Hepatitis B core antigen antibody as an indicator of a low grade carrier state for hepatitis B virus in a Saudi Arabian blood donor population

Global epidemiology of occult hepatitis B virus infections in blood donors, a systematic review and meta-analysis

This study aimed to assess the global prevalence of occult hepatitis B in blood donors. We searched PubMed, Web of Science, Global Index Medicus, and Excerpta Medica Database. Study selection and data extraction were performed by at least two independent investigators. Heterogeneity (I2) was assessed using the χ2 test on the Cochran Q statistic and H parameters. Sources of heterogeneity were explored by subgroup analyses. This study is registered with PROSPERO, number CRD42021252787. We included 82 studies in this meta-analysis. The overall prevalence of OBI was 6.2% (95% CI: 5.4–7.1) in HBsAg negative and anti-HBc positive blood donors. Only sporadic cases of OBI were reported in HBsAg negative and anti-HBc negative blood donors. The overall prevalence of OBI was 0.2% (95% CI: 0.1–0.4) in HBsAg negative blood donors. The prevalence of OBI was generally higher in countries with low-income economic status. The results of this study show that despite routine screening of blood donors for hepatitis B, the transmission of HBV by blood remains possible via OBI and/or a seronegative window period; hence there is a need for active surveillance and foremost easier access to molecular tests for the screening of blood donors before transfusion.

Occult Hepatitis B virus infection among HIV negative and positive isolated anti-HBc individuals in eastern Ethiopia

The absence of hepatitis B surface antigen (HBsAg) and the presence of antibody to hepatitis B core antigen (anti-HBc) in the blood of apparently healthy individuals may not indicate the absence of circulating hepatitis B virus (HBV) and might be infectious. Despite the risk of HBV transmission, there has been no report from Ethiopia examining this issue; therefore, this study determined occult HBV infection (OBI) among isolated anti-HBc (IAHBc) HIV negative and HIV positive individuals on ART in eastern Ethiopia. A total of 306 IAHBc individuals were included in this study. DNA was extracted, amplified, and detected from plasma using a commercially available RealTime PCR platform (Abbott m2000rt) following the manufacturer's instructions. Data were entered into EPI Data version 3.1, cleaned, and analyzed using Stata version 13. Descriptive analysis was used to calculate prevalence, summarize sociodemographic data and other factors. From the 306 IAHBc individuals (184 HIV positive and 122 HIV negative) included in the study, 183 (59.8%) were female of which 142 (77.6%) were within the reproductive age group. DNA extraction, amplified and detection was conducted in 224 individuals. The overall OBI prevalence was 5.8% (5.6% in HIV negative and 6% in HIV positive) among the IAHBc individuals. The HBV DNA concentration among the occult hepatitis B individuals was < 200 IU/mL, indicating a true occult. This study reported the burden of OBI, which pauses a significant public health problem due to the high burden of HBV infection in the country. OBI may cause substantial risk of HBV transmission from blood transfusion, organ transplantation as well as vertical transmission as screening is solely dependent on HBsAg testing.

Seroprevalence of HBV among Egyptian municipal solid waste workers

Background

Municipal solid waste workers (MSWWs) are potentially exposed to diverse hazards that are not merely a consequence of their occupation. Of particular concern are infectious diseases. The endemicity of hepatitis B virus (HBV) infection in Egypt suggests the possibility of disease transmission in MSWWs from improperly disposed hazardous materials found in the solid waste stream. To date, such transmission has not adequately been epidemiologically studied in Egypt.

Objective

To explore the seroprevalence of HBV among MSWWs in Egypt.

Methods

We conducted a descriptive cross-sectional study that included 1467 MSWWs recruited from the main municipality company in Alexandria, Egypt, in February 2018. The enrolled participants were categorized into two occupational groups (exposed; n = 1361 and non-exposed; n = 115) on the basis of their direct exposure to solid waste. The study procedure involved interviews using a predesigned questionnaire that covered general demographic information. Blood samples from all participants were tested for the hepatitis B surface antigen (HBsAg), a marker of active HBV infection, using a third-generation enzyme linked immunosorbent assay (ELISA).

Results

All MSWWs were male and had a mean age of 39.8 (±7.9) years. The majority were urban residents (72.8%) and engaged in solid waste collection (63.8%) or sorting (13.6%). The overall seroprevalence of active HBV infection was 1.5%. In total, 3.8% of the workers received the compulsory HBV vaccine during their infancy, meaning approximately 96.2% of the participants were at risk for HBV infection. Evaluating the availability and use of personal protective equipment revealed that most of the workers were provided with and wore overalls but not safety shoes, protective gloves, face masks, or helmets.

Conclusion

The present work suggests the possible transmission of HBV in workers exposed to municipal solid waste. This result necessitates the initiation of prophylactic HBV immunizations and the consideration of safer techniques for waste management.

Prevalence of antibody to hepatitis B core antigen among hepatitis B surface antigen-negative blood donors in Ilorin, Nigeria: A cross-sectional study

BACKGROUND

Post-transfusion hepatitis occurs even with stringent donor selection criteria and screening for hepatitis B surface antigen (HBsAg). The objective of this study was to determine the prevalence of antibody to hepatitis B core antigen (anti-HBc) in HBsAg-negative blood donors.

METHODS

This was a cross-sectional study in which 200 HBsAg-negative blood donors were recruited. Screening for viral markers was done using both a rapid test kit and enzyme-linked immunosorbent assay (ELISA) for anti-HBc IgM. Quantitative and qualitative analysis of anti-HBc IgM was done by "capture" enzyme immunoassay using DIA.PRO HBc IgM test kits. The other viral markers were investigated using one step cassette style HBV tests. SPSS version 16 was used for data analysis. A P-value of 0.05 or less was considered significant.

RESULTS

There were 190 male (95%) and 10 female (5%) blood donors, with a mean age of 31.7 ± 7.9 years. The prevalence of anti-HBc IgM was 4%. The other viral markers (HBeAg, anti-HBeAg, anti-HBs and total anti-HBc) had a prevalence of 1.5%, 23%, 2.5%, and 32.5%, respectively.

CONCLUSIONS

The prevalence of anti-HBc IgM in this study was high, and this supports the fact that screening blood donors for HBsAg alone is not sufficient to prevent transmission of HBV.

Prevalence and characterization of occult hepatitis B infection among blood donors in central Saudi Arabia

OBJECTIVES

To evaluate the prevalence of occult hepatitis B viral infections (OBIs)  among blood donors considering the clinical and epidemiological importance of identifying OBIs.

METHODS

A cross-sectional study conducted at King Khalid University Hospital, Riyadh, Saudi Arabia between January 2011 and January 2012. Blood donors (n=8501) were screened for Hepatitis B virus surface antigen (HBsAg) and hepatitis B core antibodies (HBcAb). All HBsAg-negative and HBcAb-positive samples were tested further for hepatitis B surface antibodies (HBsAb), hepatitis B virus (HBV)-DNA, and HBV genotyping.  

RESULTS

Of the 8501 serum samples tested, 56 (0.7%) were positive and 8445 (99.3%) were negative for HBsAg. Among the HBsAg-negative samples, 198 (2.3%) were positive for HBcAb and these patients were suspected to have OBIs. Among the HBcAb-positive samples, 119 (60.1%) were positive while 79 (39.9%) were negative for HBsAb. Analysis of HBV-DNA for the suspected OBIs showed that 17 out of 198 samples (8.6%) yielded positive results, and all of them were HBsAb-negative. The viral load was low (less than 20-186 IU/mL) in all OBIs. Hepatitis B virus genotyping showed that 15 out of 17 samples (88.2%) were genotype D, and the other 2 samples (11.8%) were genotype E. 

CONCLUSION

The prevalence of OBIs among blood donors in Riyadh was 0.2%. Therefore, it is recommended that HBV molecular testing should be incorporated with serological assays for screening of blood donors.

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.

Intra-familial Transmission of Hepatitis B virus Infection in Zahedan

BACKGROUND

The household transmission of hepatitis B virus (HBV) is a major health problem. The prevalence rate of this infection is reported about 11% to 57% among family members of HBsAg carriers.

OBJECTIVES

This study was conducted to evaluate serological determinants of chronic hepatitis B infection, especially HBsAg positivity, among family members of asymptomatic HBsAg positive carriers in Zahedan (Southeast of Iran).

PATIENTS AND METHODS

In a cross-sectional study, data were collected from the total number of 454 HBsAg positive cases and 1817 members of their family by trained interviewers and a validated questionnaire. In addition, blood samples were obtained and titrated to detect serologic markers of hepatitis B. All subjects were recruited following informed consent to the study.

RESULTS

In total, 454 chronic HBsAg carriers (66% male) with mean age of 36 ± 10 years and 1817 of their family members were included in the study. The prevalence rate of HBsAg and HBcAb positivity among household members were 19.3% (n = 351) and 51% (n = 573), respectively. The frequency of HBV markers was different by age groups. The highest prevalence rate of HBsAg (34.9%) and HBcAb (31.9%) positivity were found in the age group of 21-30 years old. Importantly, the mothers of index cases had the highest prevalence of HBsAg positivity compared to their spouses who had the lowest proportion (53.2% vs. 8.4%, P < 0.001).

CONCLUSIONS

In family members, HBsAg positivity was four times greater than the general indigenous population. Considering the importance of close contacts for transmission, it was more prevalent in mothers of index cases compared to their spouses, suggesting more efficient mother-to-child than sexually transmission of HBV. It was also more prevalent in those having a history of hepatitis B in their maternal family compared to those with paternal one, probably due to more efficient transmission from infected mothers to children. The lower prevalence of HBsAg positivity in lower age groups could be attributed to vaccination of Iranian infants since 1993 and the screening of HBsAg positive mothers during the last two decades.

Significance of detecting anti-HBc among Egyptian male blood donors negative for HBsAg

BACKGROUND

Screening for hepatitis B virus surface antigen (HBsAg) reduces the risk of transfusion-transmitted hepatitis B viral (HBV) infection. However, the absence of HBsAg in the blood of apparently healthy individuals may not be sufficient to ensure the lack of circulating HBV. Blood containing anti-hepatitis B core antibody (anti-HBc) without detectable presence of HBsAg might be infectious; therefore, screening for anti-HBc has been implemented in some countries resulting in a decrease in the risk of post-transfusion HBV infection.

AIM

To study the seroprevalence of anti-HBc. The relationship between anti-HBc positivity and the presence of circulating HBV among healthy blood donors negative for HBsAg will be helpful to decide whether supplemental testing may bring additional safety to blood products.

MATERIAL AND METHODS

A total of 1026 serum samples collected from HBsAg-negative Egyptian healthy male donors were tested for the presence of anti-HBc (both IgM and IgG types) using the competitive enzyme-linked immunosorbent assay technique. Anti-HBc-positive samples were subjected to real-time polymerase chain reaction to confirm the presence of HBV DNA.

RESULTS

Of the 1026 samples tested, 80 (7·8%) blood samples were found to be reactive to anti-HBc. Of those, HBV DNA was detected in five of the samples (6·25%). The levels of detected viraemia were variable among the five donors.

CONCLUSION

This study shows the insufficient effectiveness of HBsAg screening in protecting blood recipients from HBV infection. Inclusion of anti-HBc testing should be considered in the screening of blood donors.

Lack of occult hepatitis B virus infection among blood donors with isolated hepatitis B core antibody living in an HBV low prevalence region of Iran

BACKGROUND

Occult hepatitis B virus (HBV) infection in blood donors is considered a potential threat for the safety of the blood supply, however conclusive studies on this issue are lacking. The aim of this study was to assess the occult HBV infection in blood donors with isolated hepatitis B core antibody (anti-HBc) living in the city of Arak, in the Central Province of Iran, as a low prevalence region for HBV.

METHODS

A total of 531 voluntary blood donors in Arak, Iran were included in this study. Hepatitis B surface antigen (HBsAg), hepatitis B surface antibody (anti-HBs), anti-HBc, and hepatitis C antibody (anti-HCV) were tested in all subjects. The presence of HBV-DNA was determined quantitatively in plasma samples of cases with isolated anti-HBc (HBsAg-negative, anti-HBs-negative, and anti-HBc-positive) by real-time PCR using the artus HBV RG PCR kit on the Rotor-Gene 3000 real-time thermal cycler.

RESULTS

Of 531 subjects enrolled in this study, 11 (2.1%, 95% confidence interval 0.8-3.2%) had isolated anti-HBc. HBV-DNA was not detected in any of the cases with isolated anti-HBc.

CONCLUSIONS

Our study showed that all the blood donors with isolated anti-HBc were negative for HBV-DNA, and occult HBV infection did not occur in the blood donors of this low prevalence region for HBV infection.

Isolated antibody to hepatitis B core antigen in patients with chronic hepatitis C virus infection

AIM: To evaluate the prevalence of isolated anti-HBc in patients with chronic hepatitis C virus (HCV) infection, and its relation to disease severity.

METHODS: We screened all patients with chronic HCV infection referred to King Faisal Specialist Hospital and Research Center for hepatitis B surface antigen (HBsAg), antibody to hepatitis B surface antigen (anti-HBs), and anti-HBc. One hundred and sixty nine patients who tested negative for both HBsAg and anti-HBs were included in this study.

RESULTS: Pathologically, 59 had biopsy-proven cirrhosis and 110 had chronic active hepatitis (CAH). Of these 169 patients, 85 (50.3%) tested positive for anti-HBc. Patients with CAH had significantly higher prevalence of isolated anti-HBc than patients with cirrhosis, 71 (64.5%) and 14 (23.7%) respectively (P < 0.001). Twenty-five patients were tested for HBV DNA by qualitative PCR. The test was positive in 3 of them (12%; occult HBV infection).

CONCLUSION: Isolated anti-HBc alone is common in Saudi patients with chronic HCV infection, and is significantly more common in those with CAH than those with cirrhosis. Therefore, a screening strategy that only tests for HBsAg and anti-HBs in these patients will miss a large number of individuals with isolated anti-HBc, who may be potentially infectious.

Epidemiology of HBV infection in Asian blood donors: Emphasis on occult HBV infection and the role of NAT

Hepatitis B virus (HBV) infection is endemic in many Asian countries. Among many transmission routes, transfusion is the one that should be prevented. The first major success in enhancing transfusion safety came with the implementation of hepatitis B surface antigen (HBsAg) in the early 1970s. However, the studies quoted in this review demonstrate that transmission by blood components negative for HBsAg can still occur in the acute phase of infection during the seronegative window period, or during chronic stages of infection (i.c. "occult" HBV infection, OHB). OHB is defined as the presence of HBV DNA in blood or liver tissues in patients negative for HBsAg, with or without any HBV antibodies. Because of limitations in current blood screening practices, OHB is an overlooked source of HBV transmission. For policy development on screening for HBV infection in blood donors, it would be useful to assess the relative contribution of the above two sources of transfusion-transmitted HBV infection from HBsAg-negative donations. New screening policy should be evaluated on the basis of available data or newly designed studies. While anti-HBc screening can climinate residual risk of occult HBV transmission by transfusion in low-endemic areas, it would not be practical in most parts of the world where the prevalence of anti-HBc is >10% as too many otherwise healthy donors will be ineligible. On the contrary, studies mentioned in this paper indicate that nucleic acid amplification test (NAT) or new HBsAg tests of enhanced sensitivity would be effective in the screening of blood donors for OHB in highly endemic countries. However, the cost-effectiveness of blood screening tests is a major concern in Asia. We therefore have systemically reviewed the literature on prevalence and infectivity of OHB in Asian countries and the possible role of NAT for identifying blood donors in the pre-HBsAg window phase or in later stages of OHB.

Evidence of occult hepatitis B virus infection among Omani blood donors: a preliminary study

OBJECTIVES

The aim of this study was to determine the prevalence of hepatitis B surface antigen (HBsAg), hepatitis B core antibodies (anti-HBc) and hepatitis B virus (HBV) DNA among a selected group of Omani blood donors.

MATERIALS AND METHODS

Two hundred HBsAg-negative donors were screened for anti-HBc. Those found to be positive were investigated for HBV DNA by polymerase chain reaction. HBsAg was retested on these sera following an immune complex dissociation technique.

RESULTS

HBsAg was present in 2.8% of the donors. Forty-one out of 200 (20.5%) HBsAg-negative donors were positive for anti-HBc. Eleven were positive for HBsAg after dissociation, whereas 8 gave readings just over the cutoff. HBV DNA was not detected in this group.

CONCLUSION

Findings indicate that testing donors for HBsAg alone is not sufficient to eliminate HBV from the blood supply in Oman.

Prevalence of seromarkers of HBV and HCV among blood donors in eastern Saudi Arabia, 1998-2001

The prevalence of serological markers of HBV and HCV were determined for blood donors in eastern Saudi Arabia. Between 1998 and 2001, 13,443 donors (10,778 Saudi and 2665 non-Saudi), were screened for HBsAg, anti-HBc Ab, and anti-HCV Ab using commercial kits. There was a steady decrease in the HBsAg (2.58 and 1.67%), anti-HBc rates (15.32 and 9.15%), and anti-HCV (1.04 and 0.59%) rates between 1998 and 2001, respectively. However, there was a marked difference between Saudi and non-Saudi donors with regard to anti-HBc (P < 0.001) and anti-HCV (P < 0.01), but not HBsAg prevalence rates in the same time period.

Occult hepatitis B virus infection: implications in transfusion

Hepatitis B virus (HBV) presents a higher residual risk of transmission by transfusion than hepatitis C virus (HCV) or human immunodeficiency virus (HIV). While most infectious blood units are removed by screening for hepatitis B surface antigen (HBsAg), there is clear evidence that transmission by HBsAg-negative components occurs, in part, during the serologically negative window period, but more so during the late stages of infection. Donations negative for HBsAg, but positive for HBV DNA, with or without the presence of HBV antibodies, correspond to 'occult' HBV infection (OBI). The frequency of OBI depends on the relative sensitivity of both HBsAg and HBV DNA assays. It also depends on the prevalence of HBV infection in the population. OBI may follow recovery from infection, displaying antibody to hepatitis B surface antigen (anti-HBs) and persistent low-level viraemia, escape mutants undetected by the HBsAg assays, or healthy carriage with antibodies to hepatitis B e antigen (anti-HBe) and to hepatitis B core antigen (anti-HBc). Over time, in the latter situation, anti-HBe and, later, anti-HBc may become undetectable. The critical question is whether or not OBI is infectious by transfusion. All forms have been shown to be infectious in immunocompromised individuals, such as organ- or bone marrow-transplant recipients. In immunocompetent recipients, there is no evidence that anti-HBs-containing components (even at low titre) are infectious. Anti-HBc only, with HBV DNA, can be associated with infectivity, as can rare cases of HBV DNA without any serological HBV marker. If HBV nucleic acid amplification technology (NAT) is considered, the OBI viral load would usually be < 500 IU/ml, making testing of plasma pools unsuitable unless the sensitivity of NAT significantly increases by genome enrichment or test improvement.

Occult hepatitis B virus infection

The detection of HBV DNA without HBsAg with or without the presence of HBV antibodies outside the acute phase window period defines occult HBV infection. This condition has been described in hepatocellular carcinoma (HCC), chronic hepatitis B, healthy HBV carriage and recovered infection, chronic hepatitis C and individuals without serological markers of HBV. The frequency of the diagnosis depends on the relative sensitivity of both HBsAg and HBV DNA assays. It also depends on the prevalence of HBV infection in the population. Occult HBV in blood donors has a wide range of potential origins within the natural history of the infection. It may originate from recovered infections with anti-HBs and persistent, low-level, viral replication, escape mutants undetected by the HBsAg assays or healthy chronic carriage. The last situation is mostly found with anti-HBc only. Over time, antibody markers may become undetectable leaving HBV DNA as the only marker of the infection. In all cases, the viral load is low, mostly below 10(4) IU/ml, often below 100 IU/ml. At these levels, nucleic acid testing (NAT) in pools is likely to be largely ineffective. Is occult HBV transmissible by transfusion? Carriers of anti-HBs or anti-HBc only were shown infectious in immunosuppressed organ or bone marrow transplant recipients. In immunocompetent recipients, there is no evidence that anti-HBs-containing components are infectious, even in low titre. Donations carrying anti-HBc only and HBV DNA can be infectious and this is a threat where anti-HBc is not screened. Anti-HBc screening identifies most occult HBV infection but not all. HBV NAT needs either extreme sensitivity or to be performed on individual donations to eliminate HBV DNA-containing units.