河北省固安县某农村HAV,HBV,HCV感染比较流行病学研究

对河北省固安县北斜村ＨＡＶ、ＨＢＶ和ＨＣＶ感染的流行病学特征和传播途径进行了比较研究．该人群ＨＡＶ感染率高达９１％，１０岁以下儿童ＨＡＶ感染率达６８．６％；ＨＢｓＡｇ携带车和ＨＢＶ总感染率分别为３．ｇ％和２５．９％，１０岁以下儿童ＨＢｓＡｇ阳性率和ＨＢＶ感染率分别为２．９％和１７．５％；ＨＣＶ感染率为１２．１％；但２０岁以下和６０岁以上老年人ＨＣＶ感染率仅０．４％。显示ＨＡＶ、ＨＢＶ和ＨＣＶ感染的流行特征明显不同．     

不同人群HCV感染状况及传播途径的研究

应用第二代抗ＨＣＶ ＥＬＩＳＡ试剂对我国中南地区部分人群 ＨＣＶ感染状况进行了血清学调查，同时对ＨＣＶ感染的传播途径进行了研究。结果表明：１．ＨＣＶ感染率在不同人群中检出不一，凡与血液接触频繁的人群感染率较高，如恶性肿瘤患者（９．９％），献血（浆）员（１２．２５％），血液病患者（２４．３％），血液透析者（３７．２％），药瘾者（６０．５％）。无明显血液接触史者则较低，如性错乱者（４．９％），医务人员（０．３３％）及健康孕妇（０．２４％）。２．经血传播是我国ＨＣＶ传播的主要途径。除频繁接触血液者ＨＣＶ感染率高以外，血液制品中丙球制剂抗 ＨＣＶ检出率为 １００％，ＨＣＶ ＲＮＡ阳性率为 ３１． ９％，其余制剂中虽然抗 ＨＣＶ检出率极低，但 ＨＣＶ ＲＮＡ阳性率仍达 ７． ９４％。提示应用被污染的血液制品也存在传播 ＨＣＶ的潜在危险。 ３．性接触和日常生活密切接触有可能传播ＨＣＶ，但机率较低。 ４． ＨＣＶ的家庭内聚集性感染的危险性远低于ＨＢＶ。 ５．职业性暴露感染 ＨＣＶ的危险性亦较低。 上述研究结果为阐明我国 ＨＣＶ感染流行规律及制订ＨＣＶ感染防治措施提供了客观依据。     

甲型肝炎病毒基因分型研究进展

甲型肝炎病毒只有一个血清型，但可划分为７个基因型，其中基因Ⅰ型、Ⅱ型和Ⅶ型主要为人源ＨＡＶ株，基因Ⅱ型为人源或猴源病毒株，基因Ⅳ型Ⅴ型和Ⅵ型则主要为猴源ＨＡＶ株。ＨＡＶ各基因型之间核苷酸差异为１５－２５％，基因亚型间的差异为７．５－１５％。基因分型的研究将为ＨＡＶ的分类提供有用的工具，并为ＨＡＶＣ的流行学追踪调查提供方法。     

115名HBsAg阳性职工HBV感染的血清流行病学调查

１１５名ＨＢｓＡｇ阳性职工ＨＢＶ感染的血清流行病学调查梁云娟人体在感染乙型肝炎病毒（ＨＢＶ）后不同阶段，可出现各种ＨＢＶ．感染标记─—ＨＢｓＡｇ、抗－ＨＢｓ、ＨＢｅＡｇ、抗－ＨＢｅ和－ＨＢｃ，不同个体血清标记会出现不同情况，但只要有其中一种存在，即可...     

一步单管反转录PCR检测水中甲型肝炎病毒

以往甲型肝炎病毒（ＨＡＶ）的检测主要依赖细胞培养法，但此法所需时间长、敏感性低、特异性不强。虽然反转录ＰＣＲ等技术已被用于粪便或食品中ＨＡＶ的检测，但常规反转录ＰＣＲ操作繁琐、污染环节多，极易造成污染，致使实验结果不稳定或出现假阳性结果。为克服ＰＣＲ检测ＨＡＶ的缺点和不足，我们在实验基础上建立了一步单管反转录ＰＣＲ技术检测水中的ＨＡＶ，采用热裂解法提取样品中ＨＡＶ病毒的总ＲＮＡ，反转录与ＰＣＲ反应一步进行，整个反应在一个反应管中进行，操作方法较简单，中间可能污染的环节较少，因此，最大限度的减少了由环境造成的可能污染。我们设计合成的引物（Ｈ１—Ｈ２）在ＨＡＶ病毒核酸的ＶＰ１区，只特异地扩增ＨＡＶ核酸片断，具有较强的特异性。改进后的反转录ＰＣＲ的敏感性与常规反转录ＰＣＲ比有所提高，可检测到细胞培养悬液或水中１０个ＴＣＩＤ＿（５０）的ＨＡＶ。     

哈密地区城乡正常人群病毒性肝炎感染状况分析

应用ＥＬＩＳＡ方法对哈密地区三个民族正常人群病毒性肝炎感染状况进行了血清流行病学调查结果表明：ＨＡＶ及ＨＢＶ感染率以维吾尔族为高，分别为８９．２５和２８．２９％；ＨＢｓＡ携带率以汉族最高；ＨＣＶ及ＨＥＶ感染率也以维吾尔族为高，分别为４．８８５和２．９３％。同时揭示了各型病毒性肝炎在不同年龄，性别上的分布特点。     

1998年吉林省水灾地区甲肝流行状况的调查

甲型肝炎病毒（ＨＡＶ）主要经粪－口传播，在我省流行较广。１９９８年特大洪水过后灾区群众的饮水、饮食等生活条件发生了很大改变。为了解ＨＡＶ在灾区流行状况，我们于９月２０～２５日对白城地区水灾及非水灾区按不同年龄组随机采血３７２人份，对甲肝抗－ＨＡＶＩｇ...     

上海地区散发性病毒性肝炎病原学分型动态分析

本文在上海地区肝炎监测点进行２年２３０００多例的住院急性病毒性肝炎病人的ＨＡＶ、ＨＢＶ、ＨＣＶ和 ＨＥＶ病原学分型，发现甲型肝炎比重在 ４５％～５０％、乙型肝炎 ２８％～３０％、丙型为 ２． ５％、戊型为１５％～２０％，证明甲型肝炎仍是上海地区主要的流行病种，而戊型肝炎的流行已占相当比重。由于５年多来开展大规模乙肝预防接种，乙肝已有一定变化，由于１９９２年上海地区开展了献血员和血库ＨＣＶ筛选工作，丙肝目前的发病还比较平稳，但引起升高的流行因素仍然普遍存在。同时本文还发现了各种肝炎之间的重叠感染现象。     

二氧化氯灭活毛蚶体内HAV的实验研究

二氧化氯灭活毛蚶体内ＨＡＶ的实验研究上海市卫生防疫站２００３３５蒋家，姜培珍，郑春阳，应蓓蓓，诸文浩１９８８年受污染ＨＡＶ的毛蚶曾引起上海３０余万人罹患甲肝，为此，市政府明令禁止毛蚶上市。随着时间的推移，市民对其危害性的认识越来越淡漠，希望毛蚶重返餐...     

厦门市区居民五型病毒性肝炎流行特征

按照全国五型病毒性肝炎血清流行病学调查方案，我市于１９９２年在居民中进行调查，以家庭为单位整群抽样，将１－５９岁居民作为调查对象，共采血样４０３份，共１８０户。各型肝炎总感染率为：ＨＡＶ６８．４９％ＨＶＢ７５．４３％、ＨＣＶ４．２２％、ＨＤＶ５０％、ＨＥＶ２０．６０％，ＨＢｓＡｇ阳性率１１．１７％、抗－ＨＢｃ５７．５７％、抗－ＨＢｓ４１．９４％、ＨＢｅＡｇ１．９９％。调查提示市区居民病毒性肝炎血清     

Analysis of the evolution in the circulation of HAV and HEV in Eastern Spain by testing urban sewage samples

The aim of the study was to analyse the evolution of the prevalence of HAV and HEV in the population of eastern Spain by analysing the viruses excreted in urban sewage. Raw urban sewage samples were collected and analysed during several years using RT-PCR techniques and sequencing analysis. Two limiting regions were analysed, one of them having implemented HAV vaccination programs. Acute symptomatic HEV cases were also examined. Results were compared with those from previous studies in the area using identical methodology. The percentage of positive HAV samples in urban sewage fell from 57.4% to 3.1% in 5–10 years in the two studied areas in Spain. Around 30% of the urban sewage samples were positive for HEV in the absence of agricultural sources of contamination. HEV RNA was also detected in four clinical cases of acute hepatitis. The dramatic reduction in the presence of HAV in raw urban sewage observed in eastern Spain could be most likely related to the general improvement in sanitation. However, these improvements would not have an equivalent effect on the circulation of HEV and this observation could be explained by the presence of animal reservoirs for HEV, which act as external sources of infections.     

Monitoring the hepatitis A virus in urban wastewater from Rio de Janeiro, Brazil

Hepatitis A is a viral disease with a significant public health impact, especially in developing countries. Improvements in sewage services could prevent hepatitis A virus (HAV) dissemination into the environment and minimize the risk of infection. The aim of this study was to monitor HAV for one year in urban sewage samples from the largest wastewater treatment plant in Rio de Janeiro, Brazil, to assess environmental contamination with HAV and its dissemination after treatment by an activated sludge process. For this purpose, 48 samples (24 raw sewage samples and 24 treated effluent samples) were collected from August 2009 to July 2010 for HAV detection. Using quantitative real-time PCR 14 (58%) raw sewage samples were positive for HAV, and the highest viral genome loads were detected in the spring and summer. HAV was not detected in treated effluent samples, which suggests that the viral loads observed could be easily removed by the activated sludge process, thus preventing the dissemination of HAV into the environment. All of the HAV strains sequenced belonged to subgenotype IA, which clustered closely with Brazilian and Argentine HAV strains. These data demonstrate that environmental monitoring can be a useful tool in epidemiological studies.     

Prevalence of hepatitis A virus infection among sewage workers in Singapore.

To determine whether or not occupational exposure to sewage is associated with a higher seroprevalence of hepatitis A virus (HAV) infection, 600 sewage workers in Singapore were tested for total (IgG and IgM) antibody to HAV by enzyme immunoassay. Using logistic regression with stepwise procedure, the adjusted seroprevalence of sewage workers was 2.2 times higher than that of another non-occupationally exposed population group. Seroprevalence was significantly correlated with age and educational levels, the association being independent of the occupational association. The epidemiological data in the study show that sewage workers have an increased occupational risk of acquiring HAV infection and should be protected by active immunization.     

Need for vaccination of sewer workers against leptospirosis and hepatitis A.

OBJECTIVES--This study compared the prevalence of Leptospira interrogans and hepatitis A virus (HAV) antibodies in serum samples from sewer workers and controls. METHODS--A blood sample was obtained from 76 of the 101 municipal sewer workers (75%) of Quebec City and from two controls matched to each for age and sex. Testing was done for antibodies against serovars of Leptospira icterohaemorragiae, bratislava, hardjo, grippotyphosa, and kennewicki (pomona) and hepatitis A. RESULTS--Sewer workers had a greater prevalence of antibodies against leptospirosis than controls (12% v 2%, P = 0.003). In contrast, antibodies to HAV were not significantly more prevalent among workers than among controls (54% v 49%, P = 0.51). Prevalence of HAV antibodies increased significantly with age both among workers and controls (chi 2 for trend, P < 0.001). In contrast with younger workers, prevalence of HAV antibodies was greater among workers > or = 40 years than among their controls (81% v 65%, P = 0.04). CONCLUSION--Leptospirosis continues to be a problem to sewer workers but hepatitis A is apparently no longer a risk. The likely explanation is that leptospira are still abundant in the sewage system in contrast with HAV, which is only rarely to be found in sewage as a result of the generalised decrease in incidence of hepatitis A in the past three decades. The decision to vaccinate sewer workers against hepatitis A should take into account that it is impossible to avoid all contact with sewage fluid and, despite the fact that the actual incidence of hepatitis A is low, there is a real possibility of sporadic exposure during a future outbreak.     

Environmental surveillance. An additional/alternative approach for virological surveillance in Greece?

The detection of viruses in the sewage of an urban city by nucleic acid amplification techniques allows the identification of the viral strains that are circulating in the community. The aim of the study was the application of such detection which gives useful data on the distribution, spread, and frequency of these viruses, supporting epidemiological studies of the related viral infections. A two year (2007-2009) survey was conducted in order to evaluate the presence of human adenoviruses (hAdV), hepatitis A viruses (HAV), hepatitis E viruses (HEV), noroviruses (NoV), and human polyomaviruses (hPyV) in sewage samples collected from the inlet of a municipal biological wastewater treatment plant located in southwestern Greece. PCR methods were used for this survey. In total, viruses have been detected in 87.5% (42/48) of the analyzed sewage samples. Analytically, DNA viruses, hAdVs and hPyVs have been detected in 45.8% (22/48) and 68.8% (33/48) of the samples, respectively. As it concerns RNA viruses, HAV was detected in 8.3% (4/48), NoVs in 6.3% (3/48), while HEV has not been detected at all. After sequencing, AdVs were typed as Ad8, Ad40 and Ad41, while both JC and BK hPyVs have been recognized. All NoVs have been identified as GII4, while HAV was typed as genotype IA. Similar long-term studies could be undertaken in countries such as Greece in order to offer a valuable and complementary tool to current problematic epidemiological surveillance systems. This study demonstrates the advantages of environmental surveillance as a tool to determine the epidemiology of viruses circulating in a given community. To our knowledge this was the first of its kind study performed in Greece in order to establish this new way of surveillance.     

Seroprevalence of hepatitis A virus infection among sewage workers in the Parisian area, France

Sewers are an ideal environment to be occupationally exposed to viral hepatitis A (HAV) infection, because of high frequency and ability of the virus to remain viable for prolonged periods in sewage. However, data on the occupational risk of HAV infection among sewage workers is not well documented. In a cross sectional study comparing sewage workers (n = 155) to those not occupationally exposed to it (n = 70), we found a non significant increase in HAV seropositivity among sewage workers of 12.9% (p = 0.07). The prevalance of HAV antibody was significantly associated with duration of occupational exposure to sewage (p < 0.015), stay in HAV endemic areas (p < 0.03), age (p < 0.001), and number of siblings (p < 0.03). A stepwise logistic regression analysis gave an adjusted odds ratio for HAV seropositivity 2.15 fold greater in sewage workers compared to those not occupationally exposed to it. So, although there was no significant difference in the prevalance of HAV antibody between sewage workers and others, exposure to sewage was an independent risk factor for HAV seropositivity, and this raises the question of whether it is necessary to vaccinate sewage workers against viral hepatitis A.     

甲型肝炎病人粪便排出甲肝病毒的规律

本研究用EIA对62例甲肝病人的82份粪便进行了检测。发病前1~15天8份粪便,7份HAV阳性(87.50%),发病前16天以上2份粪便均为阴性。发病后1~7天阳性率为42.86%(6/14),8~15天为13.33%(6/45),16天以上13份,无一份阳性。对4名病人的19份系列粪便标本检测HAV表明,发病前1~15天粪便中HAV滴度最高(P/N=16.2±0.60),发病后急剧下降,至发病后第2周刚刚高于EIA的灵敏度(P/N=4.1±0.78)。     

Prevalence of hepatitis A virus infection in sewage plant workers of Central Italy: is indication for vaccination justified?

Prevalence of antibodies to hepatitis A virus (HAV) was studied in a group of 65 sewage plant workers living in Tuscany, Central Italy. In order to evaluate the effect of several confounders (age, place of birth, income, educational degree, sea-food consumption, etc.), subjects under study were matched with 160 other workers residing in the same area. Anti-HAV was detected in about 51% of sewage workers and 44% of other employees. The difference was not statistically significant. Both univariate and multivariate analysis showed that the main variables related to previous HAV infection were increasing age (P<0.001), birth in Southern Italy (P<0.01) and lower educational degree (P<0.001). Although other studies in Northern and Central Europe showed a slightly higher risk of infection in sewage workers versus general population, lack of evidence of occupational risk in Italy might be explained by the relative importance of a higher degree of viral circulation in the past. The changing epidemiology of HAV infection in Italy with increasing numbers of susceptibles in adults and the potential occupational risk suggest that the present indication to immunize sewage plant workers against hepatitis A should be maintained.     

氯对甲型肝炎病毒抗原性及核酸多态性影响的研究

为了探讨氯灭活甲型肝炎病毒 (HAV)的机制 ,采用酶联免疫吸附试验和RNA的随机引物扩增指纹图谱技术分别检测在氯灭活HAV前后病毒抗原以及核酸多态性的变化。结果显示 :灭活病毒的感染性(加氯 10mg L或 2 0mg L接触 30min)先于破坏病毒的抗原性 (加氯 10mg L或 2 0mg L接触 6 0min) ,当病毒感染性被灭活时 ,往往可以看到病毒核酸多态性的变化。结果表明 :氯灭活HAV可能是通过破坏核酸局部片段所致。