Hepatitis B vaccination coverage among adults aged ≥ 18 years traveling to a country of high or intermediate endemicity, United States, 2015

Prevalence of hepatitis B virus infection and its associated factors among students in N'Djamena, Chad

INTRODUCTION

Infection by hepatitis B virus (HBV) is a major issue in public health. The prevalence of HBV in Chad is 12.4%, all age groups considered. Here, we aimed to determine the prevalence of HBV and its associated factors among university students in N'Djamena, the country's capital.

METHODS

A cross-sectional survey of students at either the University of N'djamena or Emi Koussi University was conducted from 3 to 23 July 2021. All participating students provided signed, informed consent and were included in the study consecutively. Blood samples were collected, and serum tested for hepatitis B surface antigen (HBsAg) using the Determine HBsAg rapid test kit, with confirmation of positive tests on an Abbott Architect i1000SR analyzer. Descriptive analysis and logistic regression were used to determine associations between the outcome variable and independent/covariate variables.

RESULTS

A total of 457 students with a median age of 24 years were included across different faculties. The prevalence of HBV infection was 14.87% (68/457). Most students (75%) were aged 25 years or less. Unprotected sex was reported by 64.9% of the students and multiple sexual partners by 53.6%. Furthermore, 45.7% of them reported having no knowledge of hepatitis B. Having an HBsAg-positive mother (AOR: 2.11), having a history of transcutaneous medical procedures (AOR: 2.97) and living with a family (AOR: 4.63) were significantly associated with HBV status. Age ≥26 years appeared as a protective factor (AOR = 0.41).

CONCLUSION

Our study detected a high, 14.87% prevalence of HBV infection among students in N'djamena, Chad, and shed light on its associated factors. HBV prevention strategies should include raising awareness among students, making full hepatitis vaccination mandatory before children begin school, promoting mass screening to identify and treat chronic HBV carriers and reduce transmission, and reducing the cost of vaccination.

Travel vaccines-priorities determined by incidence and impact

BACKGROUND

Infectious disease epidemiology is continuously shifting. While travel has been disrupted by the COVID-19 pandemic and travel-related epidemiological research experienced a pause, further shifts in vaccine-preventable diseases (VPDs) relevant for travellers have occurred.

METHODS

We conducted a literature search on the epidemiology of travel-related VPD and synthesized data for each disease with a focus on symptomatic cases and on the impact of the respective infection among travellers, considering the hospitalization rate, disease sequela and case fatality rate. We present new data and revised best estimates on the burden of VPD relevant for decisions on priorities in travel vaccines.

RESULTS

COVID-19 has emerged to be a top travel-related risk and influenza remains high in the ranking with an estimated incidence at 1% per month of travel. Dengue is another commonly encountered infection among international travellers with estimated monthly incidence of 0.5-0.8% among non-immune exposed travellers; the hospitalized proportion was 10 and 22%, respectively, according to two recent publications. With recent yellow fever outbreaks particularly in Brazil, its estimated monthly incidence has risen to >0.1%. Meanwhile, improvements in hygiene and sanitation have led to some decrease in foodborne illnesses; however, hepatitis A monthly incidence remains substantial in most developing regions (0.001-0.01%) and typhoid remains particularly high in South Asia (>0.01%). Mpox, a newly emerged disease that demonstrated worldwide spread through mass gathering and travel, cannot be quantified regarding its travel-related risk.

CONCLUSION

The data summarized may provide a tool for travel health professionals to prioritize preventive strategies for their clients against VPD. Updated assessments on incidence and impact are ever more important since new vaccines with travel indications (e.g. dengue) have been licensed or are undergoing regulatory review.

Adult Hepatitis B Virus Vaccination Coverage in China from 2011 to 2021: A Systematic Review

Background: The most effective way to prevent hepatitis B virus (HBV) infection is vaccination. Synthesized data on vaccination coverage in adults against hepatitis B in China are scarce. We aimed to estimate the hepatitis B vaccination rate in adults in China. Methods: We searched PubMed, EMBASE, Cochrane Library, China National Knowledge Infrastructure, WanFang, and Sinomed databases for observational studies published between 1 January 2011 and 1 October 2021. Data were extracted using a standardized form to estimate the pooled vaccination coverage rate and 95% confidence intervals (CI) based on inclusion and exclusion criteria. Subgroup analysis was employed to explore heterogeneity. This study is registered in PROSPERO, CRD42021293175. Results: We identified 5128 records, of which 21 articles that included 34,6571 adults. The pooled coverage rate and 95% confidence intervals were 26.27% and 22.73–29.82%, respectively. The pooled coverage rates were 22.06% (95% CI: 15.35–28.78%), 33.81% (95% CI: 28.77–38.85%) and 23.50% (95% CI: 17.37–29.64%) in eastern China, central China and western China, respectively. Furthermore, males had a pooled hepatitis B vaccination coverage rate of 23.47% (95% CI: 15.61–31.33%), whereas, in females, the coverage rate was 26.60% (95% CI: 18.73–34.47%). The pooled hepatitis B vaccination coverage rate in the age group younger than 40 years was 36.93% (95% CI: 28.35–45.50%), while in the ≥40-year-old group, the pooled hepatitis B vaccination coverage rate was 17.09% (95% CI: 10.18–24.00%). The pooled hepatitis B vaccination coverage rate in urban areas (40.29%, 95% CI: 20.91–59.67%) was higher than in rural areas (16.54%, 95% CI: 7.80–25.29%). The average weighted, pooled hepatitis B vaccination coverage rate was 26.53% (20.25–32.81%) in 2011–2015 and 26.12% (22.04–30.20%) in 2016–2021. Conclusions: This systematic review provides the hepatitis B vaccination coverage rate of adults in China (26.27%). The low prevalence of vaccine-mediated immunity among adults in China underscores the urgent need for targeted immunization strategies for vulnerable Chinese adults to ensure progress toward the target of eliminating hepatitis B by 2030.

Seroprevalence of hepatitis B antibodies among international and domestic university students

Chronic hepatitis B prevalence is low in most Australian populations, with universal infant HBV vaccination introduced in 2000. Migrants from high prevalence countries are at risk of acquisition before arrival and non-immune adults are potentially at risk through skin penetrating procedures and sexual contact, particularly during international travel. The risk profile of young adult students, many from high prevalence countries, is inadequately understood. A cross-sectional online survey conducted among university students collected data on demographic, vaccination and travel characteristics and blood samples were tested for hepatitis B surface antibody (HBsAb) and hepatitis B core antibody (HBcAb). Analyses identified factors associated with HBsAb seroprevalence and self-reported vaccination. The serosurvey was completed by 804 students born between 1988 and 1993, with 613/804 (76.2%, 95% CI 73.2-79.1) self-reporting prior HBV vaccination. Overall, 526/804 (65.4%, 95% CI 62.0%-68.6%) students were seropositive to HBsAb, including 438/613 (71.5%, 95% CI 67.8-74.9) students self-reporting a prior HBV vaccine and 88/191 (46.1%, 95% CI 39.2-53.2) students self-reporting no prior HBV vaccine. Overall, 8/804 (1.0%, 95% CI 0.5%-2.0%) students were HBcAb positive, of whom 1/804 (0.1%, 95% CI 0.02%-0.7%) was currently infectious. The prevalence of chronic HBV infection was low. However, more than one in four students were susceptible to HBV and over-estimated their immunity. Future vaccination efforts should focus on domestic students born before the introduction of the infant program and all international students. Screening and vaccination of students, including through campus-based health services, are an opportunity to catch-up young adults prior to undertaking at-risk activities, including international travel.

Determinants of Hepatitis B Virus (HBV) Infection Among University Students in Central Bangladesh

This study aimed to determine the seroprevalence and determinants of hepatitis B virus (HBV) infection among university students in Bangladesh. This cross-sectional study was conducted among 614 students from five universities in central Bangladesh. Data were collected on demographic information, immunization history, medical and blood transfusion history through the face-to-face interview. Blood samples were collected and screened for anti-HBsAg using ELISA, HBsAg Rapid Test-cassette, and immune chromatographic test. The overall seroprevalence of HBV infection was 5.0%, and vaccination coverage was 19.2% among the participants. Students having a history of surgery (OR 11.004, 95% CI 3.211-37.707), blood transfusion (OR 5.651, 95% CI 0.965-33.068), being married (OR 4.776, 95% CI 1.508-15.127), and not being vaccinated (OR 9.825, 95% CI 1.130-85.367) were at higher risk of being infected by HBV. This study showed the endemicity of HBV infection among the Bangladeshi population. Marriage, surgical or blood transfusion history, not being vaccinated were the determinants of HBV infection within the study population. Public health initiatives for preventing HBV infection at the university levels should be envisaged.

Hepatitis B virus infection and associated risk factors among medical students in eastern Ethiopia

BACKGROUND

Hepatitis B virus (HBV) is a highly contagious pathogen that has become a severe public health problem and a major cause of morbidity and mortality, particularly in developing countries. Medical students are at high occupational risk during their training. However, no facility-based studies were found among medical students in eastern Ethiopia. Thus, this study aimed to investigate the seroprevalence of Hepatitis B Virus and associated factors among medical students in eastern Ethiopia.

METHODS

A facility-based cross-sectional study was conducted among 407 randomly selected medical students from March to June 2018. A pretested and structured questionnaire was used to collect data on socio-demographic characteristics and other risk factors. A 5ml blood was collected, and the serum was analyzed for Hepatitis B surface antigen (HBsAg) using the Instant Hepatitis B surface antigen kit. Data were entered using Epidata version 3.1 and analyzed using SPSS statistical packages version 22. Outcome and explanatory variables were described using descriptive summary measures. Binary and multivariable logistic regression was conducted at 95% CI and an association at P-value < 0.05 was declared statistically significant.

RESULTS

The seroprevalence of hepatitis B virus surface antigen was 11.5% (95%CI = 8.6, 14.7). Poor knowledge of universal precaution guideline (AOR = 2.58; 95% CI = [1.35-4.93]), history of needle stick injury (AOR = 2.11; 95% CI = [1.07-4.18]) and never been vaccinated for HBV (AOR = 2.34; 95% CI = [1.17-4.69]) were found statistically significantly associated with HBsAg positivity after multivariate analysis.

CONCLUSION

Hepatitis B virus infection rate is high among health care trainees in eastern Ethiopia. Improvement at health care practice centers safety through training on universal precaution guidelines, and scaling up HBV vaccination is mandatory.

Characteristics associated with hepatitis B vaccination initiation and completion among adults traveling to a country of high or intermediate endemicity

BACKGROUND

The hepatitis B (HepB) vaccine is recommended for adults traveling to a country of high or intermediate endemicity.

METHODS

Data from the 2016 and 2017 National Health Interview Surveys were pooled.

RESULTS

The weighted prevalence of HepB vaccination initiation (≥1 dose) was 37.67% in 2016 (weighted number: 30,581,813/81,192,803) and 40.20% in 2017 (weighted number: 34,509,993/85,849,427). The weighted prevalence of HepB vaccination completion (≥3 doses) was 29.97% in 2016 (weighted number: 24,331,218/81,192,803) and 31.78% in 2017 (weighted number: 27,282,536/ 85,849,427). Characteristics independently associated with HepB vaccination initiation (in descending order by odds ratio) included age, receipt of influenza vaccine, education, ever having lived with someone with hepatitis, class of worker, number of physician visits in the past 12 months, ratio of family income to the poverty threshold, region, sexual orientation, gender, heath insurance, computer use, physical activity, and Hispanic ethnicity. Similar results were found in the analysis for HepB vaccination completion, except that subjects born in the United States showed a higher likelihood of HepB vaccination completion.

CONCLUSIONS

HepB vaccination initiation and completion were associated with a number of characteristics that can be utilized to develop strategies to increase HepB vaccination coverage among adults traveling to a country of high or intermediate endemicity.

Adherence to hepatitis A and hepatitis B multi-dose vaccination schedules among adults in the United Kingdom: a retrospective cohort study

BACKGROUND

Timely and complete vaccination with multi-dose schedules is of public health importance, because an incomplete vaccination series may yield suboptimal disease protection. However, data on adherence of adults to multi-dose vaccines are limited. We sought to estimate adherence to multi-dose hepatitis vaccination schedules among adults in the United Kingdom (UK).

METHODS

This retrospective cohort study was conducted using anonymized electronic health record (EHR) data from the Clinical Practice Research Datalink (CPRD). Individuals aged 19 years and older at their first identified dose of hepatitis vaccine (2009-2016) were included if they had continuous EHR data for 12 months before the first identified hepatitis A dose or for 6 months before the first identified hepatitis B or combination hepatitis A/B dose. We estimated dose and series completion for each vaccine and adherence to recommended vaccination schedules, as well as adherence within additional prespecified time periods after the first vaccine dose, with sensitivity analyses restricted to adults who had available data for up to 24 months after the first dose. Median time to series completion was estimated using Kaplan-Meier methods.

RESULTS

Mean (SD) age at initiation was 42 (16) years for hepatitis A (n = 374,881), 40 (16) years for hepatitis B (n = 71,634), and 38 (15) years for hepatitis A/B (n = 10,335). Women comprised 52 to 55% of each vaccine cohort. Overall, 42,294 adults (11%) completed the two-dose hepatitis A vaccine series within the recommended 12 months; and 15,564 (22%) and 1076 (10%) completed the three-dose hepatitis B and hepatitis A/B series, respectively, within the recommended 6 months. These percentages rose to only 23, 35, and 33%, respectively, when the follow-up periods were extended to 36 months for hepatitis A and to 30 months for hepatitis B and A/B vaccines. Median times to series completion within recommended schedules were not reached in any cohort. Sensitivity analyses supported the primary findings for the full cohorts.

CONCLUSIONS

Adherence and series completion rates for hepatitis A and B vaccines in the UK are low. Identifying, understanding, and addressing barriers to series completion for multi-dose vaccines for adults in real-world settings are needed.