Age-specific antibody prevalence to hepatitis A in England: implications for disease control.

Sera from an age-stratified sample of 7196 individuals, submitted for diagnostic purposes to four public health laboratories in England in 1986/7, were tested for hepatitis A antibody. The serological profiles, which showed marked regional differences, were consistent with declining incidence in the past. The decline in the incidence of hepatitis A has resulted in an increase in susceptibility in adults. This has three main consequences: an increase in the average age of infection may be leading to an increase in morbidity; normal immunoglobulin may become less protective against hepatitis A; the risk of transmission through blood products contaminated by viraemic blood donors may rise. Current average annual incidence in 5-14-year olds was estimated to vary between regions from 0.5-1.9%. This supports the view that, in the absence of a vaccination programme, hepatitis A will remain endemic unless there are further improvements in living conditions and standards of hygiene. A vaccine giving long-lasting protection could eliminate hepatitis A transmission with modest coverage at a young age. Targeting childhood vaccination on economically deprived areas or using vaccine to control outbreaks might be more effective policies.     

Age-specific human papillomavirus antibody and deoxyribonucleic acid prevalence: a global review

PurposeGlobal data on human papillomavirus (HPV) serological and deoxyribonucleic acid (DNA) prevalence are essential to optimize HPV prophylactic vaccination strategies.MethodsWe conducted a global review of age-specific HPV antibody and studies with both antibody and DNA prevalence for HPV-16, ?18, ?6, and ?11.ResultsOne hundred seventeen studies were included; participants' ages ranged from several hours to >90 years. HPV-16 seroprevalence was generally higher in Africa, Central and South America, and North America, more prevalent among women than among men, and peaked around ages 25–40 years. HPV-18 seroprevalence was generally lower than HPV-16 with a later age peak. Data were limited for HPV-6 and ?11, both of which peaked at ages similar to HPV-18. Among 9–26-year-old females, HPV-16 seroprevalence ranged from 0%–31% in North America, 21%–30% in Africa, 0%–23% in Asia/Australia, 0%–33% in Europe, and 13%–43% in Central and South America. HPV-16/-18 DNA prevalence peaked 10–15 years before corresponding HPV-16/-18 antibody prevalence.ConclusionsFemales within the HPV vaccine-eligible age-group (9–26 years) had a range of dual HPV-16 DNA and serology negativity from 81%–87%, whereas 90%–98% were HPV-16 DNA negative. Serology and DNA data are lacking worldwide for females younger than age 15 years, the prime target group for vaccination.     

Reduction in hepatitis A antibody prevalence among young adults in Israel.

BACKGROUND: Hepatitis A (HAV) is endemic in Israel. A number of developed countries have reported marked reductions in prevalence of antibodies. The objective of this study was to determine whether change in prior infection took place over a 7-year period and to investigate the sociodemographic characteristics of infection in Israel. METHODS: Recruitment into military service in Israel at the age of 18 is compulsory. Representative samples of male recruits were selected in 1977 and 1984. Antibodies to HAV were tested by solid phase radioimmunoassay in the 1977 sample and by an enzyme immunoassay in the 1984 sample. RESULTS: HAV antibody prevalence in 1977 was 69% (95% confidence interval (CI) 65% to 72%) versus 54% (95% CI 49% to 59%) in 1984 (p < 0.0001). The reduction was evident in all ethnic-origin groups comprising the Jewish population. In 1984 the prevalence was 28% for Jewish men of European origin, 60% for Asian origin, and 80% for the North African origin group. A statistically significant independent effect of education was evident. CONCLUSIONS: These findings point to a reduction in feco-oral transmission and hepatitis A virus infection in childhood in Israel, yet reveal considerable continuing ethnic and educational inequalities in prior exposure to infection. A potential for large outbreaks exists during transition from high to low endemicity, particularly in high-risk military populations. These populations are candidates for application of active hepatitis A vaccines now undergoing testing.     

An outbreak of infectious hepatitis investigated using radioimmunoassays for hepatitis A virus antibody

An outbreak of suspected infectious hepatitis in a primary school was investigated using sensitive diagnostic methods for hepatitis A. A total of 116 sera from children were tested for the presence of both IgM and IgG antibodies to hepatitis A (HAV). The results were compared to those obtained for samples from a control school. IgG antibodies were present in 45% and 10% of the children in the outbreak and control schools respectively.     

The study transplacental chikungunya virus antibody kinetics, Thailand

Antibodies to chikungunya virus were detected by hemagglutination-inhibition assay in 33.6% of 2,000 infants' cord sera at delivery. Follow-up of 24 seropositive infants showed that the half-life of antibody persistence was 35.5 days. Chikungunya virus infection is common in Thailand, and routine use of diagnostic assays is needed.     

Ebola virus antibody prevalence in dogs and human risk

During the 2001-2002 outbreak in Gabon, we observed that several dogs were highly exposed to Ebola virus by eating infected dead animals. To examine whether these animals became infected with Ebola virus, we sampled 439 dogs and screened them by Ebola virus-specific immunoglobulin (Ig) G assay, antigen detection, and viral polymerase chain reaction amplification. Seven (8.9%) of 79 samples from the 2 main towns, 15 (15.2%) of 99 samples from Mekambo, and 40 (25.2%) of 159 samples from villages in the Ebola virus-epidemic area had detectable Ebola virus-IgG, compared to only 2 (2%) of 102 samples from France. Among dogs from villages with both infected animal carcasses and human cases, seroprevalence was 31.8%. A significant positive direct association existed between seroprevalence and the distances to the Ebola virus-epidemic area. This study suggests that dogs can be infected by Ebola virus and that the putative infection is asymptomatic.     

An outbreak of infectious hepatitis investigated using radioimmunoassays for hepatitis A virus antibody.

An outbreak of suspected infectious hepatitis in a primary school was investigated using sensitive diagnostic methods for hepatitis A. A total of 116 sera from children were tested for the presence of both IgM and IgG antibodies to hepatitis A (HAV). The results were compared to those obtained for samples from a control school. IgG antibodies were present in 45% and 10% of the children in the outbreak and control schools respectively.     

Prevalence of hepatitis A virus antibody among Navajo school children.

Previous studies of the prevalence of immunity to hepatitis A (anti-HAV) in the United States have used urban settings or institutions for the mentally handicapped. In a rural setting among normal children, a serologic investigation of prevalence of anti-HAV was conducted in a boarding school adjacent to the Navajo reservation. The results show rates of anti-HAV that are the highest reported at the ages tested in any subpopulation in the United States, comparable only with those in developing countries.     

The prevalence of hepatitis B core antibody in vaccinated Chinese children: A hospital-based study

Background & aims

After nearly 30?years of immunization, there is little known about the prevalence of hepatitis B core antibody (anti-HBc) in Chinese children. The clinical significance of anti-HBc would be more and more important. In this study, we had tried to analyse the prevalence of anti-HBc in vaccinated Chinese children, exploring the post-immunization status based on a large sample sized investigation.

Prevalence of antibody to hepatitis A virus in Okinawa and Kyushu, Japan

Between 1968 and 1981, a total of 1955 serum samples from healthy subjects chosen at random in seven districts of Okinawa and two districts of Kyushu were surveyed for antibody to hepatitis A virus (anti-HAV) by radioimmunoassay. Overall prevalence of anti-HAV was 55.1% in Okinawa and 35.9% in Kyushu. Prevalence of less than 10% was observed in subjects less than or equal to 14 years of age in Okinawa and less than or equal to 24 years of age in Kyushu. In three of the districts of Okinawa, second serum samples were collected after intervals of eight, 10, and 12 years, respectively. Overall prevalence of anti-HAV decreased significantly over these time periods. When the age-specific prevalence of anti-HAV on the first occasion is compared with that on the second occasion, it can be seen that there have been few new cases of hepatitis A infection. These data suggest that hepatitis A infection among children has declined dramatically in recent years, and that young people may be highly susceptible to hepatitis A virus.     

静脉注射毒品人群中HIV、HBV和HCV感染的现况研究

目的了解静脉注射毒品人群中人类免疫缺陷病毒（HIV）、乙型肝炎病毒（HBV）和丙型肝炎病毒（HCV）的感染情况。方法从四川、湖南、广西和新疆等地静脉注射毒品人群中采集血液样本2025份，应用酶联免疫试剂盒检测抗-HIV、抗-HCV抗体和HBsAg。结果红静脉沣射毒品人群中，抗-HIV、抗-HCV及HBsAg的阳性率分别为14．7％～30．4％、60．7％～85．5％和6．6％～22．4％，其HIV／HBV、HIV/HCV、HCV／HBV和HIV／HCV／HBV合并感染率分别为0％～0．4%、11．6％～27．2％、2．3％～14．3％和1．6％～4．8％。结论静脉注射毒品人群中HIV、HBV和HCV的感染率均高于正常人群，其中HIV与HCV合并感染率最高。     

Shifts in the rates and levels of antibody to hepatitis A virus associated with hepatitis A infection in children's communities

In order to investigate the shift in the rates and levels of antibody to hepatitis A virus, 567 children in 20 isolated groups of five day-care centers were observed over a period of 8 months during which the seasonal rise in hepatitis A morbidity occurs. Increases in the proportion of seropositive ranging from 5 to 37% were demonstrated in 6 groups, and were always associated with the occurrence of either overt or sub-clinical hepatitis A infection. High rates of seropositivity were also noted in the groups in which cases of hepatitis A had been registered prior to the period of observation. In some children with low and medium antibody levels, antibody titres showed further increases after reinfection. A substantial part of children retained low antibody titres during the entire period of observation, and eight previously sero-negative children developed low antibody levels after asymptomatic hepatitis A infections. In one group the spread of hepatitis A infection (clinical and asymptomatic) was prevented by the administration of commercially available immunoglobulin immediately after the discovery of an infected food handler. Passive antibodies were found in previously sero-negative children, and these antibodies dropped to undetectable levels two months after administration.     

Etiological spectrum of viral hepatitis and prevalence of markers of hepatitis A and B virus infection in north India

The etiological spectrum of viral hepatitis and the prevalence of serological markers of hepatitis A and B virus infection in healthy persons in north India were studied. Hepatitis A virus was found to be the most common cause of acute hepatitis in children (67%). It was a less frequent cause of this disease in adults (14%). Hepatitis A virus was only rarely the cause of acute (12%) and subacute (4%) liver failure. It was recorded as the etiological agent in an epidemic among schoolchildren. Exposure to hepatitis A virus occurs in early childhood, and by the age of 10 years, 90% of healthy persons have serological evidence of hepatitis A virus infection.     

Global prevalence of occult hepatitis C virus: A systematic review and meta-analysis

BACKGROUNDOccult hepatitis C infection (OCI) is characterized by the presence of hepatitis C virus (HCV) RNA in the liver, peripheral blood mononuclear cells (PBMC) and/or ultracentrifuged serum in the absence of detectable HCV-RNA in serum. OCI has been described in several categories of populations including hemodialysis patients, patients with a sustained virological response, immunocompromised individuals, patients with abnormal hepatic function, and apparently healthy subjects.AIMTo highlight the global prevalence of OCI.METHODSWe performed a systematic and comprehensive literature search in the following 4 electronic databases PubMed, EMBASE, Global Index Medicus, and Web of Science up to 6th May 2021 to retrieve relevant studies published in the field. Included studies were unrestricted population categories with known RNA status in serum, PBMC, liver tissue and/or ultracentrifuged serum. Data were extracted independently by each author and the Hoy et al tool was used to assess the quality of the included studies. We used the random-effect meta-analysis model to estimate the proportions of OCI and their 95% confidence intervals (95%CI). The Cochran''s Q-test and the I² test statistics were used to assess heterogeneity between studies. Funnel plot and Egger test were used to examine publication bias. R software version 4.1.0 was used for all analyses.RESULTSThe electronic search resulted in 3950 articles. We obtained 102 prevalence data from 85 included studies. The pooled prevalence of seronegative OCI was estimated to be 9.61% (95%CI: 6.84-12.73) with substantial heterogeneity [I² = 94.7% (95%CI: 93.8%-95.4%), P < 0.0001]. Seropositive OCI prevalence was estimated to be 13.39% (95%CI: 7.85-19.99) with substantial heterogeneity [I² = 93.0% (90.8%-94.7%)]. Higher seronegative OCI prevalence was found in Southern Europe and Northern Africa, and in patients with abnormal liver function, hematological disorders, and kidney diseases. Higher seropositive OCI prevalence was found in Southern Europe, Northern America, and Northern Africa.CONCLUSIONIn conclusion, in the present study, it appears that the burden of OCI is high and variable across the different regions and population categories. Further studies on OCI are needed to assess the transmissibility, clinical significance, long-term outcome, and need for treatment.     

Modeling the hepatitis A epidemiological transition in Thailand

BackgroundIn most low- and middle-income countries, hepatitis A virus (HAV) is shifting or expected to shift from high endemicity to intermediate or low endemicity. A decreased risk of HAV infection will cause an increase in the average age at infection and will therefore increase the proportion of infections that results in severe disease. Mathematical models can provide insights into the factors contributing to this epidemiological transition.MethodsAn MSLIR compartmental dynamic transmission model stratified by age and setting (rural and urban) was developed and calibrated with demographic, environmental, and epidemiological data from Thailand. HAV transmission was modeled as a function of urbanization and access to clean drinking water. The model was used to project various epidemiological measures.ResultsThe age at midpoint of population immunity remains considerably younger in rural areas than in urban areas. The mean age of symptomatic hepatitis A infection in Thailand has shifted from childhood toward early adulthood in rural areas and is transitioning from early adulthood toward middle adulthood in urban areas. The model showed a significant decrease in incidence rates of total and symptomatic infections in rural and urban settings in Thailand over the past several decades as water access has increased, although the overall incidence rate of symptomatic HAV is projected to slightly increase in the coming decades.ConclusionsModeling the relationship between water, urbanization, and HAV endemicity is a novel approach in the estimation of HAV epidemiological trends and future projections. This approach provides insights about the shifting HAV epidemiology and could be used to evaluate the public health impact of vaccination and other interventions in a diversity of settings.     

淮安市戊型病毒性肝炎人畜共患性及病毒基因型研究

目的探讨淮安市戊型病毒性肝炎病例与猪之间的联系,为控制HEV在人畜间的传播提供依据。方法在淮安市收集急性戊肝、肝炎未分型病例血液标本193份,同期在屠宰场收集生猪胆囊标本510份,采用Real-time RT-PCR和RT-PCR提取目标核苷酸,测定序列后进行分析。结果所有标本共分离出HEV-4型毒株20株,分4个亚型,HEV-4d型为优势流行毒株亚型;人源与猪源HEV毒株间的同源性为:80.3%～97.7%。结论淮安市戊肝病例与生猪感染的HEV高度同源,生猪是戊肝传播过程中一种重要的动物宿主。