Anti-HBs levels among children and adolescents with complete immunization schedule against hepatitis B virus. A cross-sectional study in Blumenau, State of Santa Catarina, Brazil, 2007-2008

Protective immunity against hepatitis B virus infection in a group of vaccinated Sri Lankan military service men following a complete course of vaccination

Vaccination is the appropriate measure to protect military personnel against the hepatitis B virus (HBV) infection. Testing the military personnel for anti-HBs levels after vaccination is vital in re-vaccinating those that have not developed protective immunity. The aim of the current study was to determine the immunity in a group of vaccinated Sri Lankan military personnel (n = 150; age = 26-44 years) following a complete course of hepatitis B virus surface antigen (HBsAg) vaccination by assessing the antibodies against HBsAg (anti-HBs) levels. Three months after the last dose of the vaccination, blood samples were collected from the study population and tested for anti-HBs levels using a commercially available ELISA. Of the 150 military service men tested, 139 (92.67%) had anti-HBs levels higher than 10 mIU/mL, WHO approved levels for protective immunity against HBV infection. Of the 139 that had sufficient anti-HBs levels, 24% (36/150) had anti-HBs levels between 10 and 100 mIU/mL and 68.67% (103/150) had anti-HBs levels > 100 mIU/mL. Overall, 7.33% (11/150) participants had anti-HBs levels < 10 mIU/mL. Sero-conversion to > 10 mIU/mL anti-HBs was more than 90% in those that were less than 40 years of age and it was less than 90% in those that were more than 40 years of age.

Anti-Hepatitis B Antibody Levels In Immunized Medical Students: Are They At Risk?

INTRODUCTION

Medical students have an occupational risk for hepatitis B (HB). This study sought to determine anti-HBs and anti-HBc IgG levels in vaccinated students, check their seroconversion, and correlate this with vaccination.

METHODS

One hundred and forty-three students' blood samples and their vaccination schedules were analyzed.

RESULTS

65.7% were positive for anti-HBs; however, anti-HBs was absent in 34.3%. Only two samples were positive for anti-HBc IgG.

CONCLUSIONS

More than 30% of students did not have minimum protective levels. Comparing HBV vaccination and anti-HBs reactivity, the majority of reactive individuals received their last dose within the past 16 years.

Knowledge of and risky behaviours towards hepatitis B virus infection among Egyptian school children

BACKGROUND AND STUDY AIMS

Success in the prevention of hepatitis B virus (HBV) depends to a large extent on the adolescents' HBV knowledge and their risky behaviours. This study aims to assess the knowledge of and the risky behaviours towards HBV among school students and to determine the significant predictors affecting their knowledge.

PATIENTS AND METHODS

A cross-sectional study was approved in four Egyptian governorates (Dakahleya, Gharbeya, Cairo, and Beni-Suef) on 574 students aged 11-17years. A questionnaire was filled through a face-to-face interview to collect data about the socio-demographic character, HBV knowledge, and risky behaviours among children who were chosen for this study.

RESULTS

While 75% of students had poor levels of HBV knowledge, 1.7% had good levels of knowledge. As regards gender, more than 60% of students shared scissors and went to dental clinic with no significant difference. While boys reported a significant history of hospitalisation (50.2%) and wound stitches (36%), girls reported a lesser degree of the same (40.2% and 22.6, respectively), p<0.01. During logistic regression analysis, the most important predictors of poor HBV knowledge were age <15years and living in Cairo governorate, with adjusted odds ratio (AOR) 1.5 and 5.0, respectively.

CONCLUSION

The majority of students chosen for the study had low levels of knowledge and high risky behaviours towards viral hepatitis. In order to minimise the risky behaviours among adolescents, health education programmes should be conducted concerning the mode of transmission and prevention of viral hepatitis.

Immunogenicity of Recombinant Hepatitis B Vaccine Among Routinely Vaccinated Healthy and Chronically Ill Children in Assiut, Upper Egypt

BACKGROUND

Egypt is considered a region of the intermediate prevalence of hepatitis B virus (HBV) infection (4.5%). Seroprotection is assured when hepatitis B surface antibody (HBsAb) levels are ≥ 10 mIU/mL. Our study aimed to evaluate and compare the long-term immunogenicity and efficacy of the recombinant hepatitis B (HB) vaccine.

METHODS

A cross-sectional study was done for children aged from 9 months to 15 years, receiving health care at Assiut University Children's Hospital, Assiut, Egypt in 3 months. HBsAb was quantitatively determined by enzyme-linked immune sorbent assay (ELISA).

RESULTS

Seroprotection in infants less than 1 year was 89.7% with 55.2% having titer > 100 mIU/mL and this percent dropped to 64.4% after the first year of age with only 29% having titer > 100 mIU/mL. The overall protection percentage was 32.5% (> 100 mIU/mL), 34.7% of children showed levels between 10 and 100 mIU/mL, while 32.8% were less than 10 mIU/mL. Patients with diabetes mellitus were found to have the lowest seroprotective levels (83.3% were not protected). Non-protective levels were also detected in patients with malnutrition (55.6%), congenital heart diseases (43.2%) and chronic liver diseases (57.1%).

CONCLUSION

Our study shows failure to achieve satisfactory seroprotective levels for hepatitis B vaccine in both healthy and diseased children who adopted vaccination schedule in Upper Egypt. Booster dose in the second year of life is recommended for all children, particularly for those with diabetes millets, congenital heart disease and malnutrition.

Vaccination coverage and immunity against hepatitis B among HIV-infected patients in South Brazil

Evidence-based strategies to improve the hepatitis B virus (HBV) vaccination coverage rates might help to reduce the burden caused by co-infection with HBV and human immunodeficiency virus (HIV). In this study, the aim was to evaluate the vaccination coverage and immunity against HBV among HIV-infected individuals in South Brazil, and identify factors that are associated with compliance patterns and antibody reactivity. Three hundred HIV-infected men and women were included in this survey. The patients answered a standardized questionnaire, and vaccination cards were checked in order to assess hepatitis B vaccine status. A blood sample was collected for quantitative determination of antibody to hepatitis B virus surface antigen (anti-HBs). Participants were also evaluated for their CD4 cell count and HIV viral load. The overall vaccination coverage of HBV vaccination found in this study (57.4%) was lower than that was previously reported in South Brazil. Anti-HBs levels >10 IU/L were observed in 47.0% of the studied population. A significant inequality in the coverage rates and antibody reactivity was found in favor of patients with better economic status. In conclusion, the results indicate the need for improvement in the HBV vaccination coverage among HIV carriers, in particular focusing on low-income individuals.

Long-term efficacy of the hepatitis B vaccine in a high-risk group

Chronic infection with hepatitis B virus (HBV) is a global health problem. In an attempt to control infection, worldwide HBV vaccination programs have been established. Saudi Arabia, an endemic area for HBV infection, established an HBV immunization program in 1989. This cross-sectional study evaluates the long-term protection of HBV vaccination 14-24 years after primary immunization in a high-risk group (clinical year medical students) at King Abdulaziz University Hospital in Jeddah, Saudi Arabia. All participants had complete HBV immunization at birth or in early childhood. Hepatitis B surface antibody (anti-HBs) levels were obtained. An anti-HBs titer of <10 mIU/ml indicated no protection, while a titer of >10 mIU/ml was considered to represent protective immune status. A total of 238 students were included; they were predominantly females (n = 182, 76.5%). Mean age was 22.2 ± 1.1 years. Duration since primary vaccination was 19.8 ± 2.3 years. Female students were more likely to maintain long-term protection compared to males (62.1% and 58.8%, respectively). Anti-HBs levels were significantly low in many students after primary immunization. Testing medical students for anti-HBs levels may be warranted as they represent a high-risk population. The higher rate of vaccine failure in males than females requires further investigation as it may explain the higher prevalence of HBV in the male population.

Serum levels of anti-hepatitis B surface antibody among vaccinated population aged 1 to 18 years in ahvaz city southwest of iran

BACKGROUND

The duration of protection following primary series vaccination against hepatitis B is unknown in children and adolescents. It has been shown that the level of anti-hepatitis B surface antigen antibodies (anti HBs Ab) declines over years after vaccination.

OBJECTIVES

The aim of this study was to estimate the long-term immunity against hepatitis B virus infection among children and adolescents who had received a complete hepatitis B vaccination series during infancy.

PATIENTS AND METHODS

In a cross-sectional study, the - anti-HBsAb levels of 840 vaccinated children and adolescents were determined by enzyme-linked immunosorbent assay.

RESULTS

Hepatitis B seroprotection rates (anti HBsAb ≥ 10 IU/L) among vaccinated children and adolescents aged 1 and 18 years were 90% and 48.9%, respectively. The declining trend of geometric mean titer of anti-HBsAb levels was observed as changed from 272.3 IU/L to 94.1 IU/L in 1 and 18-year-old population, respectively. A significant negative correlation was found between age and anti-HBsAb levels (r = - 0.220, P = 0.0001).

CONCLUSIONS

The results showed a declining trend in anti-HBsAb titers over the time after vaccination against hepatitis B virus in our region. Further studies are warranted to establish the need for a booster dose in cases that are at risk of hepatitis B virus infection.

Hepatitis B: knowledge, vaccine situation and seroconversion of dentistry students of a public university

BACKGROUND

Viral hepatitis B (VHB) is an occupational risk for dentists. It is necessary that dental students start clinical practice immunized with the vaccine, response monitored and informed about the means of transmission of the disease. Rarely, there are studies, which evaluate concomitantly knowledge of these academics and their vaccine situation.

OBJECTIVES

To evaluate the knowledge about Hepatitis B, the vaccine situation and the immunization status of dental students and to investigate the probable correlation between the status of immunization, vaccination membership and adherence to the test of seroconversion and associated factors.

PATIENTS AND METHODS

189 students from the dentistry course at the Federal University of Piaui (UFPI) who attended from the 3rd to 9th period were invited to participate in the research. Their knowledge about HBV, attitude regarding protection and their vaccine situation were assessed through a self-administered form. Antibodies against surface antigens of Hepatitis B virus (Anti-HBs) and against the antigens of the virus nucleous of Hepatitis B (Anti-HBc total) were measured qualitatively using the enzyme-linked immunosorbent assay (ELISA).

RESULTS

Of the 179 students surveyed, 58.1% knew about the degree of virulence of the Hepatitis B virus (HBV). As to the means of transmission, 98.3% considered blood transmission, 82.6% plates and cutlery, 15.6% cough and 12.3% vertical transmission. Most students (87.4%) knew that they should take 3 doses of the vaccine and 62.2% completed the immunization schedule. A minority of students (48.6%) knew the about the Anti-HBs test and 5.6% took the test. Among the students who reported having taken three doses of the vaccine, 12.5% were not seroconverted. There was no significant correlation between the variables.

CONCLUSIONS

Dental academics were unsure about the means of infection and prevention against HBV. Many of them had not completed the immunization scheme and did not have the test of seroconversion. The serological analysis revealed unprotection, even after students completed the vaccination schedule.