Iman I. Salama

Occult hepatitis B virus infection among Egyptian blood donors

AIM To identify blood donors with occult hepatitis B virus (HBV) infection (OBI) to promote safe blood donation. METHODS Descriptive cross sectional study was conducted on 3167 blood donors negative for hepatitis B surface antigen (HBsAg), hepatitis C antibody (HCV Ab) and human immunodeficiency virus Ab. They were subjected to the detection of alanine aminotransferase (ALT) and aspartate transaminase (AST) and screening for anti-HBV core antibodies (total) by two different techniques; [Monoliza antibodies to hepatitis B core (Anti-HBc) Plus-Bio-Rad] and (ARC-HBc total-ABBOT). Positive samples were subjected to quantitative detection of antibodies to hepatitis B surface (anti-HBs) (ETI-AB-AUK-3, Dia Sorin-Italy). Serum anti-HBs titers > 10 IU/L was considered positive. Quantitative HBV DNA by real time polymerase chain reaction (PCR) (QIAGEN-Germany) with 3.8 IU/mL detection limit was estimated for blood units with negative serum anti-HBs and also for 32 whose anti-HBs serum titers were > 1000 IU/L. Also, 265 recipients were included, 34 of whom were followed up for 3-6 mo. Recipients were investigated for ALT and AST, HBV serological markers: HBsAg (ETI-MAK-4, Dia Sorin-Italy), anti-HBc, quantitative detection of anti-HBs and HBV-DNA. RESULTS 525/3167 (16.6%) of blood units were positive for total anti-HBc, 64% of those were anti-HBs positive. Confirmation by ARCHITECT anti-HBc assay were carried out for 498/525 anti-HBc positive samples, where 451 (90.6%) confirmed positive. Reactivity for anti-HBc was considered confirmed only if two positive results were obtained for each sample, giving an overall prevalence of 451/3167 (14.2%) for total anti-HBc. HBV DNA was quantified by real time PCR in 52/303 (17.2%) of anti-HBc positive blood donors (viral load range: 5 to 3.5 x 10(5) IU/mL) with a median of 200 IU/mL (mean: 1.8 x 10(4) ± 5.1 x 10(4) IU/mL). Anti-HBc was the only marker in 68.6% of donors. Univariate and multivariate logistic analysis for identifying risk factors associated with anti-HBc and HBV-DNA positivity among blood donors showed that age above thirty and marriage were the most significant risk factors for prediction of anti-HBc positivity with AOR 1.8 (1.4-2.4) and 1.4 (1.0-1.9) respectively. Other risk factors as gender, history of blood transfusion, diabetes mellitus, frequent injections, tattooing, previous surgery, hospitalization, Bilharziasis or positive family history of HBV or HCV infections were not found to be associated with positive anti-HBc antibodies. Among anti-HBc positive blood donors, age below thirty was the most significant risk factor for prediction of HBV-DNA positivity with AOR 3.8 (1.8-7.9). According to HBV-DNA concentration, positive samples were divided in two groups; group one with HBV-DNA ≥ 200 IU/mL (n = 27) and group two with HBV-DNA < 200 IU/mL (n = 26). No significant difference was detected between both groups as regards mean age, gender, liver enzymes or HBV markers. Serological profiles of all followed up blood recipients showed that, all were negative for the studied HBV markers. Also, HBV DNA was not detected among studied recipients, none developed post-transfusion hepatitis (PTH) and the clinical outcome was good. CONCLUSION OBI is prevalent among blood donors. Nucleic acid amplification/HBV anti core screening should be considered for high risk recipients to eliminate risk of unsafe blood donation.

High prevalence of occult hepatitis B in hepatitis C-infected Egyptian children with haematological disorders and malignancies.

Objective: This study investigates the prevalence of occult hepatitis B virus (HBV) in children and adolescents with haematological diseases with or without hepatitis C virus (HCV) infection.

Effectiveness of hepatitis B virus vaccination program in Egypt: Multicenter national project.

AIM To assess the effectiveness of hepatitis B virus (HBV) vaccination program among fully vaccinated children. METHODS A national community based cross-sectional study was carried out in 6 governorates representing Egypt. A total of 3600 children aged from 9 mo to 16 years who were fully vaccinated with HBV vaccine during infancy were recruited. Face to face interviews were carried out and sera were evaluated for hepatitis B surface antigen (HBsAg), anti-HBV core antibodies (total) and quantitative detection of hepatitis B surface antibody using enzyme linked immunoassays techniques. Samples positive to HBsAg/anti-HBV core antibodies were subjected to quantitative HBV-DNA detection by real time polymerase chain reaction with 3.8 IU/L detection limit. RESULTS Sero-protection was detected among 2059 children (57.2%) with geometric mean titers 75.4 ± 3.6 IU/L compared to 3.1 ± 2.1 IU/L among non-seroprotected children. Multivariate logistic analysis revealed that older age and female gender were the significant predicting variables for having non sero-protective level, with adjusted odds ratio 3.3, 9.1 and 14.2 among children aged 5 to < 10, 10 to < 15 and ≥ 15 years respectively compared to those < 5 years and 1.1 among girls compared to boys with P < 0.01. HBsAg was positive in 0.11% and breakthrough infection was 0.36% and 0.39% depending on positivity of anti-HBc and DNA detection respectively. The prevalence of HBV infection was significantly higher among children aged ≥ 7 years (0.59%) compared to 0.07% among younger children with odds ratio equal to 8.4 (95%CI: 1.1-64.2) and P < 0.01.The prevalence was higher among girls (0.48%) than boys (0.29%) with P > 0.05. CONCLUSION The Egyptian compulsory HBV vaccination program provides adequate protection. Occult HBV infection exists among apparently healthy vaccinated children. Adherence to infection control measures is mandatory.

Immune response to second vaccination series of hepatitis B virus among booster dose non-responders.

OBJECTIVE To evaluate the response to second vaccination series among post-booster sero-negative children who had previously received compulsory HBV vaccination. SUBJECTS AND METHODS After given a booster dose to 1070 children, 103 of them failed to generate anamnestic response (anti-HBs <10 IU/L). Only 91/103 children received additional two doses of recombinant HBV vaccine (i.e. 2(nd) vaccination series) after 1 and 6 months post-booster. Blood sample was withdrawn aseptically one month later for quantitative assessment of anti-HBs to detect development of protective immune response (≥10 IU/L). Immunological vaccination failure was assigned to children who did not develop protective immune response after 2(nd) vaccination series. RESULTS Protective immune response was detected among 84/91 children (92.3%). While 7/91 (7.7%) whose age were ≥10 years did not respond and had post-booster undetectable anti-HBs. About 80% of children with post-booster detectable anti-HBs showed significant protective immune response (anti-HBs ≥100 IU/L) and higher GMT (299.1 ± 3.6 IU/L) compared to those with undetectable 60% and 106.2 ± 12.9 IU/L respectively (P<0.05). No significant difference was detected as regards gender or residence, P>0.05. All children with history of rheumatic fever (7 children) or diabetes mellitus (1 child) developed immune response after 2(nd) vaccination series. CONCLUSION A booster dose of HB vaccine may be unable to induce sufficient immunological response in children who had undetectable anti-HBs titers. Revaccination for non-responders is an important procedure to increase HBV protection rate.

Hepatitis B long-term seroprotection and the response to a challenging dose among vaccinated children in Gharbeya Governorate

ObjectiveThe aim of the study was to assess the long-term effectiveness of hepatitis B virus (HBV) vaccine and the need for a booster dose among fully vaccinated children during infancy in Gharbeya Governorate. Patients and methodsA cross-sectional study was conducted using a multistage random sampling in one city and three villages in Gharbeya Governorate. Face-to-face interview with parents of 762 children was carried out. Blood samples were collected to assess HBV markers using enzyme-linked immunosorbent assay technique. Children having no HBV seroprotection received a challenging booster dose of HBV vaccine to assess their anamnestic response 3 weeks later. ResultsNone of the participants had an evidence of chronic or breakthrough HBV infection, and the seroprotection rate was 57%. On multivariate analysis, the risk of nonseroprotection was found to be significantly higher among children aged from 5 to less than 10, 10 to less than 15, and 15 years and above compared with those aged less than 5 years [adjusted odds ratio (AOR)=3.4, 10.2, and 18.5, respectively], among girls compared to boys (AOR=1.5), and among those living in Kotour and Elsanta villages compared with Tanta city (AOR=1.8). Of the 265 children with nonseroprotective levels, 91.7% developed anamnestic response after a challenging dose. Anamnestic response rate was 100% at age 1 year and decreased to 89% at age 16 years (P>0.05). ConclusionLong-term immunity exists among children who had complete series of hepatitis B vaccination in infancy even in case of reduced or absent anti-hepatitis B over time. The developed high anamnestic response rate signifies the presence of immune memory and indicates no need for a booster dose.

Early and long term anamnestic response to HBV booster dose among fully vaccinated Egyptian children during infancy

OBJECTIVE To evaluate early and long term anamnestic response to a booster dose of HBV vaccine among non-seroprotected children. SUBJECTS AND METHOD A national community based project was carried out on 3600 children aged 9 months to 16 years, fully vaccinated during infancy. They were recruited from 6 governorates representing Egypt. It revealed that 1535 children (42.8%) had non sero-protective anti-HBs (<10 IU/L) and were HBsAg or anti-HBc negative. A challenging dose of 10 μg of mono-valent Euvax HBV vaccine was given to 1121/1535 children. Quantitative assessment of anti-HBs was performed to detect early (2-4 weeks) and long term (one year) anamnestic responses. RESULTS Early anamnestic response developed among 967/1070 children (90.3%).Children having detectable anti-HBs (1-9 IU/L) significantly developed early anamnestic response (90%) compared to 85% with undetectable anti-HBs (<1 IU/L), P < 0.001. Multiple logistic analysis revealed that undetectable anti-HBs, living in rural residence and children aged 15-16 years were the most significant predicting risk factors for the absence of early anamnestic response (<10 IU/L), with AOR 2.7, 2.7 & 4.7 respectively. After one year, long term anamnestic response was absent among 15% of children who previously showed early response. Poor early anamnestic response and undetectable pre-booster anti-HBs were the significant predicting risk factors for absent long term anamnestic response, with AOR 18.7 & 2.7 respectively. CONCLUSION Immunological memory for HBV vaccine outlasts the presence of anti- HBs and HBV vaccination program provides effective long term protection even in children showing waning or undetectable concentrations of anti-HBs. This signifies no need for a booster dose especially to healthy children.

Hepatitis B seroprotection and the response to a challenging dose among vaccinated children in Red Sea Governorate.

AIM: To assess the long-term effectiveness of hepatitis B virus vaccine and the need for a booster dose among children who received three doses of vaccine during infancy in Red Sea Governorate. METHODS: A cross-sectional study was performed. Interviews with children (9 months to 16 years) and parents were done. Blood samples to assess Hepatitis B markers were tested. Children showing no seroprotection received a booster dose to assess their anamnestic response after four weeks and one year later. RESULTS: None of the participants had evidence of chronic Hepatitis B. The seroprotection rate was 23.3% and it significantly decreased with age. Multivariate logistic analysis revealed that older age was the significant predicting variable for having no seroprotective level, while baseline anti-HBs level < 3.3 IU/L was the predicting variable for not developing early anamnestic response or loss of late anamnestic response. CONCLUSION: Long-term immunity persists among children who received complete series of hepatitis B vaccination during infancy even in absence or reduction of anti-HBs over time. Therefore, a booster dose is not necessary to maintain immunity till the age of sixteen.

Hepatitis B infection, seroprotection, and anamnestic response among children vaccinated during infancy in Beni-Suef, Egypt

ObjectivesThe aims of this study were to evaluate the long-term seroprotection after hepatitis B virus (HBV) vaccination and to assess the need for a booster dose among children vaccinated during infancy. Patients and methodsA cross-sectional study was carried out in two areas in the Beni-Suef governorate (El-Wasta city and Blevia village) using a multistage random sampling. Face-to-face interviews of 362 children and their parents were carried out. Blood samples were collected to assess hepatitis B surface antigen (HBsAg), total hepatitis B core antibody (anti-HBc), and antibodies to hepatitis B surface antigen (anti-HBs) using ELISA. Positive samples for HBsAg/anti-HBc were subjected to quantitative HBV-DNA detection by a real-time PCR. Children with HBV non-sero-protection received a booster dose of the HBV vaccine to assess their anamnestic response 4 weeks later. ResultsFour (1.1%) of the participants had evidence of breakthrough HBV infection and the seroprotection rate was 57%. On multivariate analysis, the risk of non-sero-protection was significantly higher among children aged 5to less than 10 years, 10 to less than 15, and at least 15 years compared with younger children [adjusted odds ratio (AOR)=5.2, 18.6, and 19.7, respectively] and those living in rural compared with urban areas (AOR=2.1). Out of 117 children with non-sero-protective levels, 86.3% developed an anamnestic response after a booster dose. ConclusionLong-term HBV immunity exists among children vaccinated during infancy even in case of reduced or absent anti-HBs over time. The high anamnestic response rate developed signifies the presence of immune memory and indicates that there is no need for a booster dose.