Sero-epidemiological investigation on hepatitis B among permanent residents in Shenzhen area / 中华流行病学杂志

<p><b>OBJECTIVE</b>To understand the infection status and epidemiological features of HBV in permanent residents of Shenzhen city.</p><p><b>METHODS</b>A multi-stage stratified random sampling method was performed for questionnaire survey to permanently-registered residents of 1-59 years old in Luohu and Baoan district of Shenzhen in 2010, and blood samples of the subjects were collected. Hepatitis B virus-related surface antigen (HBsAg) and hepatitis B virus surface antibody (anti-HBs) were detected with ELISA.</p><p><b>RESULTS</b>The total 3771 studied population showed 252 HBsAg positive and 2712 anti-HBs positive residents with the standardization prevalence as 9.73% and 72.83% , respectively. The difference of the prevalence of HBsAg and anti-HBs between males and females were not statistically significant (P > 0.05). The prevalence of HBsAg was reduced with increasing age. The differences of the prevalence of HBsAg between Shenzhen permanent registered and non-permanent registered population were not significant, but the prevalence of anti-HBs in Permanent registered residents (78.32%) was higher than in non-permanent (66.03%, χ(2) = 41.613, P < 0.001). The prevalence of HBsAg was significantly different in various occupational and educational levels. Peasants had the highest prevalence (24.13%) and medical workers had the highest prevalence of anti-HBs (89.10% ). People with junior high school education had the highest prevalence of HBsAg (12.76%) and the lowest of anti-HBs (62.45%). Population with high-level education had the highest prevalence of anti-HBs(81.00% average). The prevalence of HBsAg was over 10% in people who were born in Shenzhen and Guangdong province, and the anti-HBs was the highest in Shenzhen population with the prevalence as 74.48% and 76.47% , respectively.</p><p><b>CONCLUSION</b>In the Shenzhen resident population, the overall prevalence of HBV was lower than the average level of Guangdong province, but higher than the national wide.</p>

Etiologic and molecular characteristics of Vibrio parahaemolyticus strains isolated from diarrheal patients in Shenzhen, in 2007-2008 / 中华流行病学杂志

Objective To study the infection status and the molecular characteristics of Vibrio parahaemolyticus isolated from diarrheal patients in Shenzhen, in 2007 to 2008 and to provide evidence for the prevention and control of diarrheal diseases caused by Vibrio parahaemolyticus. Methods More than 80 fecal specimens from four sentinel surveillance hospitals were collected and cultured each month. A total of 361 isolates of Vibrio parahaemolyticus were sero-typed and examined by real-time PCR for the presence of two major virulence genes, tdh and trh. Of 361 strains, 60 O3: K6 strains isolated from six suspected outbreaks in August, 2007 and in September, 2008 were typed by pulsed-field gel electrophoresis (PFGE). Results 4384 stool samples were detected in four sentinel surveillance hospitals and with 361 Vibrio parahaemolyticus strains isolated that belonged to 28 serotypes. Serotype O3:K6, O4:K8 and O1:KUT accounted for 67.90%, 7.50% and 6.10%, respectively. Of 361 strains, 337 strains belonged to tdh + trh- , 11 strains were tdh-trh- and 13 strains were tdh + trh +. The most prevalent serotype which caused diarrheal diseases was tdh + trh-in Shenzhen. The 60 isolates were discriminated into twenty different PFGE patterns, which belonged to three clones. Among the 60 isolates, most of the PFGE patterns of isolates from the suspected outbreak locations were identical and some strains isolated from different year were different. Conclusion Vibrio parahaemolyticus isolates in Shenzhen were dominated by O3:K6 strains. Most of these isolates carried tdh gene and few carried trh gene. Meanwhile, the identical patterns of isolates from 6 suspected outbreaks locations demonstrated that Vibrio parahaemolyticus outbreaks occurred in July 2007 and in September 2008 in Shenzhen. However, the dominated strains' PFGE patterns were different each year, indicating that the sources of Vibrio parahaemolyticus had a multiplex nature and the multiplex sources such as water, sea food and pickled products should be integrated monitored. Laboratory based surveillance of diarrheal diseases could contribute in establishing early warning system for the better prevention and control of diarrheal diseases.

A case of human highly pathogenic avian influenza in Shenzhen, China: application of field epidemiological study / 中华流行病学杂志

<p><b>OBJECTIVE</b>Based on analyzing the characteristics of a case with human avian influenza and the effects of field epidemiological study.</p><p><b>METHODS</b>An emergency-response-system was started up to follow the probable human Highly Pathogenic Avian Influenza case initially detected by the "Undefined Pneumonia Surveillance System of Shenzhen". Public health professionals administered several epidemiologic investigations and giving all the contacts of the patient with a 7-day-long medical observation for temporally related influenza-like illness. Reverse transcriptase-polymerase chain reaction (RT-PCR) with primers for H5 and N1 was applied to test respiratory tract samples and/or throat swabs of the patient and all his contacts specific for the hemagglutinin gene of influenza A H5N1. Activities and strategies such as media response,notification in the public, communications with multiple related sectors, social participation and information exchange with Hong Kong were involved in field control and management.</p><p><b>RESULTS</b>The patient was a male, 31 years old,with an occupation as a truck driver in a factory,and had been residing in Shenzhen for 7 years. Started with an influenza-like syndrome, the patient received treatment on the 4th day of the onset, from a clinic and on the 6th day from a regular hospital. On the 8th day of the disease course, he was confirmed by Shenzhen Center for Disease Control and Prevention as human avian flu case and was then transferred to Intensive Care Unit (ICU). On the 83rd day of commence, the patients was healed and released from the hospital. The patient had no significant exposure to sick poultry or poultry that died from the illness before the onset of the disease. The patient and five family members lived together, but no family member was affected and no contact showed positive results for H5N1. A small food market with live poultry, which was under formal supervision and before illness the patient once visited, located near his apartment. Totally, 35 swabs from live birds and bird's coops in the market for H5 nucleic acid were tested and all were negative. The influenza H5N1 virus isolated for the case was named as A/Guangdong/02/2006 (H5N1) or GD/2/06. Phylogenetic relationships and molecular characterization analysis revealed that all the segments of the H5N1 virus named GD/2/06 still belonged to avian segments. Investigation process and control measures were released to the general public through the media. Soon after the laboratory confirmation, information was released to the society, as well as Hong Kong Center for Health Protection. Local Departments of Agriculture, Industries & Business, and Entry-Exit Inspection & Quarantine Bureau together with the Public Health Department put up combined actions. A computer-based telephone survey was initiated to investigate attitudes and knowledge of residents in town, revealing that positive atmosphere dominated and no panic existed.</p><p><b>CONCLUSION</b>Rapid laboratory diagnosis of the virus was the key for successful treatment and survival result of the case. Still, the pathogen was from birds resources. No human-to-human transmission was observed, however, source of infection was unclear. Field epidemiological study could offer special methods for the responses of emergency public health problems.</p>