Virus Vaccination Coverage Research Articles

Influenza, COVID-19, and Respiratory Syncytial Virus Vaccination Coverage Among Adults - United States, Fall 2024.

The Advisory Committee on Immunization Practices (ACIP) recommends annual influenza and COVID-19 vaccination for all persons aged ≥6 months, including adults aged ≥18 years. ACIP also recommends a single lifetime dose of respiratory syncytial virus (RSV) vaccine for adults aged ≥75 years and for those aged 60-74 years who are at increased risk for severe RSV disease. Data from the National Immunization Survey-Adult COVID Module, a random-digit-dialed cellular telephone survey of U.S. adults aged ≥18 years, are used to monitor influenza, COVID-19, and RSV vaccination coverage. By the week ending November 9, 2024, an estimated 34.7% of adults aged ≥18 years reported having received an influenza vaccine, and 17.9% reported having received a COVID-19 vaccine for the 2024-25 respiratory virus season; 39.7% of adults aged ≥75 years, and 31.6% of adults aged 60-74 years at increased risk for severe RSV, had ever received an RSV vaccine. Coverage varied by jurisdiction and demographic characteristics and was lowest among younger adults and those without health insurance. Although early season estimates indicate that many adults are unprotected from respiratory virus infections, many appeared open to vaccination: overall, approximately 35% and 41% of adults aged ≥18 years reported that they definitely or probably will receive or were unsure about receiving influenza and COVID-19 vaccines, respectively, and 40% of adults aged ≥75 years reported that they definitely or probably will receive or were unsure about receiving RSV vaccine. Health care providers and immunization programs still have time to expand outreach activities and promote vaccination to increase coverage in preparation for the height of the respiratory virus season. Using these data can help health care providers and immunization programs identify undervaccinated populations and understand vaccination patterns to guide planning, implementation, and evaluation of vaccination activities.

Development of a network model to implement the HPV vaccination coverage.

The vaccination coverage of a population is the usual indicator of the effectiveness of vaccination strategies. The study aims to evaluate the effectiveness of an organizational and communication network to implement Human Papilloma Virus (HPV) vaccination coverage both in males and females in the Center Tuscany Local Health Authority. Experimental study. In January 2022, a retrospective study was conducted on anti-HPV vaccine coverage (full cycle), of those born from 2007 to 2010, in the Empoli Territorial Area of Florence (240 thousand inhabitants) under the Center Tuscany Local Health Authority. In February 2022, a project (meetings with general practitioners and pediatricians, communication through local media, increased opening hours of vaccination clinics and continuous monitoring of vaccination status) started to recover the females and males non-compliant; in the first five months, in addition to guaranteeing the offer to the reference cohort, it aimed to recover the 2007, 2008 and 2009 cohorts, while in the following six months the anti-HPV vaccine offer was expanded for the 2010 cohort. In January 2022, for all cohorts the average total coverages were 49.2% (49.1% for females and 49.5% for males), while in December 2022 they were 63.9% (65.8% for females and 62.3% for males). Coverage increased by 15.6% (+14.2% for females and +16.8% for males) for the 2007 birth cohort, by 22.3% (+20.6% for females and +23.7% for males) for the 2008 cohort and by 20.9% (+31.4% for females and +10.6% for males) for the 2009 cohort. This model in force in the whole Center Tuscany Local Health Authority for a few years and already activated in the previous Local Health Authority of Empoli, now called Empoli Territorial Area, has allowed to implement the Human Papilloma Virus vaccine coverage for both genders.

Influenza, Updated COVID-19, and Respiratory Syncytial Virus Vaccination Coverage Among Adults - United States, Fall 2023.

During the 2023-24 respiratory virus season, the Advisory Committee on Immunization Practices recommends influenza and COVID-19 vaccines for all persons aged ≥6 months, and respiratory syncytial virus (RSV) vaccine is recommended for persons aged ≥60 years (using shared clinical decision-making), and for pregnant persons. Data from the National Immunization Survey-Adult COVID Module, a random-digit-dialed cellular telephone survey of U.S. adults aged ≥18 years, are used to monitor influenza, COVID-19, and RSV vaccination coverage. By December 9, 2023, an estimated 42.2% and 18.3% of adults aged ≥18 years reported receiving an influenza and updated 2023-2024 COVID-19 vaccine, respectively; 17.0% of adults aged ≥60 years had received RSV vaccine. Coverage varied by demographic characteristics. Overall, approximately 27% and 41% of adults aged ≥18 years and 53% of adults aged ≥60 years reported that they definitely or probably will be vaccinated or were unsure whether they would be vaccinated against influenza, COVID-19, and RSV, respectively. Strong provider recommendations for and offers of vaccination could increase influenza, COVID-19, and RSV vaccination coverage. Immunization programs and vaccination partners are encouraged to use these data to understand vaccination patterns and attitudes toward vaccination in their jurisdictions to guide planning, implementation, strengthening, and evaluation of vaccination activities.

PARNAS: Objectively Selecting the Most Representative Taxa on a Phylogeny.

The use of next-generation sequencing technology has enabled phylogenetic studies with hundreds of thousands of taxa. Such large-scale phylogenies have become a critical component in genomic epidemiology in pathogens such as SARS-CoV-2 and influenza A virus. However, detailed phenotypic characterization of pathogens or generating a computationally tractable dataset for detailed phylogenetic analyses requires objective subsampling of taxa. To address this need, we propose parnas, an objective and flexible algorithm to sample and select taxa that best represent observed diversity by solving a generalized k-medoids problem on a phylogenetic tree. parnas solves this problem efficiently and exactly by novel optimizations and adapting algorithms from operations research. For more nuanced selections, taxa can be weighted with metadata or genetic sequence parameters, and the pool of potential representatives can be user-constrained. Motivated by influenza A virus genomic surveillance and vaccine design, parnas can be applied to identify representative taxa that optimally cover the diversity in a phylogeny within a specified distance radius. We demonstrated that parnas is more efficient and flexible than existing approaches. To demonstrate its utility, we applied parnas to 1) quantify SARS-CoV-2 genetic diversity over time, 2) select representative influenza A virus in swine genes derived from over 5 years of genomic surveillance data, and 3) identify gaps in H3N2 human influenza A virus vaccine coverage. We suggest that our method, through the objective selection of representatives in a phylogeny, provides criteria for quantifying genetic diversity that has application in the the rational design of multivalent vaccines and genomic epidemiology. PARNAS is available at https://github.com/flu-crew/parnas.

Assessment of Hepatitis B Vaccination Status and Associated Factors among Healthcare Workers in Bosaso, Puntland, Somalia 2020.

Introduction Hepatitis B virus disease is a viral infection caused by the hepatitis B virus (HBV), which is a major public health problem worldwide. According to the World Health Organization (WHO) estimate, two billion people worldwide have serologic evidence of past or present HBV infection. The risk of infection is high among health professionals due to the risk of occupational contact with fluids of infected patients and the risk of needle stick injury. This study is aimed at assessing HBV vaccination coverage and reasons for possible defiance of the vaccine among healthcare workers in Bosaso, Somalia. Methodology. An institution-based cross-sectional study was conducted by using a quantitative approach to identify hepatitis B virus vaccination coverage and reasons for vaccine defiance in Bosaso from September 2020 to November 2020. Healthcare workers (HCWs) in Bosaso city both in public and private health facilities who accepted to participate in this study were interviewed by using a structured questionnaire, and SPSS was used to analyze the collected data. Results We found that only (16.4%) of HCWs were fully vaccinated. The main reasons for not taking the vaccine by the participants were the unavailability of the vaccine (42%), high vaccine cost (28.7%), lack of time (20.7%), and fear of vaccine side effects (7.5%). The majority (69.7%) of HCWs demonstrated good knowledge about HBV infection. The vaccination uptake was significantly higher among midwives (p = 0.02; OR = 1.21; 95%CI = 1.39 − 67.41) and individuals aged under 30 years (p = 0.03; OR = 8.6; 95%CI = 1.17–63.26). Conclusion Our study revealed that vaccination coverage of HCWs in Bosaso was very low because of the unavailability of vaccines, high cost of the vaccine, lack of time, and fear of vaccine side effects. Therefore, the development and implementation of policies related to HBV vaccination are recommended.

Uptake of Cost-Free Hepatitis B Vaccination among Healthcare Workers in Northern Tanzania

Background The World Health Organization and other global agencies recommend all healthcare workers (HCWs) to get vaccinated against hepatitis B virus before enrolment to clinical work. There are limited data in low-income countries on hepatitis B virus vaccination coverage among HCWs, which set back WHO Hepatitis B Elimination Strategy 2016-2021. The aim of this study was to determine the prevalence of hepatitis B virus vaccination uptake and associated factors among HCWs from a tertiary and teaching hospital in northern Tanzania. Methods A cross-sectional study was conducted among HCWs at Kilimanjaro Christian Medical Centre a referral and teaching hospital from August 2016 to June 2017. Questionnaire based interviews were used to obtain information about HCWs’ demographic characteristics, occupation risks and other invasive procedures such as intravenous, and intramuscular injections and knowledge of Hepatitis B Virus (HBV) infection. Multivariable logistic regression was used to determine factors associated with Engerex DNA-recombinant hepatitis B vaccine uptake. Results About two third 295 (67.4%) of 438 participants had received HBV vaccination. Among those who ever received HBV vaccination (n=295), 205 (70.5%) received 3 shots, 57 (19.5%) received 2 shots and 33 (10%) received 1 shot. HCWs working in clinical areas had 79% higher odds of vaccine uptake compared to those who were not (OR=1.79, 95%CI 1.11, 2.89). Ever having intravenous and intramuscular injections significantly increased the odds of vaccination uptake compared to those who never had (OR=2.21, 95%CI 1.33, 3.66) and (OR=2.42, 95%CI 1.36, 4.28) respectively. Also, HCWs with a fair and good knowledge on HBV infection had over three times higher odds of vaccine uptake compared to those with poor knowledge (OR=3.08, 95%CI 1.90, 5.01) and (OR=3.07, 95%CI 1.75, 5.40), respectively. After adjusting for other factors, those that remained to be significantly associated with HBV vaccine uptake were area of specialty and knowledge on HBV infection. Conclusion The current Engerex DNA-recombinant hepatitis B vaccine coverage among HCWs at KCMC, referral and teaching hospital in North-eastern Tanzania was only 67.4% despite of it been given free of charge. Factors that were associated with HBV vaccine uptake include area of specialty and knowledge of participants on HBV infection and vaccination. We encourage continuous medical education among HCWs about importance of hepatitis B vaccination. We also recommend hepatitis B vaccination as pre-employment requirement for HCWs as well as doing antibody titer determination post vaccination. Keywords: Cost-free hepatitis B vaccine, Prevention, Healthcare workers, vaccination coverage, Low income countries, Tanzania.

Full-dose hepatitis B virus vaccination coverage and associated factors among health care workers in Ethiopia: A systematic review and meta-analysis.

IntroductionThe hepatitis B vaccine is the backbone of hepatitis B prevention. All health care workers must receive a full-dose (3-dose vaccine series) to achieve >90% protection against hepatitis B virus. There is limited evidence available on vaccination coverage of HBV among health care workers in Ethiopia. Therefore, the objective of this study was to estimate the national full-dose hepatitis B vaccination coverage and the associated factors among health care workers in Ethiopia.MethodsStudies were retrieved from PubMed, EMBASE, Web of Science, SCOPUS, CINAHL, and Google Scholar by using a combination of search terms with Boolean operators. The quality of each study was evaluated independently by three authors using the modified Newcastle-Ottawa Scale (NOS) for cross-sectional studies. Statistical analyses were performed using STATA™ Version 14 software. Meta-analysis was carried out using a random-effects (DerSimonian and Laird) method. The heterogeneity test was conducted by using I-squared (I2) statistics. Leave-one-out sensitivity analysis was performed.ResultsA total of 15 articles with 5734 participants were included in this systematic review and meta-analysis. The pooled prevalence of full-dose hepatitis B virus vaccination coverage among health care workers in Ethiopia was 20.04% (95% CI: 13.83, 26.26); I2 = 98.9%). Being male sex (p = 0.002), having work experience of less than 5 years (p < 0.001), educational level of diploma and below (p = 0.003), health care providers who received training on infection prevention (p < 0.001), and those who had a history of exposure to blood and body fluids (p = 0.001), were factors significantly associated with full-dose hepatitis B virus vaccination.ConclusionThe national full-dose hepatitis B vaccination coverage among health care workers was low. Training of health care workers in infection prevention, particularly in hepatitis B and testing and providing hepatitis B vaccination for newly recruited staff and every 5 years for those long-term workers were recommended to increase the uptake of the vaccine.

Prevalence of diarrhoea and child care practices among under-five children in tea gardens of Jorhat district, Assam

Background: Globally diarrhoea remains the second leading cause of mortality among children of below five years age. Objective was to find out the prevalence of diarrhoea and child care practices associated with diarrhoea in under five children of tea garden workers of Jorhat district, Assam.Methods: A community based cross sectional study was conducted among the under five children of selected tea gardens of Jorhat district of Assam, India from July 2017 to June 2018.Results: Prevalence of diarrhoea among the study participants in last 2 weeks was found to be 26.4%. Out of 315 study participants, 24.1% belonged to the age group of 12-24 months, 55.2% were males. Exclusive breast feeding was recorded in 95.9% of the children. Prevalence of diarrhoea was less among exclusively breast fed children 25.5% as compared to not exclusively breastfed 46.1%. Health advice during diarrhea was sought by 97.8% of the respondents. Available records showed almost all of the children 99.3% got vaccinated with measles vaccine and contrary to this majority 64.4% study participants had not received Rota virus vaccination.Conclusions: Diarrhoea is still a significant public health problem among fewer than five children of tea garden workers with low Rota virus vaccine coverage. Our study findings recommends for the awareness building among the tea garden dwellers in regard to hand hygiene, timely initiation of complementary feeding, importance of vaccinating children with Rota virus vaccine as a part of containment programme.

Why human papilloma virus vaccination coverage is low among adolescents in the US? A study of barriers for vaccination uptake.

Introduction:Cervical cancer and Human papillomavirus (HPV) affects women, men, and children of all races, ethnicities, and backgrounds. The objective of this study is to examine the association between adolescent (13–17 years) HPV vaccination uptake and the key factors influencing the uptake rates of HPV vaccination.Materials and Methods:The 2016 NIS-Teen data, an annual survey conducted by the CDC to monitor vaccination uptake in the United States is used for this study. Multivariable logistic regression model was used to estimate the relationship between various factors and HPV vaccine uptake.Results:Male adolescents were 0.26 times less likely to get the HPV vaccines; adolescents covered by private health insurance were 0.18 times less likely to get HPV vaccines; Hispanic adolescents were 1.47 times more likely, adolescents from other races including Asians were 1.75 times more likely to get vaccinated for HPV compared to non-Hispanic white adolescents. Adolescents from the low-income families were 1.21 times more likely to get vaccinated for HPV; adolescents from North-eastern regions of the United States were 1.62 times more likely to get vaccinated; adolescents who were not recommended for vaccination by the family physicians were 0.43 times less likely to get HPV vaccination; adolescents who did not have any safety concerns and concerns about side effects were 3.24 times more likely to get the HPV vaccine; adolescents from households that did have not orthodox religious beliefs were 13.67 times more likely to get vaccinated.Conclusions:Vaccination uptake rates are low for adolescents in the US and the results of this study identified important barriers which need to be addressed in order to improve vaccine uptake rates among the target groups which are less likely to get vaccinated. Also, knowing the sociodemographic and community level factors associated with HPV vaccination uptake status, health planners can better plan strategies to improve HPV vaccination in their local settings.

Immigration, screening, and cervical cancer incidence: an application of Age-Period-Cohort analysis.

Cervical cancer (CC) control is based on the implementation of effective screening programs. In the coming years, human papilloma virus vaccination coverage will contribute considerably toward cancer prevention. In Italy, where an organized screening program has been implemented, immigration from low/middle-income countries with a high prevalence of human papilloma virus infections has increased steadily over the last decades. To assess the impact of screening efforts in counteracting background changes, we analyzed the incidence trends of cervical intraepithelial neoplasia grade 3 carcinomas in situ (CIS) and invasive CC from 1994 to 2013 through an Age–Period–Cohort model using data of a regional population-based registry. Moreover, using Joinpoint regression, we compared the incidence of cervical lesions in native women with that observed in foreign-born women, highlighting the differences in age and screening status. The results indicate that the CC incidence trend decreased in Italian women (annual percent change = −2.7*%, 95% confidence interval = −4.3; −1.1), but increased (APC = 12.2*%, 95% confidence interval = 7.6; 17.0) in immigrants. For CIS, incidence rates show a growing trend in both groups, especially in women born abroad. For cancer, no marked changes in period-specific incidence rate ratios were detected until around 2000, when we found a slight decrease, followed by an increase. For CIS, we estimate an important upward trend in cohort-specific risks. The favorable effect of screening in preventing an increase in CC incidence has been counteracted by the progressive increase in immigrants from high-risk countries, where it is of increasing relevance to extend the use of vaccination.

The Effectiveness of Text Message Reminder- Recalls on Human Papilloma Virus Vaccination Coverage in Georgia

The Effectiveness of Text Message Reminder- Recalls on Human Papilloma Virus Vaccination Coverage in Georgia

Hepatitis B Virus Vaccination Coverage in Medical, Nursing, and Paramedical Students: A Cross-Sectional, Multi-Centered Study in Greece.

Students of health professions are at high risk of hepatitis B Virus (HBV) infection during their clinical training. The aim of this cross-sectional, multi-centered study was to investigate the HBV vaccination coverage in Greek medical, nursing, and paramedical students, to look into their attitudes towards the importance of vaccines and to reveal reasons associated with not being vaccinated. A self-completed, anonymous questionnaire was distributed to 2119 students of health professions in Greece, during the academic year 2013–2014. The HBV vaccination coverage of students was high (83%), being higher among medical students (88.1%, vs. 81.4% among nursing and 80.1% among paramedical students; p < 0.001). The vast majority of them (95%) have been vaccinated during childhood. In addition, 30% of the unvaccinated students declared fear over HBV safety. Our results indicate that the healthcare students achieved higher reported immunization rates compared to the currently serving healthcare workers, but also to the students of the last decade. The fact that nursing and paramedical students have lower coverage figures underlines the importance of targeted interventions for the different subgroups of healthcare students in terms of educational programs and screening for HBV markers in order to increase HBV vaccination uptake.

G497(P) Human papilloma virus vaccination coverage rates in ‘looked after’ young women – another marker of health disadvantage?

Aims Vaccination of young women against human papilloma virus (HPV) has important health benefits, not least in reducing lifetime cervical cancer risk. Young women who are ‘looked after’ are a vulnerable group, known to face disadvantage in several areas, including in relation to their health. Are we able to achieve HPV coverage rates in this group comparable to the general population in order to safeguard their future health? We set out to study this in our own Health Board area. Methods We studied young women aged 12–18 years, ‘looked after’ by three Local Authorities co-terminus with our Health Board’s geographical area, who by virtue of their age should have received a 3 dose HPV vaccination course. We compared vaccination coverage in this group, using their recorded vaccination status on the All Wales Child Health Database, with a cohort of young women who were not ‘looked after’, and who had completed academic year 9 and were resident in the same Health Board area, using NPHS Wales ‘COVER’ data. We statistically analysed differences observed. We established that ethical approval was not required to undertake this study. Results Of 2555 young women who had completed year 9 and who were not ‘looked after’, 2308 had completed a 3 dose HPV vaccination course (90.3%). Of the 157 eligible young women ‘looked after’, 131 had received a comparable 3 dose vaccination course (83.4%). The difference was statistically significant (X2 7.763, p 0.005). Conclusion Our study of young women who should have completed a 3 dose HPV vaccination course highlights that those ‘looked after’ were significantly less likely to be vaccinated. We have identified yet another area of health disadvantage for this group which could have important consequences for their future health. Action is required to address this and our own recommendations will be discussed, in addition to what we see as the possible reasons for this difference. We suggest that HPV vaccination coverage rates in young women ‘looked after’ should be reviewed across the United Kingdom by those health professionals who work with this vulnerable group.

Inter-State Variation in Human Papilloma Virus Vaccine Coverage Among Adolescent Girls in the 50 US States, 2007

Human papilloma virus (HPV) vaccination could substantially reduce the burden of cervical cancer by preventing HPV infection. This study uses the 2007 National Survey of Children's Health (NSCH) to estimate HPV vaccine coverage prevalence for US girls aged 12-17, the target group for vaccination. NSCH is a population-based telephone survey of households with children younger than 18 years. The proportion of girls aged 12-17 whose parent or guardian reported receipt of a clinician recommendation for HPV vaccination, one or more does of HPV vaccine, or a complete three-dose HPV vaccine series were estimated. Multivariable models estimated adjusted associations and marginal predicted vaccine coverage prevalence for each of the 50 US states and according to race/ethnicity, household income, insurance status, parental education, and whether the girl had a 'medical home'. The NSCH sample included 17,264 girls aged 12-17. Overall 18.2 % (SE 0.8 %) of girls reportedly received at least one HPV vaccine dose and 3.6 % (SE 0.4 %) completed the series; 31 % received clinician recommendation for HPV vaccine. Girls who received a clinician recommendation to vaccinate were 23 (95 % CI 18-29) times as likely to be vaccinated as those not counseled. There was substantial interstate variation in vaccine coverage that was largely explained by variability in clinician counseling. For 2007, there was substantial variation in HPV vaccine coverage among US girls 12-17 years that was largely explained by variability in clinician counseling. Strategies aimed at increasing clinicians' counseling for HPV vaccination could substantially reduce disparities in HPV vaccine coverage.

Human Papilloma Virus Vaccination Coverage among Soldiers in a Military Treatment Facility, 2007-2010

Background: Human Papillomavirus (HPV) is the most common sexually transmitted infection (STI) among soldiers in the US Army. This study examines compliance patterns of female soldiers who receive the HPV prevention vaccine Gardasil in a Military Treatment Facility. Methods: Medical records of all female Soldiers aged 18 to 26 registered at Womack Army Medical Center (n = 3,186) were examined retrospectively. Patients identified with a Current Procedural Terminology (CPT) 90649, Human Papillomavirus (HPV) vaccine code encounter were included. Data were collected for all patients between November 1, 2006 and December 15, 2009. Results: Approximately 15% received Gardasil; of these only 37% completed the required 3-dose series. Conclusions: A number of recommendations to increase initiation of the vaccine series are suggested. Steps should also be taken to educate providers in using required annual physicals to start a discussion of the vaccine and to administer the first dose. To increase the visibility of the vaccine, this education could be completed at educational lectures, at residency lectures or at staff meetings within clinic areas. This study is intended to remind providers to initiate the HPV vaccine series and the importance of completing the entire series in all eligible females.

Influenza virus vaccination coverage is very low in Spanish children,

Influenza virus vaccination coverage is very low in Spanish children,

Meningococcal, influenza virus, and hepatitis B virus vaccination coverage level among health care workers in Hajj.

BackgroundThe objective of this study was to assess the compliance of health care workers (HCWs) employed in Hajj in receiving the meningococcal, influenza, and hepatitis B vaccines.MethodsA cross-sectional survey of doctors and nurses working in all Mena and Arafat hospitals and primary health care centers who attended Hajj-medicine training programs immediately before the beginning of Hajj of the lunar Islamic year 1423 (2003) using self-administered structured questionnaire which included demographic data and data on vaccination history.ResultsA total of 392 HCWs were studied including 215 (54.8%) nurses and 177 (45.2%) doctors. One hundred and sixty four (41.8%) HCWs were from Makkah and the rest were recruited from other regions in Saudi Arabia. Three hundred and twenty three (82.4%) HCWs received the quadrivalent (ACYW135) meningococcal meningitis vaccine with 271 (83.9%) HCWs receiving it at least 2 weeks before coming to Hajj, whereas the remaining 52 (16.1%) HCWs received it within < 2 weeks. Only 23 (5.9%) HCWs received the current year's influenza virus vaccine. Two hundred and sixty (66.3%) of HCWs received the three-dose hepatitis B vaccine series, 19.3% received one or two doses, and 14.3% did not receive any dose. There was no statistically significant difference in compliance with the three vaccines between doctors and nurses.ConclusionThe meningococcal and hepatitis B vaccination coverage level among HCWs in Hajj was suboptimal and the influenza vaccination level was notably low. Strategies to improve vaccination coverage among HCWs should be adopted by all health care facilities in Saudi Arabia.

Hepatitis B virus and hepatitis C virus infections in children

To analyse the most relevant recent information on efficacy, duration and coverage of anti-hepatitis B virus vaccination; correlates of mother-to-child hepatitis C virus transmission; the natural history and outcomes of hepatitis B and C virus infections in children; the efficacy and safety of specific therapies. Insufficient hepatitis B virus vaccine coverage and incomplete or delayed vaccine cycles need improvement in many countries. Hepatitis B virus mutants may explain some fulminant hepatitis in perinatally infected infants and vaccine failures. No interventions to prevent vertical hepatitis C virus transmission have been identified. Spontaneous clearance of hepatitis B is lower in children than in adults, while the rates appear to be similar for hepatitis C. The disease progression is slower for both infections in childhood. Several studies support the efficacy and safety of interferons and lamivudine in chronic hepatitis B or of interferons and ribavirin in chronic hepatitis C in children, but the optimal therapy remains unclear. There are doubts as to the long-term persistence of anti-hepatitis B immunization in low-endemicity areas. Routine hepatitis C virus testing in pregnancy is not recommended as there are no available prophylactic measures. Although hepatitis B and C virus infections are usually asymptomatic or with mild manifestations in childhood, concerns around their long-term clinical impact suggest the need for early treatment. Children should preferably be treated in the context of targeted trials for a better understanding of the efficacy and tolerance of drugs currently used in adults.

Prevalência e fatores associados a marcadores do vírus da hepatite B em população rural do Brasil central

To carry out a survey of hepatitis B virus seroepidemiology in a municipality in central Brazil, on the border of two large ecosystems, the cerrado (savanna) and the Amazon River basin. The municipality studied, Nova Mutum, is located in the north central portion of the Brazilian state of Mato Grosso. The study sample of 754 individuals included persons from families, selected at random, who were living in the municipality's urban center as well as all the individuals living in a nearby rural village. Ages ranged from 2 to 79 years. All eligible individuals were interviewed. Blood was collected and used to assess hepatitis B virus markers by enzyme-linked immunosorbent assay. Hepatitis B virus infection was found in 232 individuals, or 31% of them; 19 of them (3%) were HBsAg-positive. Of the 754 persons, 149 of them (20%) who reported having been vaccinated against hepatitis B and who presented anti-HBs positivity were classified as vaccine responders. With the multivariate analysis, the variables found to be associated with exposure to hepatitis B virus were having begun sexual relations, having been vaccinated against yellow fever with a needle-free jet injection gun (for the age group < 20 years), and being an immigrant from southern Brazil (> 20 years). Vaccine coverage was low among individuals older than 10 years. The largest share of susceptible individuals (74%) were found in the age group of 11 to 20 years. Our data suggest that hepatitis B virus vaccine coverage in Brazil should be extended to include teenagers in populations that have a low to moderate hepatitis B virus prevalence. It is likely that our results can be extrapolated to other areas of Latin America with a similar epidemiological pattern.

Antenatal screening for hepatitis B infection and syphilis in the UK.

To assess antenatal hepatitis B and syphilis screening policies in the UK. Postal questionnaire survey. One hundred and ninety-two obstetric units and 116 Public Health directorates. Antenatal screening policy and line of responsibility for ensuring vaccine uptake in hepatitis B virus exposed children. Replies were received from 140 (73%) obstetric centres and 99 (85%) Public Health directors. Forty per cent of obstetric centres now offer hepatitis B virus tests to all pregnant women, and nearly one-quarter (24.1%) of all births in the UK in 1996 occurred in centres with a universal testing policy. The prevalence of chronic hepatitis B virus ranged from 0.3 to 17.5 per 1000 deliveries. Universal antenatal screening for serological evidence of syphilis was the norm, but five obstetric centres respondents and three Public Health directors were considering its discontinuation. In the nine London centres, syphilis prevalence was 2.06 per 1000 pregnant women, compared with 0.24 per 1000 elsewhere. Responses from Public Health directors indicated the nonspecific nature of the antenatal care contract. Responsibility for hepatitis B virus vaccination of the newly born infant rests with the hospital paediatrician, with transfer of responsibility to the community usually occurring through a discharge letter. Only two areas had a monitoring system to ensure full hepatitis B virus vaccination coverage of exposed infants. If antenatal screening policies are to be equitable there is a need for a clear national policy, and systems need to be established to monitor local policy and practice.