes using capillary segments.
A range of 2 to 11 alleles were found on the 10 VNTR loci among the 180 Shigella strains, with a diversity index value between 0.158 and 0.766. The 10 loci showed diversity in different serogroups, such as only one allele found in sh6 of Shigella flexneri, sh2 and sh3 of Shigella sonnei individually. The isolated 180 strains were divided into 84 MLVA subtypes, with a resolution ratio D value at 0.967 (95%CI: 0.956 - 0.978). The 130 strains of Shigella flexneri were divided into 63 subtypes, named as TF001-TF063; among which TF001, TF002 and TF 005 were the dominant subtypes, accounting to 17, 16 and 15 strains respectively. The 50 strains of Shigella sonnei were divided into 21 subtypes, named as TS001-TS021; among which TS002 (14 strains) and TS001 (7 strains) were the dominant subtypes.
MLVA subtyping method including 10 VNTR loci was preliminarily developed. The MLVA cluster analysis revealed that the subtypes of Shigella strains isolated in Beijing were diverse, and suggested the possibility of multiple-clone source.
Zhonghua yu fang yi xue za zhi [Chinese journal of preventive medicine] 04/2012; 46(4):329-33.
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Mei Qu, Xin Zhang,
Gui-rong Liu,
Ying Huang,
Jie Li,
Xi-tai Li,
Yuan Liu,
Han-qiu Yan,
Bai-wei Liu,
Xin-yu Li,
Quan-yi Wang,
Fang Huang
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ABSTRACT: To understand the etiological and molecular-epidemiological characteristics of Vibrio parahaemolyticus in Beijing.
Stool specimens from sporadic diarrheal patients were collected during April to December, 2010. Culture and serotyping were used to detect the Vibrio parahaemolyticus from the 2118 specimens. All the positive strains were tested for drug sensitivity by Kirby-Bauer method. Real-time PCR was used to detect the existence of three virulence genes tlh, tdh and trh. Molecular typing on Vibrio parahaemolyticus isolates was completed by pulsed field gel electrophoresis (PFGE).
114 out of the 2118 specimens were Vibrio parahaemolyticus positive, with the positive rate as 5.38%. 114 isolates belonged to 23 serotypes, with the dominant (63.16%) serotype as O3:K6. Strains isolated from clinical manifestation patients were resistant to antibiotics-ampicillin and gentamicin, while with high sensitivity to amoxicillin, ceftriaxone, chloromycetin, imipenem, nalidixic acid and tetracycline. Virulence gene detection was positive to tlh for all the strains, but most to tdh, while only one strain to trh. The positive rate of tdh among O3:K6 strains (98.61%) was higher than that in those non-O3:K6 strains (85.71%) (P = 0.0098). 114 isolates were discriminated into 54 different PFGE patterns, while 72 O3:K6 strains into 34 patterns without the clustering characteristic.
Vibrio parahaemolyticus strains isolated from diarrheal patients in Beijing were dominated by O3:K6 strains, with stronger virulence. The positive rates of genes tlh and tdh were high. Vibrio parahaemolyticus strains showed high sensitivity to most antibiotics. The prevalent Vibrio parahaemolyticus strains in Beijing had various sources of clones.
Zhonghua liu xing bing xue za zhi = Zhonghua liuxingbingxue zazhi 12/2011; 32(12):1255-8.
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Fang Huang,
Ying Deng,
Mei Qu,
Gui-Rong Liu,
Yuan Liu, Xin Zhang,
Jie Li,
Han-Qiu Yan,
Zhi-Yong Gao,
Bai-Wei Liu,
Xi-Tai Li,
Xin-Yu Li
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ABSTRACT: To explore the pathogenic form, epidemic features and serotype distribution of the pathogenic bacteria causing infectious diarrhea in Beijing.
A total of 2118 samples of rectal swabs and stool specimens of diarrheal patients were collected from 6 surveillant intestinal tract clinics during the period between April and October, 2010. Enteric multiple pathogens including Vibrio cholerae, Vibrio parahaemolyticus, Salmonella, Shigella and diarrheagenic Escherichia coli were detected by the isolation culture, biochemical identification and serotyping methods. The population distribution, temporal distribution and serotype distribution of the above pathogenic bacteria were analyzed by descriptive statistical methods.
478 strains isolated from the total 2118 specimens were positive for pathogen detection, accounting to 22.6%. Among the 478 strains of pathogenic bacteria, Shigella accounting for 40.8% (195/478) was the most frequent pathogen, followed by Vibrio parahaemolyticus accouting for 23.8% (114/478), Salmonella accounting for 19.0% (91/478) and diarrheagenic Escherichia coli accounting for 4.8% (23/478). Enteric pathogenic bacteria spread mainly among adults aging between 20 and 39; and the distribution was different among different age groups, while the highest detected rate was in 30 - 39 age group, accounting for 27.2% (92/338). The detected rate of pathogenic bacteria showed evident seasonal variations, with a peak from July to October, whose detected rates were 23.5% (114/486), 32.8% (176/536), 36.1% (90/249) and 25.9% (29/112) respectively. The detected rates in other months were all under 16.0%. Shigella Sonnei was the dominant serotype, accounting for 83.1% (162/195). O3:K6 was the dominant serotype among Vibrio parahaemolyticus, accounting for 63.2% (72/114). Salmonella Enteritidis and Salmonella Typhimurium were dominant serotypes among Salmonella, accounting for 13.2% (12/91) and 12.1% (11/91) separately. Enterpathogenic Escherichia coli and enterotoxigenic Escherichia coli were the dominant serotypes among Diarrheagenic Escherichia coli, accounting for 69.6% (16/23) and 30.4% (7/23) respectively.
The three main pathogenic bacteria causing infectious diarrhea in Beijing are Shigella, Vibrio parahaemolyticus, Salmonella; and there are obvious changes in the serotype distribution of Shigella and Samonella compared to previous years.
Zhonghua yu fang yi xue za zhi [Chinese journal of preventive medicine] 09/2011; 45(9):820-4.
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Mei Qu,
Fang Huang, Xin Zhang,
Dai-tao Zhang,
Gui-rong Liu,
Zhi-Gang Cui,
Han-qiu Yan,
Yuan Liu,
Zhan-ying He,
Xiang-feng Dou,
Biao Kan,
Quan-yi Wang
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ABSTRACT: To study the epidemiological characteristics and molecular phenotypes of Salmonella by pulsed-field gel electrophoresis (PFGE) in Beijing from 2008 to 2009.
A 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.
The 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.
The 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.
Zhonghua yu fang yi xue za zhi [Chinese journal of preventive medicine] 02/2011; 45(2):113-7.
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ABSTRACT: To examine the frequency and distribution of antibodies against pandemic influenza A (H1N1 2009) [H1N1] in populations in Beijing and elucidate influencing factors.
In January 2010, a randomized serologic survey of pandemic influenza A (H1N1 2009) was carried out. Six districts that were randomly selected with a total of 4601 participants involved in the survey have their antibody level tested by hemagglutination inhibition assay.
Among the 4601 participants, the overall seropositive rate for pandemic influenza A (H1N1 2009) antibodies was 31.7%. The seropositivity prevalence in participants who received the pandemic H1N1 vaccination was 60.9%. Only 53.1% of the pandemic influenza A (H1N1 2009) seropositive individuals who had not received the vaccination experienced respiratory tract infection symptoms. Multivariate logistic regression revealed that factors such as age, occupation, dwelling type, whether the participant's family included students in school, and the vaccination history with pandemic influenza A (H1N1 2009) were associated with antibody titers (p<0.05).
Our data indicated that almost 30.0% of the residents had appropriate antibody titers against pandemic influenza A (H1N1 2009) in Beijing, and these titers may provide an immune barrier.
Preventive Medicine 10/2010; 52(1):71-4. · 3.22 Impact Factor
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Peng Yang,
Fang Huang,
Wei-xian Shi,
Gui-lan Lu,
Li-Li Tian,
Shu-juan Cui, Xin Zhang,
Shuang Li,
Bai-wei Liu,
Ying Deng,
Xing-huo Pang,
Quan-yi Wang
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ABSTRACT: To investigate the immunological level against influenza A (H1N1) 2009 in Beijing and provide evidence to evaluate the developing trend of the disease.
Between Nov. 27, 2009 and Dec. 23, 2009, subjects were randomly selected from patients in hospitals (infectious and respiratory diseases related departments were excluded), volunteers in blood donation center and healthy subjects attending the physical examination center. Questionnaire survey was conducted and serum samples were collected to detect the hemagglutination-inhibition (HI) antibody against influenza A (H1N1) 2009 virus.
856 subjects participated in this survey, and 127 showed positive HI antibody to this pandemic virus. The proportions of sero-positivity among 0 - 5, 6 - 17, 18 - 55, ≥ 56 year olds were 14.5%, 19.4%, 17.4% and 8.0% respectively (P = 0.009). There was no significant difference in the sero-positivity between males and females (P = 0.693). The age-adjusted positive rate was 15.8% in the population of Beijing. By multivariate logistic regression analysis, factors as age, acute respiratory symptoms and the rate of pandemic (H1N1) 2009 vaccination were significantly associated with sero-positivity of HI antibody to the influenza A (H1N1) 2009 virus.
Above 15% of the population in Beijing showed protective antibody against influenza A (H1N1) 2009 virus, indicating the development of immunological barrier to this disease had been formed, to some extent.
Zhonghua liu xing bing xue za zhi = Zhonghua liuxingbingxue zazhi 05/2010; 31(5):485-8.
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Fang Huang,
Jing Guo,
Shu-juan Cui,
Yan-ning Lü,
Zhi-yong Gao,
Wei-hong Li,
Han-qiu Yan,
Mei Qu,
Wei-xian Shi,
Gui-lan Lu, Xin Zhang,
Dai-tao Zhang,
Li-li Tian,
Hai-kun Qian,
Peng Yang,
Xing-huo Pang,
Quan-yi Wang
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ABSTRACT: To analyze the results of detection on influenza A (H1N1) 2009 virus in Beijing from May 2009 to December 2009 and to understand the epidemiologic characteristics during the pandemic period.
The study was conducted from the May 1 to December 27, 2009. A total of 101 852 throat swab samples were detected with the real-time RT-PCR assay by the Beijing Network Laboratory. Data was statistically analyzed.
9843 samples showed influenza A (H1N1) 2009 positive, with an overall positive rate as 9.66%. In terms of the positive rates, they were 2.85% from May to June, 3.32% from July to August and 8.35% from September to October. The peak month fell in November (29.67%) and December (24.33%). The positive rates among the following subpopulations were: 8.40% among the suspected cases, 4.75% among close contact cases, 11.46% among the influenza-like illness cases and 7.33% among the cluster cases with fever. Positive cases mainly fell in age groups 5 - 14 and 15 - 24. The ratio of male to female was 1.5:1.
During the pandemic period of influenza A (H1N1) 2009, positive cases gradually increased during May to November but slowly decreasing in December.
Zhonghua liu xing bing xue za zhi = Zhonghua liuxingbingxue zazhi 05/2010; 31(5):494-6.
