Hepatitis B Virus Surface Antigen Test Research Articles

Systematic Optimization of Universal Real-Time Hypersensitive Fast Detection Method for HBsAg in Serum Based on SERS.

Hepatitis B virus (HBV) is a major cause of liver cirrhosis and hepatocellular carcinoma, with HBV surface antigen (HBsAg) being a crucial marker in the clinical detection of HBV. Due to the significant harm and ease of transmission associated with HBV, HBsAg testing has become an essential part of preoperative assessments, particularly for emergency surgeries where healthcare professionals face exposure risks. Therefore, a timely and accurate detection method for HBsAg is urgently needed. In this study, a surface-enhanced Raman scattering (SERS) sensor with a sandwich structure was developed for HBsAg detection. Leveraging the ultrasensitive and rapid detection capabilities of SERS, this sensor enables quick detection results, significantly reducing waiting times. By systematically optimizing critical factors in the detection process, such as the composition and concentration of the incubation solution as well as the modification conditions and amount of probe particles, the sensitivity of the SERS immune assay system was improved. Ultimately, the sensor achieved a sensitivity of 0.00576 IU/mL within 12 min, surpassing the clinical requirement of 0.05 IU/mL by an order of magnitude. In clinical serum assay validation, the issue of false positives was effectively addressed by adding a blocker. The final sensor demonstrated 100% specificity and sensitivity at the threshold of 0.05 IU/mL. Therefore, this study not only designed an ultrasensitive SERS sensor for detecting HBsAg in actual clinical serum samples but also provided theoretical support for similar systems, filling the knowledge gap in existing literature.

Hepatitis B Virus Prevalence and Transmission in the Households of Pregnant Women in Kinshasa, Democratic Republic of Congo.

The World Health Organization Africa region has high regional hepatitis B virus (HBV) prevalence, and evidence suggests more frequent horizontal HBV transmission than other regions. Context-specific epidemiological studies are needed to inform additional HBV prevention measures. In the cross-sectional Horizontal and Vertical Transmission of Hepatitis B (HOVER-HBV) study, we introduced HBV surface antigen (HBsAg) screening alongside existing HIV screening as part of routine antenatal care in high-volume maternity clinics in Kinshasa, Democratic Republic of Congo. We recruited households of pregnant women ("index mothers") who were HBsAg-positive and HBsAg-negative, defining households as index-positive and index-negative, respectively. Household members underwent HBsAg testing and an epidemiological survey. We evaluated HBsAg prevalence and potential transmission correlates. We enrolled 1006 participants from 200 households (100 index-positive, 100 index-negative) across Kinshasa. HBsAg-positivity prevalence was more than twice as high in index-positive households (5.0% [95% confidence interval {CI}, 2.8%-7.1%]) as in index-negative households (1.9% [95% CI, .6%-3.2%]). HBsAg-positivity prevalence was 3.3 (95% CI, .9-11.8) times as high among direct offspring in index-positive versus index-negative households. Factors associated with HBsAg positivity included older age, marriage, and having multiple recent partners or any new sexual partners among index mothers; and older age, lower household wealth, sharing nail clippers, and using street salons among offspring in index-positive households. Vertical and horizontal HBV transmission within households is ongoing in Kinshasa. Factors associated with infection reveal opportunities for HBV prevention efforts, including perinatal prevention, protection during sexual contact, and sanitation of shared personal items.

Atypical Hepatitis B Virus Serology Profile-Hepatitis B Surface Antigen-Positive/Hepatitis B Core Antibody-Negative-In Hepatitis B Virus/HIV Coinfected Individuals in Botswana.

(1) Background: Hepatitis B core antibodies (anti-HBc) are a marker of hepatitis B virus (HBV) exposure; hence, a normal HBV serology profile is characterized by HBV surface antigen (HBsAg) and anti-HBc positivity. However, atypical HBV serologies occur, and we aimed to determine the prevalence of an atypical profile (HBsAg+/anti-HBc-) in a cohort of people with HIV-1 (PWH) in Botswana. (2) Methods: Plasma samples from an HIV-1 cohort in Botswana (2013-2018) were used. The samples were screened for HBsAg and anti-HBc. Next-generation sequencing was performed using the GridION platform. The Wilcoxon rank-sum test and Chi-squared tests were used for the comparison of continuous and categorical variables, respectively. (3) Results: HBsAg+/anti-HBc- prevalence was 13.7% (95% CI 10.1-18.4) (36/263). HBsAg+/anti-HBc- participants were significantly younger (p < 0.001), female (p = 0.02) and ART-naïve (p = 0.04) and had a detectable HIV viral load (p = 0.02). There was no statistically significant difference in the number of mutations observed in participants with HBsAg+/anti-HBc- vs. those with HBsAg+/anti-HBc+ serology. (4) Conclusions: We report a high HBsAg+/anti-HBc- atypical serology profile prevalence among PWH in Botswana. We caution against HBV-testing algorithms that consider only anti-HBc+ samples for HBsAg testing, as they are likely to underestimate HBV prevalence. Studies to elucidate the mechanisms and implications of this profile are warranted.

Needle Sticks Injuries (NSIs) and Hepatitis B Vaccination status among Health Care Workers (HCWs) at Asia’s Largest Trauma Care Centre in Bengaluru

Background: Needle stick injuries (NSIs) are the most common workplace-related health hazards responsible for the transmission of blood-borne pathogens among the HCWs where safety measures have not already been established. Injuries mostly occur during needle recapping, operative procedures, blood sample collection, intravenous line administration and poor waste disposal practices. Following NSIs, more than 20 blood-borne pathogens can be transmitted through body fluids. However, the most common diseases that can be potentially transmitted through body fluids are HIV, HBV, and HCV. Moreover, among the three important pathogens transmitted through NSIs, only HBV has an effective vaccine. The HBV vaccination coverage among HCWs has also been generally less, putting them at greater risk for HBV infections. This study aims to analyze the swing of voluntary reporting of NSIs among HCWs and also the HBV vaccination status among those HCWs reporting NSIs in our tertiary health-care center. Materials and Methods: A retrospective study was conducted between January 2018 and March 2020 at Asia’s Largest Trauma Care Centre in Bangalore. A standard proforma was filled by all HCWs reporting NSIs and a record of the same was maintained. Testing for HIV, hepatitis B virus surface antigen (HBsAg) and HCV was provided to the HCWs and also to the sources. HIV testing, HBsAg testing, and HCV testing were done by using rapid standard kits. All the tests were performed and interpreted according to the manufacturer's instructions. The testing for HIV 1 and 2 was done according to the National AIDS Control Organization Guidelines. The HCWs were tracked up to 6 weeks, 3 months, and 6 months for HIV and at 3 months and 6 months for HBV and HCV, consecutively after guidance, counseling and appropriate interventions. Results: A total of 34 incidents of NSIs were reported between January 2018 and March 2020 in that 11 were reported in 2018, 17 and 06 in 2019 and 2020 respectively. Majority of the HCWs 50 % had complete course of HBV vaccination, 41.17% had incomplete (1 or 2 doses) and 8.82% had not taken any course of HBV vaccination. Conclusion: The study disclosed that the collective prevalence of NSI among HCWs was high. The inadequate training of HCWs among the health care facilities might make HCWs more susceptible to injury. Therefore, the current study recommends the following measures to reduce NSIs - adequate training, simulation training to mimic everyday situations of junior staff, compulsory HBV vaccination for all the HCWs, System in place for reporting, adequate first aid facility and provision of safe working environment.

The association between hepatitis B virus infection and nonliver malignancies in persons living with HIV: results from the EuroSIDA study.

The aim of this study was to assess the impact of hepatitis B virus (HBV) infection on non-liver malignancies in people living with HIV (PLWH). All persons aged ≥18 years with known hepatitis B virus (HBV) surface antigen (HBsAg) status after the latest of 1January 2001 and enrolment in the EuroSIDA cohort (baseline) were included in the study; persons were categorized as HBV positive or negative using the latest HBsAg test and followed to their first diagnosis of nonliver malignancy or their last visit. Of 17485 PLWH included in the study, 1269 (7.2%) were HBV positive at baseline. During 151766 person-years of follow-up (PYFU), there were 1298 nonliver malignancies, 1199 in those currently HBV negative [incidence rate (IR)8.42/1000 PYFU; 95% confidence interval (CI) 7.94-8.90/1000 PYFU] and 99 in those HBV positive (IR10.54/1000 PYFU; 95% CI8.47-12.62/1000 PYFU). After adjustment for baseline confounders, there was a significantly increased incidence of nonliver malignancies in HBV-positive versus HBV-negative individuals [adjusted incidence rate ratio (aIRR)1.23; 95% CI 1.00-1.51]. Compared to HBV-negative individuals, HBsAg-positive/HBV-DNA-positive individuals had significantly increased incidences of nonliver malignancies (aIRR 1.37; 95% CI 1.00-1.89) and NHL (aIRR 2.57; 95% CI 1.16-5.68). There was no significant association between HBV and lung or anal cancer. We found increased rates of nonliver malignancies in HBsAg-positive participants, the increases being most pronounced in those who were HBV DNA positive and for NHL. If confirmed, these results may have implications for increased cancer screening in HIV-positive subjects with chronic HBV infection.

Progress Toward Hepatitis B Control - World Health Organization European Region, 2016-2019.

In 2019, an estimated 14 million persons in the World Health Organization (WHO) European Region* (EUR) were chronically infected with hepatitis B virus (HBV), and approximately 43,000 of these persons died from complications of chronic HBV infection (1). In 2016, the WHO Regional Office for Europe set hepatitis B control program targets for 2020, including 1) ≥90% coverage with 3 doses of hepatitis B vaccine (HepB3), 2) ≥90% coverage with interventions to prevent mother-to-child transmission (MTCT) of HBV,† and 3) ≤0.5% prevalence of HBV surface antigen (HBsAg)§ in age groups eligible for vaccination with hepatitis B vaccine (HepB) (2-4). This report describes the progress made toward hepatitis B control in EUR during 2016-2019. By December 2019, 50 (94%) of 53 countries in EUR provided routine vaccination with HepB to all infants or children aged 1-12 years (universal HepB), including 23 (43%) countries that offered hepatitis B birth dose (HepB-BD) to all newborns. In addition, 35 (73%) of the 48 countries with universal infant HepB vaccination reached ≥90% HepB3 coverage annually during 2017-2019, and 19 (83%) of the 23 countries with universal birth dose administration achieved ≥90% timely HepB-BD coverage¶ annually during that period. Antenatal hepatitis B screening coverage was ≥90% in 17 (57%) of 30 countries that selectively provided HepB-BD to infants born to mothers with positive HBsAg test results. In January 2020, Italy and the Netherlands became the first counties in EUR to be validated to have achieved the regional hepatitis B control targets. Countries can accelerate progress toward hepatitis B control by improving coverage with HepB and interventions to prevent MTCT and documenting achievement of the HBsAg seroprevalence target through representative serosurveys or, in low-endemicity countries, antenatal screening.

Hepatitis B surface antigen seroprevalence among children in the Philippines, 2018

The World Health Organization Western Pacific Region (WPR) set a hepatitis B virus (HBV) control target to achieve HBV surface antigen (HBsAg) prevalence of <1% among children aged 5 years by 2017. The estimated HBsAg prevalence in the Philippines among adults was 16.7% during the pre-vaccine era. We estimated the HBsAg seroprevalence among children aged 5–7 years to measure the impact of vaccination.We conducted a household serosurvey, using a three-stage cluster survey methodology (provinces, clusters, and households). We estimated HBsAg prevalence using a rapid, point-of-care HBsAg test and calculated vaccination coverage by reviewing vaccination records or by caregiver recall. A questionnaire was administered to assess demographic variables for the child and family. We assessed the association between chronic HBV infection, vaccination coverage, and demographic variables, accounting for the complex survey design.Of the 2178 children tested, HBsAg was detected in 15 children [0.8%, 95% confidence interval (CI): 0.4, 1.7]. Only two of the HBsAg-positive children had been fully vaccinated against HBV. Based on documented vaccination or caregiver recall for the survey population, hepatitis B vaccine birth dose (HepB-BD) coverage was 53%, and the third dose hepatitis B vaccination (HepB3) coverage was 73 percent. Among the 1362 children with documented HepB-BD, timely HepB-BD coverage (given within 24 h of birth) was 43%; children born outside a health facility were less likely to receive a timely HepB-BD than those born in a health facility (adjusted odds ratio 0.10, 95% CI: 0.04, 0.23).HBsAg prevalence among children in the Philippines has decreased compared to the prevalence among adults in the pre-vaccination era. Strategies to further reduce HBsAg prevalence include ensuring that all children, whether born in health facilities or at home, receive a timely HepB-BD, and increasing HepB-BD and HepB3 coverage to reach the WPR goals of ≥95% coverage.

Seroprevalence of Hepatitis B Virus Surface Antigen (HBsAg) in Patients Visiting Teaching Hospital of Jumla, Nepal

Background: Hepatitis B Virus (HBV) infection is a foremost global health problem. In the context of Nepal, the prevalence of HBV infection is found to be low, 0.9% (1.1% in males and 0.5% in females), though a high prevalence of ≥8% is shown among the population in the mountainous region by several studies. The epidemiology of HBV infection in the population of Jumla is not well-known. This study aimed to find out the seroprevalence of HBV surface antigen (HBsAg) in patients visiting Karnali Academy of Health Sciences Teaching Hospital (KAHS-TH), Jumla, Nepal.&#x0D; Methods: The cross-sectional study was conducted in people visiting KAHS-TH, Jumla for testing HBsAg from 1st April 2018 to 31st March 2019. The samples collected were tested for HBsAg by using the Rapid HBsAg test kit. All positive cases were further tested by the Chemiluminescence (CLIA) method for HBsAg. The data entry was done in Microsoft Excel. After transferring the data into SPSS version 16, data analysis was done.Results: In this study, 1704 individuals were screened during the period. Overall 53 (3.11%) were HBsAg positive. Among the total of 506 males and 1198 females, 22 (4.34%) males and 31 (2.58%) females were positive for HBsAg. The highest prevalence (8.1%) was observed in the age group of 40– 45 years. But the prevalence rate is zero in 0-5 years age group and above 65 years of age.&#x0D; Conclusion: The HBV infection was higher in Jumla as compared to that of the overall prevalence of Nepal. Males were highly infected than females and the middle age group was at the high-risk of HBV infection.

Seroprevalence of chronic hepatitis B virus infection and immunity to measles, rubella, tetanus and diphtheria among schoolchildren aged 6–7 years old in the Solomon Islands, 2016

The Western Pacific Region (WPR) established a goal to decrease chronic hepatitis B virus (HBV) infection among children to <1% and to achieve ≥95% hepatitis B vaccine birth dose (HepB-BD) and ≥95% three-dose (HepB3) coverage by 2017. In 2016, we conducted a national serosurvey in the Solomon Islands among 6–7-year-old school children to assess progress towards the control goal and immunity to measles, rubella, tetanus and diphtheria. Eighty schools were selected systematically proportional to their 6–7-year-old population; all 6–7-year-olds were enrolled. We collected basic demographic information and vaccination history. Children were tested for HBV surface antigen (HBsAg) using a rapid test, and for immunity to measles, rubella, tetanus, and diphtheria using a multiplex bead assay. In total, 1,249 out of 1,492 children (84%) were enrolled, among whom 1,169 (94%) underwent HBsAg testing and 1,156 (93%) provided dried blood spots. Almost 80% (n = 982) of enrolled children had vaccination cards, among whom 59% (n = 584) received a timely HepB-BD (within 24 hours of birth), 95% (n = 932) received HepB3, and >90% received vaccines for diphtheria, tetanus, and measles (rubella vaccine was not available at the time). HBsAg prevalence was 3.1% (95% confidence interval (CI): 2.0%–4.9%), with 55% of identified cases from one province. Among 982 children with vaccination cards, HBsAg prevalence was higher among children who had not received a timely HepB-BD and at least two HepB doses compared to those who had (4% vs. 2%). Of 1,156 tested children, immunoprotection estimates were 99% (95% CI: 98%–99%) for measles, 99% (95% CI: 97%–100%) for rubella, 85% (95% CI: 83%–87%) for tetanus, and 51% (95% CI: 47%–55%) for diphtheria. Improving timely HepB-BD coverage and maintaining high HepB3 coverage could help Solomon Islands reach the regional HBV control goal. Low immunity to tetanus and diphtheria suggests the need to introduce booster doses to ensure long-term protection.

Seroepidemiology of Hepatitis B in the Democratic Republic of the Congo.

Hepatitis B virus (HBV) is endemic throughout Africa, but its prevalence in the Democratic Republic of the Congo (DRC) is incompletely understood. We used dried blood spot (DBS) samples from the 2013 to 2014 Demographic and Health Survey in the DRC to measure the prevalence of HBV using the Abbott ARCHITECT HBV surface antigen (HBsAg) qualitative assay. We then attempted to sequence and genotype HBsAg-positive samples. The weighted national prevalence of HBV was 3.3% (95% CI: 1.8-4.7%), with a prevalence of 2.2% (95% CI: 0.3-4.1%) among children. Hepatitis B virus cases occurred countrywide and across age strata. Genotype E predominated (60%), and we found a unique cluster of genotype A isolates (30%). In conclusion, DBS-based HBsAg testing from a nationally representative survey found that HBV is common and widely distributed among Congolese adults and children. The distribution of cases across ages suggests ongoing transmission and underscores the need for additional interventions to prevent HBV infection.

Antiviral therapy predicts the outcomes following resection of hepatocellular carcinoma in patients negative for HBV DNA: a propensity score matching analysis

BackgroundThe effect of antiviral therapy (AVT) on clinical outcomes in patients with hepatocellular carcinoma (HCC) who are seronegative for hepatitis B virus (HBV), defined as HBV DNA < 100 IU/ml prior to surgical resection, is unknown. The main purpose of this study was to evaluate the possible value of AVT in this cohort of patients.MethodsFrom January 2006 to January 2013, 161 HCC patients with positive serum tests for HBV surface antigen (HBsAg) but negative tests for HBV DNA who had undergone hepatectomy were included and analyzed. Propensity score matching (PSM) was used to balance the heterogeneity in baseline characteristics.ResultsAll patients were divided into the following two groups: the AVT group (n = 73, 45.34%) and the non-AVT group (n = 88, 54.66%). HBV reactivation occurred in 20 patients in the non-AVT group (22.73%) but in only 2 patients in the AVT group (2.74%, p < 0.001). After PSM, the 1-, 2-, and 3-year recurrence-free survival (RFS) rates in the AVT group and the non-AVT group were 78.38%, 72.97%, and 62.16% and 81.08%, 72.97%, and 72.97%, respectively (p = 0.564); the 1-, 2-, and 3-year overall survival (OS) rates were 97.30%, 97.3%, and 91.89% and 94.59%, 94.59%, and 86.49% in the AVT group and non-AVT group, respectively (p = 0.447).ConclusionsAntiviral therapy can reduce HBV reactivation but is not correlated with a significant increase in postoperative RFS and OS in HCC patients with HBV DNA levels < 100 IU/ml.

HIV coinfection among persons diagnosed with hepatitis B in England in 2008-2014.

The aim of the study was to estimate HIV prevalence among persons with hepatitis B virus (HBV) infection in England and to examine associated risk factors. Persons aged ≥15years with an HBV surface antigen (HBsAg) test reported to Public Health England (PHE) sentinel surveillance during 2008-2014 were linked to the PHE national HIV/AIDS database. Coinfection was defined as an HIV diagnosis prior to, or within 6months following, a positive HBsAg test. During 2008-2014, 2149933 persons were tested for HBsAg and 3.9% (1129 of 28789) of HBsAg-positive persons were HIV positive. The probable route of HIV infection was heterosexual exposure for 95.3% of female patients and 32.3% of male patients, with 61.5% of male patients reporting sex between men. Among African-born coinfected persons, 84% probably acquired HIV there. Predictors of HIV positivity included older age [adjusted odds ratio (aOR) 1.1] and being of black ethnicity (aOR 15.5 for males; aOR 16.4 for females) or being male and of white ethnicity (aOR 8.2) compared with being female and of white ethnicity. HIV coinfection was more likely when HBV was diagnosed in sexual health (aOR 55.0), specialist liver (aOR 6.7), emergency department (aOR 5.3) and renal services (aOR 2.8) compared with general practice. Most (60.4%; 682 of 1129) coinfected persons were diagnosed with HIV infection > 6months before HBV diagnosis. Persons testing positive for HBsAg had a low HIV infection rate and fell largely into two groups: those of black ethnicity with probable Africa-acquired infections and white men who have sex with men (MSM) with probable UK-acquired infections. Findings reinforce existing recommendations to sustain and improve both HBV testing of migrants from HBV-prevalent countries and vaccination among HIV-positive MSM. Findings also support blood-borne virus testing in sexual health services and emergency departments.

Diagnostic accuracy of serological diagnosis of hepatitis C and B using dried blood spot samples (DBS): two systematic reviews and meta-analyses

BackgroundDried blood spots (DBS) are a convenient tool to enable diagnostic testing for viral diseases due to transport, handling and logistical advantages over conventional venous blood sampling. A better understanding of the performance of serological testing for hepatitis C (HCV) and hepatitis B virus (HBV) from DBS is important to enable more widespread use of this sampling approach in resource limited settings, and to inform the 2017 World Health Organization (WHO) guidance on testing for HBV/HCV.MethodsWe conducted two systematic reviews and meta-analyses on the diagnostic accuracy of HCV antibody (HCV-Ab) and HBV surface antigen (HBsAg) from DBS samples compared to venous blood samples. MEDLINE, EMBASE, Global Health and Cochrane library were searched for studies that assessed diagnostic accuracy with DBS and agreement between DBS and venous sampling. Heterogeneity of results was assessed and where possible a pooled analysis of sensitivity and specificity was performed using a bivariate analysis with maximum likelihood estimate and 95% confidence intervals (95%CI). We conducted a narrative review on the impact of varying storage conditions or limits of detection in subsets of samples. The QUADAS-2 tool was used to assess risk of bias.ResultsFor the diagnostic accuracy of HBsAg from DBS compared to venous blood, 19 studies were included in a quantitative meta-analysis, and 23 in a narrative review. Pooled sensitivity and specificity were 98% (95%CI:95%–99%) and 100% (95%CI:99–100%), respectively. For the diagnostic accuracy of HCV-Ab from DBS, 19 studies were included in a pooled quantitative meta-analysis, and 23 studies were included in a narrative review. Pooled estimates of sensitivity and specificity were 98% (CI95%:95–99) and 99% (CI95%:98–100), respectively. Overall quality of studies and heterogeneity were rated as moderate in both systematic reviews.ConclusionHCV-Ab and HBsAg testing using DBS compared to venous blood sampling was associated with excellent diagnostic accuracy. However, generalizability is limited as no uniform protocol was applied and most studies did not use fresh samples. Future studies on diagnostic accuracy should include an assessment of impact of environmental conditions common in low resource field settings. Manufacturers also need to formally validate their assays for DBS for use with their commercial assays.

Hepatitis B virus testing and linkage to care in a Canadian urban tertiary referral centre: a retrospective cohort study.

Despite universal vaccination, chronic hepatitis B virus (HBV) infection remains a public health concern in North America owing to immigration. We aimed to characterize the number of people with a positive result of testing for HBV surface antigen (HBsAg) in Calgary, a large urban Canadian health care region, and to assess whether recommended laboratory tests and specialist consultation were done for those identified as HBsAg-positive. Based on laboratory and Alberta Health Services administrative data, we identified all adults (age > 18 yr) with a positive HBsAg test result from Jan. 1 to Dec. 31, 2014 within the Calgary Zone. Demographic and relevant laboratory data were extracted within 6 months of a positive HBsAg test result, and referral to hepatology (2011-2014) was identified from data on referral to a centralized clinic. Parametric and nonparametric statistical methods were used for analyses. We identified 1214 HBsAg-positive people (584 women [48.1%]; median age 44 [interquartile range (IQR) 36-55] yr). A total of 1192 people (98.2%) had alanine aminotransferase testing (median level 23 [IQR 16-34] U/L; 117 [9.8%] with elevated levels), 682 (56.2%) had testing for HBV DNA (median level 2.8 [IQR 2.1-3.8] logIU/mL), 630 (51.9%) had HBV e antigen testing (negative result in 548 [87.0%]), and 145 (11.9%) had HBV e antibody testing (positive result in 111 [76.6%]). Overall, 144 people (11.9%) received anti-HBV treatment, and 390 (32.1%) were referred to a hepatologist. Many HBsAg-positive people in Calgary did not receive the recommended laboratory assessments. The results highlight the necessity of continual public health efforts to screen for chronic HBV infection in Canada and to ensure adequate follow-up in order to reach the World Health Organization's goal of viral hepatitis elimination by 2030.

Prevalence of Hepatitis B Virus Infection among Pregnant Women Attending Antenatal Clinics in Vientiane, Laos, 2008-2014.

The Lao People's Democratic Republic (PDR) is still considered a highly endemic country for hepatitis B, mainly due to perinatal transmission of hepatitis B virus (HBV), despite efforts made since 2004 for universal immunization of newborns. The prevalence of HBV surface antigen (HBsAg) carriage in pregnant women is a relevant marker for the risk of mother-to-child HBV transmission. This study aimed to assess the changes in prevalence of HBV infection among pregnant women attending the Mahosot Prenatal Clinic (Vientiane Capital). Methods. A retrospective study was performed in the Mahosot Hospital Laboratory to collect and analyze all the results of HBsAg testing in pregnant women from 2008 to 2014. Results. Of a total of 13,238 tested women of mean age of 26 years, 720 women (5,44% [95 CI: 5.1–5.8%]) were found HBsAg positive, the annual prevalence ranging from 4.6% to 6.2%. A slight but steady and significant decrease in prevalence over the 7 years of the study could be documented. Conclusion. Although below the 8% hyperendemic threshold, the HBsAg prevalence observed in pregnant women in Vientiane reflects a high risk of HBV perinatal transmission and call for a widespread infant immunization with an HBV vaccine birth dose.

Occult Hepatitis B Infection in Hepatitis C Patients with Hematological Disorders

Background: Occult hepatitis B infection (OBI) is determined by finding hepatitis B virus (HBV) DNA in the liver cells of the patients with negative tests for HBV surface antigen. It is more common in patients with hepatitis C virus (HCV) infection which can be transmitted by blood transfusion and is frequently seen in hemophilia and thalassemia patients. Objectives: The aim of this study was to assess the prevalence of OBI among Iranian patients with hematological disorders (thalassemia, hemophilia and other coagulation factor deficiencies) infected with chronic hepatitis C (CHC). Methods: In this descriptive cross-sectional study, all patients with hematological disorders (thalassemia, hemophilia or other coagulation factor deficiencies) who had simultaneous CHC infection and were referred to the Tehran hepatitis center between 2009 and 2010 were enrolled. Occult hepatitis B infection identification was based on serum HBV-DNA tests. Data analysis was performed with SPSS software. Results: All patients were HBsAg-negative and HCV RNA-positive. Only 145 patients were evaluated for HBV DNA (126 male and 19 female patients). The mean age (SD) was 28.12 (8.6) years. Thirty-five patients had thalassemia, 95 patients had hemophilia, and 15 patients had coagulation factor deficiencies. Serum HBV-DNA was negative for all cases. Conclusions: Based on our results, it seems that there were no cases of OBI among chronic HCV-infected patients with thalassemia and bleeding disorders, particularly hemophilia. However, to improve decisions concerning OBI screening, especially in transfusion centers, and concerning the use of comprehensive screening methods, more original studies with more precise laboratory techniques and larger sample sizes are needed.

Characterization of the 3rd International Standard for hepatitis B virus surface antigen (HBsAg)

BackgroundHBsAg is the most important marker for laboratory diagnosis of HBV infection. Validation and quality control of HBsAg tests requires International Standards (IS). Recently the 2nd IS was replaced by the 3rd IS. Both IS are made from plasma-derived hepatitis B vaccines, but production and geographical origin are different. ObjectiveCharacterization of the HBsAg in the source material (SM) for the 3rd IS and comparison with the 2nd IS and native HBsAg. Study designThe SM was analyzed using solid-phase immunoassays, quantitative immune electrophoresis, ultracentrifugation, immunoblotting and HBV DNA sequencing. ResultsThe plasma-derived HBsAg of the SM originated from at least two different HBV strains, both of subgenotype (sgt) B4, typical for Vietnam. The HBsAg subtype was heterogeneous with ayw1 and adw2. The HBsAg concentration was 23,700 IU/ml as determined by solid-phase immunoassay; immune electrophoresis calibrated with sgt B2 revealed a concentration of 24,500 IU/ml while calibration with sgt D1 provided lower values. Proteins in the SM are heterogeneous in size containing only traces of preS. The protein subunits are partially cross-linked. ConclusionsThe antigenicity of the 3rd IS is suitable for HBsAg calibration in laboratory tests. In contrast to the 2nd IS, the 3rd IS is representative for a highly endemic region. Similar to the 2nd IS and different from native HBsAg, preS domains are depleted, protein subunits are partially cross-linked and the HBsAg particles are partially aggregated in the 3rd IS. The HBV subgenotype differences between the two IS may lead to variations in different quantitative assays.

Are current screening protocols for chronic hepatitis B virus infection adequate?

Chronic hepatitis B virus (HBV) infection screening usually includes only HBV surface antigen (HBsAg) testing; HBV core and surface antibody (anti-HBc, anti-HBs) assays, indicating resolved infection and immunity, are not routinely performed. Yet, serum HBV DNA is measurable in approximately 10% of HBsAg-negative/anti-HBc–positive cases, representing occult HBV infection (OBI). Patient blood samples from 2 Veterans Affairs medical center look-back investigations were screened for HBV infection using HBsAg enzyme immunoassays. Supplementary testing included anti-HBc and anti-HBs enzyme immunoassays. For anti-HBc–positive samples, HBV DNA testing was performed. Background OBI prevalence was further estimated at these 2 facilities based on HBV serology testing results from 1999-2012. Finally, a literature review was performed to determine OBI prevalence in the published literature. Of 1887 HBsAg-negative cohort patients, 98 (5.2%) were anti-HBc positive/anti-HBs negative; and 175 (9.3%), anti-HBc positive/anti-HBs positive. Six of 273 were HBV DNA positive, representing 0.3% of the total tested and 2.2% who were anti-HBc positive/anti-HBs negative or anti-HBc positive/anti-HBs positive. Among 32,229 general population veterans at these 2 sites who had any HBV testing, 4/108 (3.7%) were HBV DNA positive, none of whom were part of the cohort. In 129 publications with HBsAg-negative patients, 1817/1,209,426 (0.15%) had OBI. However, excluding blood bank studies with greater than 1000 patients, the OBI rate increased to 1800/17,893 (10%). OBI is not rare and has implications for transmission and disease detection. HBsAg testing alone is insufficient for detecting all chronic HBV infections. These findings may impact blood donation, patient HBV screening, follow-up protocols for patients assumed to have cleared the infection, and initiation of immunosuppression in patients with distant or undetected HBV.

The estimation of prevalence and risk factors of hepatitis B virus infection among blood donors in Chengdu, China.

The reported positive rates of hepatitis B virus surface antigen (HBsAg) among Chinese blood donors generally do not include data from pre-donation rapid tests. The aim of this study was to estimate the prevalence of serologic markers for HBsAg and risk factors among blood donors from Chengdu, China. From April 2010 to March 2011, a total of 16,875 blood donors were enrolled. Data from HBsAg tests before and after donations were collected to estimate the prevalence of HBsAg. A case-control study was conducted in 265 unique HBsAg-positive blood donors and 530 seronegative donors between January 2011 and October 2012. The odds ratio (OR) and 95% confidence interval (CI) were calculated using conditional logistic regression. The population attributable risk (PAR) was estimated. The prevalence of HBsAg was 3.17% (95%CI, 2.91-3.43%). The following risk factors were associated with HBV infection: non-vaccination for HBV (OR = 4.236; 95%CI, 2.72-6.60%), razor sharing (OR = 2.370; 95%CI, 1.46-3.84%), dental treatment (OR = 1.714; 95%CI, 1.21-2.43%), acupuncture (OR = 1.983; 95%CI, 1.20-3.28%), a family history of HBV infection (OR = 2.257; 95%CI, 1.32-3.86%), and endoscopy (OR = 2.17; 95%CI, 1.04-4.51%). The PAR values of the risk factors were 42.77%, 31.78%, 13.68%, 6.18%, 6.09%, and 2.85%, respectively, and the total PAR was 68.78%. The prevalence of HBsAg among Chinese blood donors is still high. HBV vaccinations can provide protection. Blood contact from sharing instruments is still a high risk route of transmission for HBV. Immunization programs and behavioral interventions should be used to prevent blood donation infections and improve blood safety.

Sa1019 Incidence of Hepatitis B Surface Antigen and Hepatitis B Core Antibody in a Screening Population Undergoing Chemotherapy

Background: Reactivation of hepatitis B virus (HBV) infection is a well-recognized complication after immunosuppression from chemotherapeutic agents and can lead to significant morbidity and mortality. We previously reported 23 HBV reactivations in patients of diverse nationalities without association with a particular malignancy or medication. Our institution subsequently initiated a protocol in which all new patients receiving immunosuppressive therapy are screened for HBV and offered anti-viral prophylaxis. The aim of this study is to report the prevalence of HBV surface antigen (HBsAg) and HBV core antibody (HBcAb) positivity since the inception of this screening program.Methods:We conducted a prospective study of all patients at Memorial Sloan-Kettering Cancer Center who were started on immunosuppressive therapy and screened for HBV from May 2009 to November 1, 2012. Patients were screened using tests for HBsAg and HBcAb. If either of these were positive, PCR for HBV DNA was reflexively measured. Patient demographics --including type of malignancy-were recorded. Results: Between May 1 2009 and November 1 2012, 17183 patients met criteria for screening and 12,328 patients (median age 64 years [24-95], 54.4% male) were screened for HBV prior to initiation of immunosuppression (71.75% compliance). Testing revealed 78(0.6%) patients positive for both HbsAg and HbcAb (median age 58, 69.2% male).Of this group, 47/78 (60.26%) had detectable HBV DNA PCR (955766.7 mean, 521 median) .Primary diagnoses of these patients included lymphoma 6.4%, leukemia 2.6%, and myriad solid tumors 91.0%. In addition, 994 patients (8.1%) were negative for HBsAg and positive for HBcAb (median age 58, 53.2% male), Diagnoses among this group included 6.0% lymphoma, 2.0% leukemia and 92.0 % solid tumor. Of this group, 7 (0.7%) had detectable HBV DNA PCR ([41-1,740,000 IU/mL]). Conclusion: In our population screened for HBV prior to initiation of immunosuppression, we report a prevalence of 0.6% for HBsAg positive patients and 8.1% for HBsAg negative, HBcAb positive patients. Screening of these