Tiegang Li

Publications (6)17.19 Total impact

• Source

  Available from: besjournal.com

  Article: Epidemiological survey and analysis on an outbreak of gastroenteritis due to water contamination.

  ZhiCong Yang, XinWei Wu, TieGang Li, MeiXia Li, Yi Zhong, YuFei Liu, Zhiai Deng, Biao DI, Cong Huang, HuiYing Liang, Ming Wang
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  ABSTRACT: To document the investigation and control of an outbreak of gastroenteritis in City G, South China, and provide a reference for preventing future outbreaks. An ambispective cohort study was designed. Attack rate (AR) and relative risks (RR) were calculated to identify the causes of gastroenteritis. Investigations using questionnaires included personal interviews with patients and doctors, reviews of medical records, laboratory examinations of fecal specimens and continuous hygiene monitoring of water samples from the waterworks. Overall, 427/71534 (AR=5.97%) cases were identified between October 31 and November 12 2010. Geographic distribution was highly localized, with 80% of cases occurring in the areas supplied by waterworks-A. Consumption of water provided solely by waterworks-A was found to be associated with illness (RR=8.20, 95 CI%:6.12-10.99) compared with that from waterworks-B. Microbiological analyses confirmed the presence of Norovirus in six of eight fecal samples from symptomatic patients, two water samples from waterworks-A and two sewage samples. After taking effective measures, the hygienic indices of waterworks-A met health criteria again on November 9 and no cases were reported 3 days later. The outbreak reported here was caused by drinking tap water contaminated with sewage at the source. Early identification of possible contamination sources and awareness of changes that might negatively impact water quality are important preventive measures to protect public health.
  Biomedical and Environmental Sciences 06/2011; 24(3):275-83. · 1.35 Impact Factor
• Article: Epidemiological investigation of an outbreak of pandemic influenza A (H1N1) 2009 in a boarding school: serological analysis of 1570 cases.

  Tiegang Li, Yang Liu, Biao Di, Ming Wang, Jichuan Shen, Ying Zhang, Xi Chen, Jun Yuan, Jibin Wu, Kuibiao Li, Enjie Lu, Yejian Wu, Aihua Hao, Xiongfei Chen, Yulin Wang, Jianhua Liu, Sam Pickerill, Bojian Zheng
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  ABSTRACT: A large number of 2009 pandemic influenza A (H1N1) infections were localized in school populations. To describe the epidemiology, clinical features and risk factors associated with an outbreak that occurred at a vocational boarding school in Guangzhou, P.R. China. Data were collected prospectively and retrospectively through the use of on-site doctors and a post-outbreak survey and blood collection. The survey was used to confirm symptoms, and to investigate a series of flu-related factors such as dormitory conditions, health habits, vaccine history and population contact history. Blood samples were taken for serological analysis. Pandemic H1N1 infection was initially confirmed by a real-time RT-PCR assay. Following the identification of the outbreak by the Guangzhou CDC on September 4, cases were diagnosed symptomatically and retrospectively by serological analysis using the hemagglutination inhibition assay and a neutralization assay. The infection rate was 32% (505/1570) and the attack rate was 22.2% (349/1570). The asymptomatic infection rate was 9.9% (156/1570). Sharing a classroom (OR=2.17, 95% CI: 1.62-2.91) and dormitory space (OR=2.32, 95% CI: 1.84-2.93) was associated with higher rates of infection. Opening windows for ventilation was the only control measure that significantly protected against infection. Social isolation and quarantine should be used to prevent the spread of infection. Ventilation and a control of air flow between classrooms and dorms should be implemented as possible. School closures may be effective if implemented early.
  Journal of clinical virology: the official publication of the Pan American Society for Clinical Virology 03/2011; 50(3):235-9. · 3.12 Impact Factor
• Source

  Available from: Chuanxi Fu

  Article: A two-year surveillance of 2009 pandemic influenza A (H1N1) in Guangzhou, China: from pandemic to seasonal influenza?

  Tiegang Li, Chuanxi Fu, Biao Di, Jibin Wu, Zhicong Yang, Yulin Wang, Meixia Li, Jianyun Lu, Yiyun Chen, Enjie Lu, Jinmei Geng, Wensui Hu, Zhiqiang Dong, Meng-Feng Li, Bo-Jian Zheng, Kai-Yuan Cao, Ming Wang
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  ABSTRACT: In this two-years surveillance of 2009 pandemic influenza A (H1N1) (pH1N1) in Guangzhou, China, we reported here that the scale and duration of pH1N1 outbreaks, severe disease and fatality rates of pH1N1 patients were significantly lower or shorter in the second epidemic year (May 2010-April 2011) than those in the first epidemic year (May 2009-April 2010) (P<0.05), but similar to those of seasonal influenza (P>0.05). Similar to seasonal influenza, pre-existing chronic pulmonary diseases was a risk factor associated with fatal cases of pH1N1 influenza. Different from seasonal influenza, which occurred in spring/summer seasons annually, pH1N1 influenza mainly occurred in autumn/winter seasons in the first epidemic year, but prolonged to winter/spring season in the second epidemic year. The information suggests a tendency that the epidemics of pH1N1 influenza may probably further shift to spring/summer seasons and become a predominant subtype of seasonal influenza in coming years in Guangzhou, China.
  PLoS ONE 01/2011; 6(11):e28027. · 4.09 Impact Factor
• Source

  Available from: PubMed Central

  Article: Antibody dynamics of 2009 influenza A (H1N1) virus in infected patients and vaccinated people in China.

  Ming Wang, Jun Yuan, Tiegang Li, Yang Liu, Jibin Wu, Biao Di, Xi Chen, Xinhong Xu, Enjie Lu, Kuibiao Li, Yanhui Liu, Yejian Wu, Xiongfei Chen, Peng He, Yulin Wang, Jianhua Liu
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  ABSTRACT: To evaluate the risk of the recurrence and the efficiency of the vaccination, we followed-up antibody responses in patients with the 2009 pandemic H1N1 influenza and persons who received the pandemic H1N1 vaccine in Guangzhou China. We collected serum samples from 129 patients and 86 vaccinated persons at day 0, 15, 30, 180 after the disease onset or the vaccination, respectively. Antibody titers in these serum samples were determined by haemagglutination inhibition (HI) assay using a local isolated virus strain A/Guangdong Liwan/SWL1538/2009(H1N1). HI antibody positive rate of the patients increased significantly from 0% to 60% at day 15 (χ(2) = 78, P<0.001) and 100% at day 30 (χ(2) = 23, P<0.001), but decreased significantly to 52% at day 180 (χ(2) = 38, P<0.001), while that of vaccinated subjects increased from 0% to 78% at day 15 (χ(2) = 110, P<0.001) and 81% at day 30 (χ(2) = 0.32, P = 0.57), but decreased significantly to 34% at day 180 (χ(2) = 39, P<0.001). Geometric mean titers (GMT) of HI antibodies in positive samples from the patients did not change significantly between day 15 and day 30 (T = 0.92, P = 0.36), but it decreased significantly from 80 at day 30 to 52 at day 180 (T = 4.5, P<0.001). GMT of vaccinated persons increased significantly from 100 at day 15 to 193 at day 30 (T = 4.5, P<0.001), but deceased significantly to 74 at day 180 (T = 5.1, P<0.001). Compared to the patients, the vaccinated subjects showed lower seroconversion rate (χ(2) = 11, P<0.001; χ(2) = 5.9, P = 0.015), but higher GMT (T = 6.0, P<0.001; T = 3.6, P = 0.001) at day 30 and day 180, respectively. Vaccination of 2009 influenza A (H1N1) was effective. However, about half or more recovered patients and vaccinated persons might have lost sufficient immunity against the recurrence of the viral infection after half a year. Vaccination or re-vaccination may be necessary for prevention of the recurrence.
  PLoS ONE 01/2011; 6(2):e16809. · 4.09 Impact Factor
• Article: Immunogenicity associated with the routine use of an influenza A H1N1 vaccine in health care personnel in Guangzhou, China.

  Biao Di, Xinhong Xu, Tiegang Li, Enjie Lu, Jibin Wu, Yanhui Liu, Yiyun Chen, Sam Pickerill, Ming Wang
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  ABSTRACT: We present immunogenicity data on the routine vaccination of 103 health care personnel during the 2009 H1N1 national vaccination campaign. The seroprotection rate (percentage of samples with hemagglutination inhibition titers of > or =1:40) was 83.2% at 30 days postvaccination, lower than those obtained in previously published controlled trials. Low baseline antibody levels and an increase in seroprotection in a negative-control cohort suggest that the virus remains prevalent.
  Clinical and vaccine immunology: CVI 09/2010; 17(9):1478-80. · 2.37 Impact Factor
• Article: Mycobacterium abscessus post-injection abscesses from extrinsic contamination of multiple-dose bottles of normal saline in a rural clinic.

  Jun Yuan, Yufei Liu, Zhicong Yang, Yanshan Cai, Zhiai Deng, Pengzhe Qin, Tiegang Li, Zhiqiang Dong, Ziqiang Yan, Duanhua Zhou, Huiming Luo, Huilai Ma, Xinglin Pang, Robert E Fontaine
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  ABSTRACT: We investigated an outbreak of gluteal abscesses following intramuscular (IM) injections given at a clinic in rural China to identify the causative agent, source, and method of exposure. We defined a case as an abscess that appeared at the site of an injection given since June 1, 2006. We compared case rates by injection route, medication, and diluents. We reviewed injection practices, and cultured abscesses and environmental sites for mycobacteria. From October through December 2006, 5.8% (n=35) of 604 persons who had received injections at the clinic developed a case. All 35 cases occurred in 184 patients (attack rate=19.0%) who had received IM injections with various drugs that had been mixed with normal saline (NS); risk ratio=infinity; p<0.0001. No cases occurred in the absence of NS exposure. We identified Mycobacterium abscessus from eight abscesses and from the clinic water supply, and observed the inappropriate reuse of a 16-gauge needle left in the rubber septum of 100 ml multiple-dose bottles of NS in the clinic. Fourteen percent (n=527) of the 3887 registered residents of this village had been treated with IM drugs over a three-month period, often for minor illnesses. This outbreak of M. abscessus occurred from exposure to extrinsically contaminated NS through improper injection practices. Frequent treatment of minor illnesses with IM injections of antibiotics was likely an important contributing factor to the size of this outbreak.
  International journal of infectious diseases: IJID: official publication of the International Society for Infectious Diseases 03/2009; 13(5):537-42. · 2.17 Impact Factor