Poor sensitivity of rapid tests for the detection of antibodies to the hepatitis B virus: implications for field studies

Point-of-Care Testing for Hepatitis Viruses: A Growing Need

Viral hepatitis, caused by hepatitis A virus (HAV), hepatitis B virus (HBV), hepatitis C virus (HCV), hepatitis D virus (HDV), or hepatitis E virus (HEV), is a major global public health problem. These viruses cause millions of infections each year, and chronic infections with HBV, HCV, or HDV can lead to severe liver complications; however, they are underdiagnosed. Achieving the World Health Organization's viral hepatitis elimination goals by 2030 will require access to simpler, faster, and less expensive diagnostics. The development and implementation of point-of-care (POC) testing methods that can be performed outside of a laboratory for the diagnosis of viral hepatitis infections is a promising approach to facilitate and expedite WHO's elimination targets. While a few markers of viral hepatitis are already available in POC formats, tests for additional markers or using novel technologies need to be developed and validated for clinical use. Potential methods and uses for the POC testing of antibodies, antigens, and nucleic acids that relate to the diagnosis, monitoring, or surveillance of viral hepatitis infections are discussed here. Unmet needs and areas where additional research is needed are also described.

HCV elimination in a Swiss opioid agonist therapy programme - a cohort study

BACKGROUND

In opioid agonist therapy (OAT) programmes, chronic hepatitis C is highly prevalent and directly observed therapy guarantees optimal adherence. Since 2017, all patients with chronic hepatitis C in Switzerland can be treated with pangenotypic direct-acting antivirals irrespective of liver fibrosis stage. Until the end of 2021, however, prescription was restricted to infectious disease specialists, gastroenterologists and certain addiction specialists. Difficult venous access after long-term intravenous drug use and, in the case of referral to a specialist, difficulties keeping appointments are barriers to HCV diagnosis and treatment.

AIMS

To assess whether minimally invasive point-of-care tests and a "test-and-treat / vaccinate on-site" approach can improve human immunodeficiency virus (HIV) / hepatitis C virus (HCV) screening, HCV treatment uptake and immunity against hepatitis A/B.

METHODS

Since September 2018, an infectious disease specialist and a study nurse performed 4-weekly visits in the OAT programme "HAG" (heroin dispensation of the canton Aargau), offering HIV/HCV antibody rapid testing (20 min) and HCV RNA quantification (GeneXpert®, 60 min) from capillary blood, noninvasive liver fibrosis assessment (Fibroscan®, 5-10 min) and HCV treatment prescription on-site. Recommended venous blood draws for HAV/HBV serology and HAV/HBV vaccinations were performed by the staff of the "HAG". Project performance was assessed by annual cross-sectional chart review.

RESULTS

Of the 128 patients registered in April 2018, 79 (62%) were still present in May 2021. With 72 newly registered, a total of 200 patients could be assessed, of whom 129 (65%) were still present in May 2021. Between April 2018 and May 2021, the proportion ever tested for HIV antibodies increased from 79% (101/128) to 91% (117/129), the proportion ever tested for HCV antibodies from 83% (106/128) to 93% (120/129) and the proportion of those HCV antibody positive ever tested for HCV RNA tested from 89% (47/53) to 98% (56/57). The proportion with adequate HCV management (last HCV antibody test ≤1 year ago, if HCV antibody negative or last HCV RNA test ≤1 year ago, if HCV antibody-positive and RNA-negative) improved from 23% ([15 + 15]/128) to 80% ([55 + 48]/129). Overall, HCV treatment uptake increased from 60% (21/35) to 92% (55/60) and HCV RNA prevalence among the HCV antibody positives decreased from 38% (18/47) to 7% (6/84). Between 2018 and 2021, 19 non-cirrhotic chronic hepatitis C patients were successfully treated on-site (18 sustained virological responses [SVR] 12, 1 SVR4), with excellent adherence (≥93%) and, so far, no reinfection. The proportion with known HAV/HBV serostatus increased from 38%/51% to 64%/76%. Immunity against HAV/HBV improved from 19%/23% to 50%/57%.

CONCLUSION

Capillary blood point-of-care tests and a "test-and-treat / vaccinate on-site" approach remove crucial barriers to diagnosis and treatment, making hepatitis elimination in OAT programmes achievable. A high fluctuation rate requires HIV/HCV/HAV/HBV testing at admission, but also allows more patients to be screened.

Burden and Transmission Risks of Viral Hepatitis in Southern Ethiopia: Evidence Needed for Prevention and Control Measures

BACKGROUND

Hepatitis B virus (HBV) and hepatitis C virus (HCV) are significant causes of liver-associated morbidity and mortality for millions of people globally. Ethiopia is one of the viral hepatitis-endemic countries with no national strategy for surveillance and limited data. As such, this study aimed to investigated the extent and associated risk factors of HBV and HCV among community members in southern Ethiopia.

METHODS

A community-based cross-sectional study was conducted from January 2020 to August 2020. A structured questionnaire was used to collect behavioral and sociodemographic data. Serum samples were collected and assayed for seromarkers of HBV (HBsAg, anti-HBc, and anti-HBs) and HCV (anti-HCV) using ELISAs. In HBsAg-positive samples, HBV DNA was further quantified using RT-PCR. Data were entered into EpiData 3.1 and analyzed using SPSS 21.0. Descriptive statistics and logistic regression analysis were employed.

RESULTS

The study included 693 participants. Seromarkers for HBsAg, anti-HCV, anti-HBc, and anti-HBs were found to be 9.5%, 1.4%, 31.1%, and 14.3%, respectively. In 66 HBsAg positives, 57 (86.4%) had quantifiable HBV DNA. Prevalence of current HBV infection (HBsAg+, anti-HBc+, anti-HBs-) and lifetime exposure (positive for either HBsAg or anti-HBc) to HBV were 8.7% and 31.9%, respectively, and 63.1% of participants were vulnerable or had no evidence of prior HBV infection (HBsAg-, anti-HBc-, anti-HBs-). On multivariate logistic regression analysis, multiple sexual contacts, family history of hepatitis infection, alcohol consumption, and khat chewing were significantly associated with HBV. The seroprevalence of HBV was relatively high in this study area.

CONCLUSION

This study showed high prevalence of HBV infection, but low prevalence of HCV. This indicates that HBV is a major health problem in this community. Population-based surveillance, care, and treatment, as well as behavioral change and education programs, should be enhanced to minimize risk exposure.

Cross-sectional hospital-based study on the seroprevalence of hepatitis B virus markers among healthcare workers, NWR, Cameroon

BACKGROUND

Hepatitis B virus (HBV) infection is a major public health issue worldwide, with about 257 million people reported to be chronic carriers by the WHO fact sheet updated in 2018. HBV can be contracted via direct contact with infected body fluid and infection is almost always asymptomatic. Although healthcare workers (HCWs) are at high risk of HBV infection, little is known about the prevalence of the various HBV markers among HCWs in Cameroon. The present study was taken to evaluate the prevalence of different HBV serological markers among HCWs in the North-West Region of Cameroon.

METHODS

This cross-sectional hospital-based study was carried out between April and September 2017 during which 395 HCWs were recruited. The serum of the HCWs were tested for the presence of HBV core antibody, hepatitis B surface antibody, hepatitis B e antibody and hepatitis B surface antigen using Monalisa ELISA kits produced by BIO-RAD laboratories. Data were analysed using SPSS V.20.0.

RESULTS

Among the 395 participants, 270 (68.4%) of them were females, 187 (47.3%) had been exposed to HBV, 145 (36.7%) had resolved the infection, 42 (10.6%) were current HBV carriers, 10 (2.5%) were infective, 36 (9.1%) were vaccinated and 172 (43.5%) were still susceptible. Exposure to HBV, past infection and susceptibility were significantly associated with age while the rate of vaccination was significantly associated with the job of the HCW in the health facilities.

CONCLUSION

The prevalence of HBV exposure and infection among HCWs obtained in this study was high while the level of vaccination in this at-risk population was low. Adequate steps should be taken to sensitise this population on HBV and the vaccination procedure.

Point-of-Care Tests for Hepatitis B: An Overview

Despite the heavy disease burden posed by hepatitis B, around 90% of people living with hepatitis B are not diagnosed globally. Many of the affected populations still have limited or no access to essential blood tests for hepatitis B. Compared to conventional blood tests which heavily rely on centralised laboratory facilities, point-of-care testing for hepatitis B has the potential to broaden testing access in low-resource settings and to engage hard-to-reach populations. Few hepatitis B point-of-care tests have been ratified for clinical use by international and regional regulatory bodies, and countries have been slow to adopt point-of-care testing into hepatitis B programs. This review presents currently available point-of-care tests for hepatitis B and their roles in the care cascade, reviewing evidence for testing performance, utility, acceptability, costs and cost-effectiveness when integrated into hepatitis B diagnosis and monitoring programs. We further discuss challenges and future directions in aspects of technology, implementation, and regulation when adopting point-of-care testing in hepatitis B programs.

Prevalence of hepatitis B viruses and associated factors among pregnant women attending antenatal clinics in public hospitals of Wolaita Zone, South Ethiopia

Background

Hepatitis B virus (HBV) infection is a serious public health problem in sub-Saharan Africa pregnant women. HBV Infection has high tendency of vertical transmission and have adverse effect on both the mother and child. However, there is no evidence on prevalence of hepatitis B virus among pregnant women in Wolaita Zone. Therefore, this study aims to determine prevalence and associated factors of hepatitis B virus infection among pregnant attending Antenatal clinics of public Hospitals of Wolaita Zone.

Method

An institution based cross sectional study was conducted among pregnant women attending antenatal clinics of Wolaita Zone from October—November, 2018. Systematic random sampling was used to get respondents. A pretested, structured questionnaire was used to collect socio-demographic characteristics and other variables. In addition, 5 ml of venous blood was collected from each study participants and serum was tested for Hepatitis B surface antigen. Data was entered to Epidata 3.1 version and exported Statistical Package for Social Sciences Version 20.0 for descriptive and logistic regression analysis. All variables in bivariate analysis with p<0.25 were taken to multivariable analysis. P-value and Odds ratio with 95% CI was used to measure the presence and strength of the association respectively.

Result

The prevalence of Hepatitis B surface Antigen among pregnant women was 49(7.3%). History of multiple sexual partners (AOR = 2.675, 95%CI = 1.107–6.463), surgical procedure (AOR = 3.218, 95%CI = 1.446–7.163), genital mutilation (AOR = 2.72, 95% CI = 1.407–5.263), and tooth extraction (AOR = 2.049, 95%CI = 1.061–3.956) were statistically associated with HBV.

Conclusion and recommendation

Intermediate endemicity of Hepatitis B Virus (7.3%) was observed among mothers attending antenatal clinics of Wolaita Zone. History of tooth extraction, history of surgical procedure, history of genital mutilation and history multiple sexual partners were factors associated with acquisition of Hepatitis B Virus infection. Therefore, we recommend that the health education programs should be done to avoid traditional and non-sterile tooth extraction methods, female genital mutilation and avoiding having multiple sexual partner and its consequences to community and to raise the awareness of mothers attending antenatal clinics. Facilities should strictly follow sterile procedures in every surgical procedure.

A cross-sectional study on dental surgeons' immune status against hepatitis B virus in the Public Health System

Hepatitis B is a severe public health problem. The main world health centers have discussed it due to its pandemic proportion, high pathogenicity and infectivity. This study aimed to determine the immunization profile of dental surgeons - against hepatitis B virus (HBV) in the Public Health System (PHS) through the detection of anti-HBsAg antibodies by immunochromatography and associations with dental surgeons' social and educational profile, factors related to professional knowledge and practices. This is a cross-sectional study on the prevalence of vaccination and immune status to HBV in dentists of Sao Paulo State PHS. Data collection occurred in three stages: questionnaire application, analysis of adhesion to the vaccination protocol and anti-HBsAg tests. Statistical analysis used the Bivariate Analysis and the Binary Logistic Regression. From the total of 219 interviewees, 74.9% reported having received three doses of the vaccine, but 35.6% were not immune to HBV. The dependent variable was associated with years in the public service (years) (OR [Odds Ratio]=1.04; 95% CI 1.00-1.08); knowledge on the subject (OR=6.93; 95% CI 1.39-34.40); incorrect answer concerning the etiological agent of the disease (OR=2.60; 95% CI 1.30-5.22); ignorance on the number of vaccine doses that have been administered (OR=3.43; 95% CI 1.14-10.30); and less than three doses of the vaccine in the immunization schedule (OR=8.76; 95% CI 3.50-21.91). A considerable portion of professionals non-immune to the HBV were found. We concluded that knowledge, years of practice and completion of the vaccination schedule (three doses) affected dental surgeons' immune status to HBV.

Seroprevalence and associated factors of hepatitis B virus infection among HIV-positive adults attending an antiretroviral treatment clinic at Wolaita Sodo University Referral Hospital

Background

Hepatitis B virus infection (HBV) constitutes major public health problems in sub-Saharan Africa from different infections occuring in HIV positive patients. Ethiopia is a part of sub-Saharan Africa with 1.5% adult HIV prevalence, and also belongs to the intermediate to high HBV prevalence category. Hence, this study aimed to measure the seroprevalence and associated factors of HBV infection among HIV-positive adults attending an antiretroviral treatment (ART) clinic at Wolaita Sodo University Referral Hospital.

Methods

An institution-based cross-sectional study was conducted from October 15 to December 10, 2017 using a systematic random sampling technique. After getting informed written consent, data were collected by a structured and interviewer-administered questionnaire. Venous blood was collected and centrifuged to separate serum. Hepatitis B surface antigen (HBsAg) was detected from serum using an advanced quality one-step rapid test kit. Data were entered into EpiData version 3.01 and exported to SPSS version 20. Summary statistics, bivariate analysis, and multivariate analyses were performed. The variables having significant association of P<0.05 in the multivariate logistic regression were taken as independent factors. OR and 95% CI were used to measure the strength of the association.

Results

A total of 442 study participants, 187 males and 255 females, were included in this study. Overall prevalence of HBsAg was 37 (8.4%). Family history of HBV (adjusted OR=8.83, 95% CI=2.56–30.49), multiple sexual partners (adjusted OR=7.08, 95% CI=2.29–21.9), and CD4 count <200 cells/μL (adjusted OR=15.34, 95% CI=4.77–49.3) were found to be significantly associated with HBsAg positivity.

Conclusion

The prevalence of HBsAg in this study was high. Family history of HBV, multiple sexual partners, and CD4 count <200 cells/μL were independently associated with HBsAg positivity. Therefore, screening for HBV is recommended before initiation of ART in HIV patients and providing appropriate treatment for co-infection. Furthermore, accurate information on risk factors for HBV transmission should be provided.

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Applicability of Oral Fluid and Dried Blood Spot for Hepatitis B Virus Diagnosis

Hepatitis B virus (HBV) is one of the major causes of chronic liver disease worldwide; however most of individuals are not aware about the infection. Oral fluid and dried blood spot (DBS) samples may be an alternative to serum to HBV diagnosis to increase the access to diagnosis in remote areas or high-risk groups. The main objective of this review is to give an insight about the usefulness of oral fluid and DBS for detecting HBV markers. Several groups have evaluated the detection of HBsAg, anti-HBc, and anti-HBs markers in oral fluid and DBS samples demonstrating 13 to 100% of sensitivity and specificity according different groups, sample collectors, and diagnosis assays. In the same way, HBV DNA detection using oral fluid and DBS samples demonstrate different values of sensitivity according type of collection, studied group, extraction, and detection methods. Thus, serological and molecular diagnostic tests demonstrated good performance for detecting HBV using oral fluid and DBS according some characteristics and could be useful to increase the access to the diagnosis of HBV.

A New ELISA to Overcome the Pitfalls in Quantification of Recombinant Human Monoclonal Anti-HBs, GC1102, by Commercial Immunoassays

Several methods for the quantification of human anti-HBs, an antibody to hepatitis B surface antigen (HBsAg), have been developed based on enzyme reaction, chemiluminescence, fluorescence, and radioactivity for application to human serum or plasma. Commercial anti-HBs immunoassay kits use a sandwich method in which a bridge is formed by the anti-HBs between a HBsAg immobilized solid matrix and the labeled HBsAg. However, this direct sandwich enzyme-linked immunosorbent assay (ELISA) is insufficient to accurately evaluate the activity of the human monoclonal anti-HBs, GC1102. As an alternative, we developed an indirect anti-HBs ELISA (anti-HBs qELISA_v.1) that improved detection of anti-HBs. In this current study, we further optimized this indirect method to minimize nonspecific binding of human serum, by employing incubation buffers containing animal serum, Tween 20, skim milk, and a low pH washing buffer. This new and improved method, termed anti-HBs qELISA_v.2, showed accurate quantification of plasma-derived hepatitis B immune globulin (HBIG) and was comparable to results obtained with commercial ELISA (r = 0.93) and RIA (r = 0.85) kits. Further, the GC1102 in human serum could be precisely measured using the anti-HBs qELISA_v.2 without limitations of nonspecific binding.

Performance of rapid diagnostic tests for the detection of anti-HBs in various patient populations

BACKGROUND

Rapid diagnostic tests (RDTs) represent an attractive alternative method to conventional diagnosis of hepatitis B virus (HBV) infection.

OBJECTIVE

The aim of the present study was to evaluate the diagnostic performance of commercially available RDTs for the detection of anti-HBs in various patient populations.

STUDY DESIGN

A total of 347 individuals, 198 positive and 149 negative for anti-HBs, were studied.

RESULTS

The specificity of RDT detection of anti-HBs in serum was 98.0%, 96.0% and 97.3% with TOYO® HBsAb Test, QuickProfile™ HBsAb test and QuickProfile™ HBV-3 Panel test, respectively. The diagnostic sensitivity varied between 60.4% and 69.5%. The sensitivity of the three RDTs was markedly better when testing serum samples with an anti-HBs titer higher than 100IU/L, and reached 90% or more for an anti-HBs titer above 150IU/L.

CONCLUSIONS

This performance was disappointing because the assays were not sensitive enough to detect low antibody titers. Thus, these tests require further improvement before they can be widely used in clinical practice.