Publications (6)0 Total impact
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Article: [A norovirus-borne outbreak caused by contaminated bottled spring water in a school, Zhejiang province].
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ABSTRACT: To study a local hospital reported acute gastroenteritis in a boarding school on its source of infection, mode of transmission and risk factors of the infection. A suspected case was defined as who had developed diarrhea (≥ 3 times/day) or vomiting among teachers or students of the school, during April 19 - 30, 2010. A confirmed case was from a probable case plus tested positive for norovirus in stool specimens by using RT-PCR. Stool specimens of cases and environmental specimens were collected for laboratory diagnosis. In a case-control study, we compared exposures to sources of bottled water, consumption of bottled water, and hygienic habits of 220 probable or confirmed cases from April 21 - 23 in the peak of the outbreak, together with another 220 controls, with frequency-matched by school grade. 20.3% of the 1536 students but none of the teachers developed the disease. 98.6% of the cases (n = 217) and 85.5% (n = 188) of the controls had drunk bottled water in the classroom (OR(M-H) = 12.3, 95%CI: 3.7 - 40.9). 47.9% (n = 104) of the cases and 41.5% (n = 78) of the controls had drunk unboiled bottled water in classroom (OR(M-H) = 3.8, 95%CI: 1.5 - 9.6). 47.9% (n = 104) of the cases and 48.4% (n = 91) of the controls had drunk bottled mixed water (boiled and unboiled) in the classroom (OR(M-H) = 2.8, 95%CI: 1.1 - 7.0). Stool specimens from 3 cases and one bottle of uncovered bottled water in classroom showed positive of having norovirus genotype II. Coliforms was cultured much higher rates than standard deviations in the bottled water. The factory making the bottled water was not licensed or having strict disinfection facilities. Bottled spring water contaminated by norovirus was responsible for this outbreak.Zhonghua liu xing bing xue za zhi = Zhonghua liuxingbingxue zazhi 08/2011; 32(8):800-3. -
Article: [An outbreak of measles among unvaccinated migrant population in Zhejiang province, from June to August, 2010].
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ABSTRACT: On July 6, 2010, the parents of a patient with confirmed measles reported several suspected measles patients with fever and rash in their village. An investigation was carried out to verify and understand the cause of the outbreak. Several suspected cases had an onset of fever and rash in this and other neighboring villages during June 1 to August 3, 2010. A confirmed case was a suspected case with measles-specific IgM identified in the serum. We conducted door-to-door visits and searched the Chinese Center for Disease Control and Prevention Information System to identify cases, also conducted a retrospective cohort study among migrant children aged 8 months-14 years to identify risk factors related to measles. We identified 19 measles cases (17 confirmed case, 2 suspected cases) in the village, and all of them were migrants. Children aged 1-2 years had the highest attack rate (13%). The primary case-patient had onset on the day she arrived in this village (June 4, 2010). Caretakers from an unlicensed private clinic were providing service in the village but did not report the outbreak to the public health authority. The outbreak was identified only after receiving a report from the parents of one of the patients, by that time the outbreak had lasted for one month. The measles vaccine coverage rate was 81% among the 315 migrant children aged 8 months-14 years. Among the 61 unvaccinated children, those who reportedly being contacted a measles patient had a higher attack rate (14/16, 88%) than those who did not (2/45, 4.4%) (Relative risk = 20, Fisher's exact 95% confidence interval: 5.7-94). The low measles vaccine coverage among migrant children and lack of measures taken on the incident, timely isolation diagnosis/reporting by the caretakers from the unlicensed private clinic etc. had contributed to this prolonged outbreak. Measures need to be taken to improve the immunization services for migrant populations and to enhance measles surveillance programs in the area.Zhonghua liu xing bing xue za zhi = Zhonghua liuxingbingxue zazhi 10/2010; 31(10):1163-5. -
Article: [Investigation on a seasonal influenza accompanying with the first locale novel A/H1N1 influenza outbreak in China].
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ABSTRACT: To timely summarize past experience and to provide more pertinent reference for control and prevention in A/H1N1 cases in influenza season. During May 25 to 31, 2009, 2 secondary community cases caused by a influenza A/H1N1 imported case. In the close contacts of 3 A/H1N1 cases, 14 had some aspirator symptoms onset, such as fever (> or = 37.5 degrees C), cough, sore throat and etc. Laboratory tests excluded the infection of A/H1N1 influenza. For throat swab test for the 14 cases, 7 were tested for seasonal influenza virus. A face-to-face or telephone interview was conducted by CDC staff to collect information of 62 close contacts. Of 14 fever cases, there was no significant by differences by age[15-age group: 19.2% (5/26), over 25-age group: 25.0% (9/36); chi(2) = 0.287, P = 0.592]; by sex group [24.0% (6/25) for male and 21.6% (8/37) for female; chi(2) = 0.048, P = 0.826], by working units [dressing and design, photograph, saleroom and others, consumer group: 42.1% (8/19), 27.3% (3/11), 12.5% (2/16) and 6.3% (1/16); chi(2) = 7.653, P = 0.054], by dormitory style [dormitory style = 33.3% (4/12), non-dormitory style = 29.4% (10/34); chi(2) = 0.699, P = 0.403]. All the cases had fever (37.5 - 37.9 degrees C), no case had diarrhea. One in 3 A/H1N1 cases had diarrhea. All the 14 cases were negative result for A/H1N1 RNA. Six from 7 cases were positive for seasonal influenza test. This was a seasonal influenza outbreak happened in the close contacts of first confirmed A/H1N1 cases in community in mainland China. It showed that we should exclude the seasonal influenza in the investigation of A/H1N1 cases in the seasonal influenza period in some time. It is necessary to take effective measure to strengthen the control and prevention of seasonal influenza.Zhonghua yu fang yi xue za zhi [Chinese journal of preventive medicine] 10/2009; 43(10):852-5. -
Article: [Epidemiological characteristic of first case of locally identified A/H1N1 secondary cases caused by imported source of infection in China].
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ABSTRACT: To study the first locally identifed A/H1N1 secondary cases outbreak in China. Interview and field investigation were integrated to describe the whole process of transmission on each case and to illustrate the relationships between the onset of the disease and the retated factors. Two contact persons appearanced fever and whose throat swabs were tested positive to H1N1 viral nucleic acid. The two had a history of contact in a short distance with the initial imported case without any protective measure in the poor air ventilation. The patients clinical situation was slight. The incubation was between 37 hours and 57 hours. No other new case was found after intervention as isolation and antisepsis were taken. This event was proved to be an outbreak of local A/H1N1 secondary cases caused by the imported case. The main mode of transmission was personal contact in a short distance without protection, through air and droplet. The locus with poor air ventilation was high risk place. Contact persons should be observed seven days and tested continuously. Infectivity and pathogenicity of the A/H1N1 virus were limited and appeared weakened by generations. Patient's condition was related with persistence and frequency of contact with the infection sources. Enhancing management of contact persons, health education, early diagnose, early treatment and early insulation were effective measures of controling and prenventing the spread A/H1N1.Zhonghua liu xing bing xue za zhi = Zhonghua liuxingbingxue zazhi 07/2009; 30(7):684-6. -
Article: [Application of pulse-field gel electrophoresis analysis in the source-tracking of cholera epidemics].
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ABSTRACT: To apply pulse-field gel electrophoresis analysis(PFGE) in the analysis of cholera outbreak events and to determine the molecular epidemiological characteristics of Vibrio cholerae ( V. cholerae) isolates. PFGE using restriction enzyme Not I was employed in the molecular subtyping of forty-one strains of V. cholerae isolated in cholera outbreak events from 2003 to 2005 in Guangzhou area and PFGE patterns were analyzed by BioNumerics Version 4.0 software to perform cluster analysis. Pattern profiles were compared by utilizing of Dice coefficient and UPGMA(unweighted pair group method with arithmetic averages). Comparison of PFGE typing results was performed with phage-biological typing and pathogenicity-associated genes typing. In cholera outbreak events, PFGE could discriminate epidemiologically related and unrelated strains, having more discriminatory power than phage-biological typing and pathogenicity-associated genes-typing. Molecular sub-typing by PFGE could disclose the epidemiological relationships of strains from humans and the environment, providing molecular epidemiological evidence and support for the source-tracking of cholera outbreak events.Zhonghua liu xing bing xue za zhi = Zhonghua liuxingbingxue zazhi 02/2007; 28(1):61-4. -
Article: [Analysis of characteristics of major pathogenicity-related genes of Vibrio cholerae isolated in Guangzhou area from 2001 to 2005].
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ABSTRACT: To apply multiplex polymerase chain reaction (MPCR) assay and sequencing in study of the carrying status of four pathogenicity-related genes of Vibrio cholerae (V.cholerae) and the variation of ctxA. Primers targeting cholera toxin sub-unit A gene (ctxA), toxin-coregulated pilus gene (tcpA), accessory cholera enterotoxin gene (ace), zonula occludens toxin gene (zot) were designed and the MPCR method was applied to detect the pathogenicity-related genes of 276 strains of V.cholerae isolates. The amplified fragments of ctxA gene were sequenced and the genetic homology of the amplified fragments of ctxA was analyzed. Of the 276 strains of V.cholerae, 93.9% strains from human sources belong to the pathogenicity-related genes type A (ctxA(+)tcpA(+)ace(+)zot(+) type) and 6.1% belong to pathogenicity-related genes type C (ctxA(-)tcpA(-)ace(-)zot(-) type). Type A strains from clinical sources were isolated from patients with mild to severe symptom and carriers, among which 68.5% were isolated from patients with mild symptom and 21.9% from carriers. All 63.6% of type C strains from clinical sources were isolated from patients with mild symptom and 36.4% from carriers. The proportion of type C strains that caused mild symptom was higher than that of type A strains. Of the 78 strains isolated from the environment, 9.0% strains belong to pathogenicity-related type A and 35.9% belong to the pathogenicity-related genes type B (ctxA(-)tcpA(-)ace(+)zot(+) type), while 55.1% belong to pathogenicity-related genes type C. The sequencing results showed little genetic variation among the amplified fragments for ctxA. MPCR disclosed the polymorphic status of pathogenicity-related gene patterns in V.cholerae isolates of Guangzhou, providing effective means for further study on evolution of pathogenicity-related genes among V.cholerae isolates from human and environmental sources. This study also offers significant guidance for effective prevention, control and warning against cholera epidemic in local area.Zhonghua yu fang yi xue za zhi [Chinese journal of preventive medicine] 08/2006; 40(4):257-61.
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2011
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Chinese Center For Disease Control And Prevention
Beijing, Beijing Shi, China
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