Tenofovir for prevention of mother to child transmission of hepatitis B in migrant women in a resource-limited setting on the Thailand-Myanmar border: a commentary on challenges of implementation

Prevention, testing, and treatment interventions for hepatitis B and C in refugee populations: results of a scoping review

BACKGROUND AND AIMS

Refugees are at higher risk for hepatitis B (HBV) and hepatitis C (HCV), but often face unique healthcare barriers to vaccination, testing, and treatment. This scoping review aimed to identify and characterize HBV and HCV prevention and care services serving refugee populations globally.

METHODS

A literature search was conducted on Embase, Cochrane, and PubMed databases. Research studies published in English between January 2010 to July 2022 describing an HBV or HCV prevention, testing, or treatment intervention for refugees were included.

RESULTS

There were a total of 69 articles reporting viral hepatitis prevalence, implementation of services, or economic modelling. Of the 38 implementation studies, 14 were stand-alone HBV and/or HCV interventions, while 24 studies included HBV and/or HCV in an intervention targeting multiple infectious diseases and/or parasitic infections. Interventions commonly included a testing (n = 30) or referral (n = 24) component. Frequently reported features to promote program accessibility included bilingual services (n = 25), community partnerships (n = 21), and multidisciplinary staff members (n = 18), such as cultural and/or linguistic mediators, community health workers, community health leaders, lay health workers, local health staff, members of the refugee community, and social workers. The most commonly reported challenge was the transience of refugees (n = 5). Twenty studies noted funding sources, of which twelve reported governmental funding (not including national health insurance) and eight reported that refugees received national health insurance.

CONCLUSIONS

This is the first scoping review to characterize the types of hepatitis prevention, screening, and treatment interventions serving refugee populations globally. Published experiences of HBV and HCV services for refugee populations remain limited. Additional efforts are needed to disseminate models of hepatitis interventions for refugees to ensure access to care for this key population. To achieve hepatitis elimination globally, best practices must be identified and shared to expand access to hepatitis services for refugee populations.

Antivirals for prevention of hepatitis B virus mother-to-child transmission in human immunodeficiency virus positive pregnant women co-infected with hepatitis B virus

BACKGROUND

Hepatitis B virus (HBV)-human Immunodeficiency virus (HIV) co-infection promotes an aggressive disease course of HBV infection. In the only available non-Cochrane systematic review on antiviral therapy during pregnancy for prevention of mother-to-child transmission of HBV, none of the women studied had HBV-HIV co-infection but were either HBV- or HIV-seropositive. Treatment of HBV alone may develop HIV-strains that are resistant to non-nucleoside reverse transcriptase inhibitors. Accordingly, co-treatment of the HIV infection is recommended.

OBJECTIVES

To evaluate the benefits and harms of tenofovir-based antiviral combination regimens versus placebo, tenofovir alone, or non-tenofovir-based antiviral regimen either alone or in combination with HBV for the prevention of mother-to-child transmission of HBV in HIV-positive pregnant women co-infected with HBV.

SEARCH METHODS

We searched the Cochrane Hepato-Biliary Group Controlled Trials Register, Cochrane Central Register of Controlled Trials, MEDLINE Ovid, Embase Ovid, LILACS (Bireme), Science Citation Index Expanded (Web of Science), and Conference Proceedings Citation Index-Science (Web of Science) on 30 January 2023. We manually searched the reference lists of included trials, searched on-line trial registries, and contacted experts in the field and pharmaceutical companies for any further potential trials.

SELECTION CRITERIA

We aimed to include randomised clinical trials comparing tenofovir-based antiviral combination regimens (anti-HIV regimen with lopinavir-ritonavir therapy, or any other antiviral therapy, and two drugs with activity against HBV, specifically, tenofovir alafenamide (TAF) or tenofovir disoproxil fumarate (TDF), plus lamivudine or emtricitabine) with placebo alone, or tenofovir alone, or non-tenofovir-based antiviral regimen (zidovudine, lamivudine, telbivudine, emtricitabine, entecavir, lopinavir-ritonavir, or any other antiviral therapy) either alone or in combination with at least two other antivirals.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures expected by Cochrane. Primary outcomes included all-cause infant mortality, proportion of infants with serious adverse events, proportion of infants with HBV mother-to-child transmission, all-cause maternal mortality, and proportion of mothers with serious adverse events. Secondary outcomes included proportion of infants with adverse events not considered serious, proportion of mothers with detectable HBV DNA (deoxyribonucleic acid) (before delivery), maternal hepatitis B e antigen (HBeAg) to HBe-antibody seroconversion (before delivery) and maternal adverse events not considered serious. We used RevMan Web to carry out analyses and presented results, where feasible, using a random-effects model and risk ratios (RR) with 95% confidence intervals (CIs). We performed sensitivity analysis. We assessed risk of bias using predefined domains, assessed the certainty of the evidence using GRADE, controlled risk of random errors with Trial Sequential Analysis, and presented outcome results in a summary of findings table.

MAIN RESULTS

Five completed trials were included, of which four trials contributed data to one or more of the outcomes. They included a total of 533 participants randomised to tenofovir-based antiviral combination regimens (196 participants) versus control (337 participants). The control groups received non-tenofovir-based antiviral regimens either as zidovudine alone (three trials) or as a combination of zidovudine, lamivudine and lopinavir-ritonavir (five trials). None of the trials used placebo or tenofovir alone. All trials were at unclear risk of bias. Four trials used intention-to-treat analyses. In the remaining trial, two participants in the intervention group and two in the control group were lost to follow-up. However, the outcomes of these four participants were not described. Tenofovir-based antiviral combination regimen versus control We are very uncertain about the effect of a tenofovir-based antiviral combination regimen versus control on all-cause infant mortality (RR 2.24, 95% CI 0.72 to 6.96; participants = 132; trials = 1; very low-certainty evidence); proportion of infants with serious adverse events (RR 1.76, 95% CI 1.27 to 2.43; participants = 132; trials = 1; very low-certainty evidence), and proportion of mothers with serious adverse events (RR 0.90, 95% CI 0.62 to 1.32; participants = 262; trials = 2; very low-certainty evidence). No trial reported data on the proportion of infants with HBV mother-to-child transmission and all-cause maternal mortality. We are also very uncertain about the effect of tenofovir-based antiviral combination regimens versus control on the proportion of infants with adverse events not considered serious (RR 0.94, 95% CI 0.06 to 13.68; participants = 31; trials = 1; very low-certainty evidence), and proportion of mothers with detectable HBV DNA (before delivery) (RR 0.66, 95% CI 0.42 to 1.02; participants = 169; trials = 2; very low-certainty evidence). No trial reported data on maternal hepatitis B e antigen (HBeAg) to HBe-antibody seroconversion (before delivery) and maternal adverse events not considered serious. All trials received support from industry.

AUTHORS' CONCLUSIONS

We do not know what the effects of tenofovir-based antiviral combination regimens are on all-cause infant mortality, proportion of infants with serious adverse events and proportion of mothers with serious adverse events, proportion of infants with adverse events not considered serious, and proportion of mothers with detectable HBV DNA before delivery because the certainty of evidence was very low. Only one or two trials, with insufficient power, contributed data for analyses. We lack randomised clinical trials at low risk of systematic and random errors, and fully reporting all-cause infant mortality, serious adverse events and reporting on clinical and laboratory outcomes, such as infants with HBV mother-to-child transmission, all-cause maternal mortality, maternal hepatitis B e antigen (HBeAg) to HBe-antibody seroconversion before delivery and maternal adverse events not considered serious.

Prevalence of hepatitis B virus amongst refugees, asylum seekers and internally displaced persons in low- and middle-income countries: A systematic review

Hepatitis B, caused by the hepatitis B virus (HBV), is a global public health issue that affects 290 million people worldwide. Most people with hepatitis B are in low- and middle-income countries (LMIC), where health systems and resources are often constrained. Refugees, asylum seekers and internally displaced persons (IDPs) often face barriers in seeking health care and are a priority population at risk of hepatitis B. No systematic review to date has evaluated the prevalence of hepatitis B amongst refugees in in LMIC. We undertook a systematic review of the literature identifying 28 studies addressing this topic. Though few studies on this topic exist, the available evidence suggests a high prevalence amongst refugees in LMIC, with wide variation between and within countries. Possible risk factors contributing to hepatitis B include unsafe injections, low immunization coverage, low awareness, mother-to-child transmission, and limited health services. Further study is needed to better understand the prevalence and risk factors for hepatitis B amongst refugees in LMIC, to inform public health responses. Vulnerable populations such as refugees are an important group to consider in national and global efforts to eliminate hepatitis B.