Hepatitis B virus surface antigen and anti-hepatitis C virus rapid tests underestimate hepatitis prevalence among HIV-infected patients

Point of care and oral fluid hepatitis B testing in remote Indigenous communities of northern Australia

Many Indigenous Australians in northern Australia living with chronic hepatitis B are unaware of their diagnosis due to low screening rates. A venous blood point of care test (POCT) or oral fluid laboratory test could improve testing uptake in this region. The purpose of this study was to assess the field performance of venous blood POCT and laboratory performance of an oral fluid hepatitis B surface antigen (HBsAg) test in Indigenous individuals living in remote northern Australian communities. The study was conducted with four very remote communities in the tropical north of Australia's Northern Territory. Community research workers collected venous blood and oral fluid samples. We performed the venous blood POCT for HBsAg in the field. We assessed the venous blood and oral fluid specimens for the presence of HBsAg using standard laboratory assays. We calculated the sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of the POCT and oral fluid test, using serum laboratory detection of HBsAg as the gold standard. From 215 enrolled participants, 155 POCT and 197 oral fluid tests had corresponding serum HBsAg results. The POCT had a sensitivity of 91.7% and specificity of 100%. Based on a population prevalence of 6%, the PPV was 100% and NPV was 99.5%. The oral fluid test had a sensitivity of 56.8%, specificity of 98.1%, PPV of 97.3% and NPV of 65.9%. The venous blood POCT has excellent test characteristics and could be used to identify individuals with chronic HBV infection in high prevalence communities with limited access to health care. Oral fluid performance was suboptimal.

Hepatitis B and C in the adult population of Bissau, Guinea-Bissau: a cross-sectional survey

OBJECTIVE

Hepatitis B virus (HBV) and hepatitis C virus (HCV) are prevalent in West Africa. To address the WHO 2030 goals of a 90% reduction in incidence and a 65% reduction in mortality for both infections, we assessed the prevalence of HBV and HCV from surveys in the general population.

METHODS

Participants in this cross-sectional survey were included from randomly selected houses in a demographic surveillance site in Bissau, Guinea-Bissau. Participants were interviewed and had a blood sample drawn for viral analyses (HBsAg, anti-HBs, anti-HBc, anti-HCV and HCV RNA). Risk factors of HBV and HCV infection were determined by binomial regression adjusted for sex and age.

RESULTS

A total of 2715 participants were included in this study. The overall HBsAg prevalence was 18.7% (95% CI: 17.3-20.2%). HBsAg was associated with male sex (adjusted risk ratio (aRR): 1.64), and prevalence decreased with age >34 years. HBV exposure was found in 91.9% of participants. Although 72.6% of individuals without sexual debut had been exposed to HBV, ever engaging in a sexual relationship was associated with higher risk of HBV exposure (aRR 1.18). The anti-HCV prevalence was 0.5% (95% CI: 0.3-0.9%), and 78.6% of those had detectable HCV RNA. Risk factors for anti-HCV sero-positivity were age above 55 (aRR 10.60), a history of blood transfusion (aRR 5.07) and being in a polygamous marriage (aRR 3.52).

CONCLUSION

In Guinea-Bissau initiatives to implement treatment and widespread testing are needed to reach the WHO 2030 goals.

Hepatitis B infection and risk factors among children living with HIV in Yaounde, Cameroon: an integrated management

Background

The endemicity of hepatitis B virus (HBV) prompted the systematic immunization of newborns in Cameroon since 2005. In the frame of a considerable burden of HIV/HBV co-infection (17.5%), monitoring HBV among children living with HIV (CLHIV) would guide toward HIV/HBV integrated paediatric care. We sought to ascertain the prevalence and determinants of HBV infection in the population of CLHIV and performance of commonly used rapid diagnosis tests (RDTs).

Methods

Cross-sectional study conducted from February through June 2017 in a subset of CLHIV ≤15 years old at the Essos Hospital Centre, Yaounde, Cameroon. HBV was tested by HBsAg ELISA sandwich in duplicates for each sample, and the mean optical density was calculated. The Determinants of HBV-prevalencewere evaluated, and p < 0.05 was the significance threshold. The performance of two HBV RDTs (Diaspot vs. HBV-5) was evaluated in comparison to ELISA (used as gold standard).

Results

Of the 83 CLHIV enrolled (54.2% female, mean age 8.7 [±3.8] years, 60% vaccinated against HBV, all breastfed), HBV-prevalence was 2.41% (2/83). HBV-positivity was significantly associated with unknown maternal HBV status (2.9% [2/69] vs. 0.0% [0/14], p = 0.0097) and vaginal delivery (2.4% [2/82] vs. 0.0% [0/1], p = 0.0018). Moreover, the most likely to be positive were aged 11 and 15 years, and had experienced neither anti-HBV vaccination nor anti-HBV serum administration, and both had not been treated with any antiseptic solution at birth. Regarding the performance of Diaspot vs. HBV-5 respectively, sensitivity was 100% (2/2) vs. 50% (1/2), while specificity was 100% (45/45) vs. 97.8% (44/45); positive and negative predictive values of Diaspot versus HBV-5 were respectively 100% (2/2) and 100% (45/45) versus 50% (1/2) and 97.8% (44/45).

Conclusion

HBV-infection in the population of CLHIV appears at a moderate prevalence, suggesting a decreased burden likely due to preventive measures including the wide vaccine coverage. Focusing on mothers with unknown HBV status and promoting safer delivery mode (caesarean section) for HBV-positive motherswould contribute toward pediatric HBV elimination. In context of limited resources, Diaspot test appears more reliable to rollout HBV-infection in the population of CLHIV. As findings are limited to a small sample size, studies on a wider population would be relevant.

HTLV prevalence is no longer following the decreasing HIV prevalence - 20 years of retroviral surveillance in Guinea-Bissau, West Africa

BACKGROUND

The HIV-2 and HTLV-1 prevalences in Bissau have followed similar trends in surveys from 1996 and 2006 with HTLV-1 prevalences of 3.6% and 2.3%, respectively. However, following the introduction of antiretroviral treatment (ART) and informative campaigns about HIV, the epidemics may have shifted. To evaluate the current HTLV prevalence and the continued association with HIV, we performed a third survey.

METHODS

A cross-sectional survey was performed from November 2014 to February 2016. In total, 2583 participants were interviewed, tested for HIV, and had blood samples collected. Samples were analysed for anti-HTLV using chemiluminescence and immunoblot assays. We calculated the HTLV prevalence for 2016 and examined risk factors for HTLV and associations with HIV using binominal regression.

RESULTS

The prevalence of HTLV was 2.8% (71/2583), 1.5% (16/1,089) for men and 3.7% (55/1,494) for women. Old age, female sex, HIV-2 infection and sharing a house with a HTLV- infected person were strong risk factors for HTLV. In contrast to previous studies, we found a non-significant increase in prevalence among the 15-24 year-olds since 2006, supporting ongoing transmission.

CONCLUSIONS

The HTLV prevalence in Bissau showed a non-significant increase. We found evidence supporting continuous vertical and horizontal routes of transmissions.

Performance of point of care assays for hepatitis B and C viruses in chronic kidney disease patients

AIMS

Point of care testing (POCT) has been used for hepatitis B and C diagnosis in general population, but little is known about the influence of clinical conditions in the accuracy of these assays. This study aims to evaluate the performance of POCTs for detection of hepatitis B virus surface antigen (HBsAg) and antibodies to Hepatitis C Virus (anti-HCV) in Chronic Kidney Disease (CKD) patients.

METHODS

A total of 286 subjects were included in this study. HBsAg and anti-HCV were detected using commercial EIAs and four POCTs: HBsAg (WAMA Imuno-Rápido HBsAg and VIKIA HBsAg) and anti-HCV (DOLES HCV teste rápido and WAMA Imuno-Rápido anti-HCV) in serum and whole blood.

RESULTS

Using EIA, HBsAg and anti-HCV prevalence was 4.5% and 16.1% in CKD patients. HBsAg and anti-HCV POCTs had sensitivities from 92.3% to 100% and 84.8% to 89.1% while specificities were 99.3% to 100% and 99.2% to 99.6%, respectively. POCT using serum samples performed well compared with whole blood samples and true positive samples of POCTs had high optical density to cut-off (OD/CO) values compared with EIA.

CONCLUSIONS

This study demonstrates good performance of HBsAg and anti-HCV POCTs in CKD patients, especially in serum samples indicating low interference of this disease in the performance of these assays. POCTs could be an important tool for HBV and HCV screening in high-risk populations.

Diagnostic accuracy of tests to detect hepatitis B surface antigen: a systematic review of the literature and meta-analysis

BACKGROUND

Chronic Hepatitis B Virus (HBV) infection is characterised by the persistence of hepatitis B surface antigen (HBsAg). Expanding HBV diagnosis and treatment programmes into low resource settings will require high quality but inexpensive rapid diagnostic tests (RDTs) in addition to laboratory-based enzyme immunoassays (EIAs) to detect HBsAg. The purpose of this review is to assess the clinical accuracy of available diagnostic tests to detect HBsAg to inform recommendations on testing strategies in 2017 WHO hepatitis testing guidelines.

METHODS

The systematic review was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines using 9 databases. Two reviewers independently extracted data according to a pre-specified plan and evaluated study quality. Meta-analysis was performed. HBsAg diagnostic accuracy of rapid diagnostic tests (RDTs) was compared to enzyme immunoassay (EIA) and nucleic-acid test (NAT) reference standards. Subanalyses were performed to determine accuracy among brands, HIV-status and specimen type.

RESULTS

Of the 40 studies that met the inclusion criteria, 33 compared RDTs and/or EIAs against EIAs and 7 against NATs as reference standards. Thirty studies assessed diagnostic accuracy of 33 brands of RDTs in 23,716 individuals from 23 countries using EIA as the reference standard. The pooled sensitivity and specificity were 90.0% (95% CI: 89.1, 90.8) and 99.5% (95% CI: 99.4, 99.5) respectively, but accuracy varied widely among brands. Accuracy did not differ significantly whether serum, plasma, venous or capillary whole blood was used. Pooled sensitivity of RDTs in 5 studies of HIV-positive persons was lower at 72.3% (95% CI: 67.9, 76.4) compared to that in HIV-negative persons, but specificity remained high. Five studies evaluated 8 EIAs against a chemiluminescence immunoassay reference standard with a pooled sensitivity and specificity of 88.9% (95% CI: 87.0, 90.6) and 98.4% (95% CI: 97.8, 98.8), respectively. Accuracy of both RDTs and EIAs using a NAT reference were generally lower, especially amongst HIV-positive cohorts.

CONCLUSIONS

HBsAg RDTs have good sensitivity and excellent specificity compared to laboratory immunoassays as a reference standard. Sensitivity of HBsAg RDTs may be lower in HIV infected individuals.

Clinical presentation and opportunistic infections in HIV-1, HIV-2 and HIV-1/2 dual seropositive patients in Guinea-Bissau

BACKGROUND

Better understanding of HIV-2 infection is likely to affect the patient care in areas where HIV-2 is prevalent. In this study, we aimed to characterize the clinical presentations among HIV-1, HIV-2 and HIV-1/2 dual seropositive patients.

METHODS

In a cross-sectional study, newly diagnosed HIV patients attending the HIV outpatient clinic at Hospital Nacional Simão Mendes in Guinea-Bissau were enrolled. Demographical and clinical data were collected and compared between HIV-1, HIV-2 and HIV-1/2 dual seropositive patients.

RESULTS

A total of 169 patients (76% HIV-1, 17% HIV-2 and 6% HIV 1/2) were included in the study between 21 March 2012 and 14 December 2012. HIV-1 seropositive patients were younger than HIV-2 and HIV-1/2 seropositive patients, but no difference in sex was observed. Patients with HIV-1 and HIV-1/2 had a lower baseline CD4 cell count than HIV-2 seropositive patients (median CD4 cell count 185, 198 and 404 cells/μl, respectively (p value 0.001 and 0.05). HIV-1 seropositive patients had a lower BMI and a higher prevalence of weight loss, skin rash and productive cough than HIV-2 seropositive patients (p value 0.03, 0.002, 0.03 and 0.04). Only four cases (2%) of pulmonary tuberculosis (TB) were diagnosed. One patient (1/96, 1%) was tested positive for cryptococcal antigen.

CONCLUSION

HIV-1 and HIV-1/2 seropositive patients have lower CD4 cell counts than HIV-2 seropositive patients when diagnosed with HIV with only minor clinical and demographic differences among groups. Few patients were diagnosed with TB and cryptococcal disease was not found to be a major opportunistic infection among newly diagnosed HIV patients.

Validation of rapid point-of-care (POC) tests for detection of hepatitis B surface antigen in field and laboratory settings in the Gambia, Western Africa

Hepatitis B virus (HBV) infection is a leading cause of death in sub-Saharan Africa (SSA). Point-of-care tests for hepatitis B surface antigen (HBsAg) could be an ideal tool for a large-scale HBV screening/treatment program in SSA. Using data from the PROLIFICA (Prevention of Liver Fibrosis and Cancer in Africa) program, we conducted a cross-sectional study to assess the diagnostic accuracy of three point-of-care tests (Determine, Vikia, and Espline) for the detection of HBsAg in the field or a laboratory setting in the Gambia. In the field, we used finger-prick whole blood for the Determine and Vikia tests and dried blood spots for the reference standard test (AxSYM HBsAg enzyme-linked immunosorbent assay [ELISA]). In the laboratory we used serum for the Determine, Espline, and reference test (Architect chemiluminescent microparticle immunoassay). Of 773 participants recruited at the community and 227 known chronic HBV carriers (1,000 subjects in total), 293 were positive for HBsAg. The sensitivity and specificity of the Determine test were 88.5% and 100% in the field and 95.3% and 93.3% in the laboratory setting, respectively. The sensitivity and specificity were 90.0% and 99.8% for the Vikia test (in the field) and 93.9% and 94.7% for the Espline test (in the laboratory). There was no evidence that one kit was better than another. Most of the patients with false-negative results (18/19) were classified as inactive chronic carriers. In summary, the three point-of-care tests had acceptable ranges of diagnostic accuracy. These tests may represent accurate, rapid, and inexpensive alternatives to serology testing for the screening of HBV infection at field level in SSA.

Hepatitis C prevalence among HIV-infected patients in Guinea-Bissau: a descriptive cross-sectional study

OBJECTIVES

To estimate the prevalence and determine the clinical presentation of risk factors of hepatitis C virus (HCV) among HIV-infected patients in Bissau, Guinea-Bissau.

METHODS

In this cross-sectional study, we included individuals who had a routine blood analysis performed during the period April 28 to September 30, 2011. Patient samples were tested for HCV antibodies (anti-HCV) with a chemiluminescence test (Architect, Abbott, USA) and INNO-LIA HCV Score (Innogenetics, Belgium). HCV viral load and genotype were analyzed using an in-house real-time PCR method.

RESULTS

In total, 576 patients were included (417 HIV-1, 104 HIV-2, and 55 HIV-1/2). Ten (1.7%) patients were anti-HCV-positive and eight (1.4%) patients had detectable HCV RNA; all were genotype 2. In a multivariable logistic regression analysis, age >50 years was associated with anti-HCV reactivity (p<0.01). No subjective symptoms or objective signs were more prevalent among patients with detectable HCV RNA compared to patients without detectable HCV RNA. Biochemically, detectable HCV RNA was associated with elevated amylase (83.3% vs. 38.6%, p=0.03), but not with the liver enzymes alanine aminotransferase and aspartate aminotransferase.

CONCLUSIONS

The prevalence of anti-HCV was low and comparable to similar settings, and genotype analysis confirmed the presence of genotype 2 in West Africa.

Cohort Profile: The Bissau HIV Cohort-a cohort of HIV-1, HIV-2 and co-infected patients

The West African country Guinea-Bissau is home to the world's highest prevalence of HIV-2, and its HIV-1 prevalence is rising. Other chronic viral infections like human T-lymphotropic virus type 1 (HTLV-1) and hepatitis B virus are common as well. The Bissau HIV Cohort was started in 2007 to gain new insights into the overall effect of introducing antiretroviral treatment in a treatment-naïve population with concomitant infection with three retroviruses (HIV-1, HIV-2 and HTLV-1) and tuberculosis. The cohort includes patients from the HIV clinic at Hospital Nacional Simão Mendes, the main hospital in Bissau, the capital of the country. From July 2007 to June 2013, 3762 HIV-infected patients (69% HIV-1, 18% HIV-2, 11% HIV-1/2 and 2% HIV type unknown) were included in the world's largest single-centre HIV-2 cohort. Demographic and clinical data are collected at baseline and every 6 months, together with CD4 cell count and routine biochemistry analyses. Plasma and cells are stored in a biobank in Denmark. The Bissau HIV Cohort is administered by the Bissau HIV Cohort study group. Potential collaborators are invited to contact the chair of the cohort study group, Christian Wejse, e-mail: [wejse@dadlnet.dk].

Challenges facing HIV treatment in Guinea-Bissau: the benefits of international research collaborations

PROBLEM

The introduction of antiretroviral therapy (ART) for HIV infection in sub-Saharan Africa has improved the quality of life of millions of people and reduced mortality. However, substantial problems with the infrastructure for ART delivery remain.

APPROACH

Clinicians and researchers at an HIV clinic in Guinea-Bissau identified problems with the delivery of ART by establishing a clinical database and by collaborating with international researchers.

LOCAL SETTING

The Bissau HIV cohort study group was established in 2007 as a collaboration between local HIV physicians and international HIV researchers. Patients were recruited from the HIV clinic at the country's main hospital in the capital Bissau.

RELEVANT CHANGES

Between 2005 and 2013, 5514 HIV-positive patients were treated at the clinic. Working together, local health-care workers and international researchers identified the main problems affecting ART delivery: inadequate drug supply; loss of patients to follow-up; and inadequate laboratory services. Solutions to these problems were devised. The collaborations encouraged local physicians to start their own research projects to find possible solutions to problems at the clinic.

LESSONS LEARNT

The HIV clinic in Bissau faced numerous obstacles in delivering ART at a sufficiently high quality and patients' lives were put in jeopardy. The effectiveness of ART could be enhanced by delivering it as part of an international research collaboration since such collaborations can help identify problems, find solutions and increase the capacity of the health-care system.