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Concept: Hepadnaviridae

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BACKGROUND: There is agreement that the infectivity assay with the duck hepatitis B virus (DHBV) is a suitable surrogate test to validate disinfectants for hepatitis B virucidal activity. However, since this test is not widely used, information is necessary whether disinfectants with limited virucidal activity also inactivate DHBV. In general, disinfectants with limited virucidal activity are used for skin and sensitive surfaces while agents with full activity are more aggressive. The present study compares the activity of five different biocides against DHBV and the classical test virus for limited virucidal activity, the vaccinia virus strain Lister Elstree (VACV) or the modified vaccinia Ankara strain (MVA). METHODS: Virucidal assay was performed as suspension test according to the German DVV/RKI guideline. Duck hepatitis B virus obtained from congenitally infected Peking ducks was propagated in primary duck embryonic hepatocytes and was detected by indirect immunofluorescent antigen staining. RESULTS: The DHBV was inactivated by the use of 40% ethanol within 1-min and 30% isopropanol within 2-min exposure. In comparison, 40% ethanol within 2-min and 40% isopropanol within 1-min exposure were effective against VACV/MVA. These alcohols only have limited virucidal activity, while the following agents have full activity. 0.01% peracetic acid inactivated DHBV within 2 min and a concentration of 0.005% had virucidal efficacy against VACV/MVA within 1 min. After 2-min exposure, 0.05% glutardialdehyde showed a comparable activity against DHBV and VACV/MVA. This is also the case for 0.7% formaldehyde after a contact time of 30 min. CONCLUSIONS: Duck hepatitis B virus is at least as sensitive to limited virucidal activity as VACV/MVA. Peracetic acid is less effective against DHBV, while the alcohols are less effective against VACV/MVA. It can be expected that in absence of more direct tests the results may be extrapolated to HBV.

Concepts: Alcohol, Virus, Ethanol, Hepatitis B, Viruses, Vaccinia, Hepadnaviridae, Modified vaccinia Ankara

27

Defining mechanisms of direct-acting antivirals facilitates drug development and our understanding of virus function. Heteroaryldihydropyrimidines (HAPs) inappropriately activate assembly of hepatitis B virus (HBV) core protein (Cp), suppressing formation of virions. We examined a fluorophore-labeled HAP, HAP-TAMRA. HAP-TAMRA induced Cp assembly and also bound pre-assembled capsids. Kinetic and spectroscopic studies imply that HAP-binding sites are usually not available but are bound cooperatively. Using cryo-EM, we observed that HAP-TAMRA asymmetrically deformed capsids, creating a heterogeneous array of sharp angles, flat regions, and outright breaks. To achieve high resolution reconstruction (<4 Å), we introduced a disulfide crosslink that rescued particle symmetry. We deduced that HAP-TAMRA caused quasi-sixfold vertices to become flatter and fivefold more angular. This transition led to asymmetric faceting. That a disordered crosslink could rescue symmetry implies that capsids have tensegrity properties. Capsid distortion and disruption is a new mechanism by which molecules like the HAPs can block HBV infection.

Concepts: Virus, Cirrhosis, Hepatitis, Antiviral drug, Hepatitis B, Viruses, Hepatitis B virus, Hepadnaviridae

26

Hepatitis B virus (HBV) reactivation after chemotherapy regimens is a well-known complication. The incidence and risk factors for HBV reactivation remain to be elucidated. We aimed to determine the incidence and risk factors for HBV reactivation in patients receiving rituximab, and the potential role of the cumulative rituximab dose in HBV reactivation. We retrospectively reviewed 320 patients receiving rituximab in our hospital. Of these, 42 (13.12%) had serological markers of hepatitis B. During follow-up, 21% (9/42) had HBV reactivation. Risk factors for reactivation were HBsAg positivity (p<0.05), isolated anti-HBc positivity (p<0.05), marginal zone lymphoma, and Mantle cell lymphoma (p<0.05). The median rituximab dose tended to be higher in patients with reactivation (p=0.06).

Concepts: Chemotherapy, Cirrhosis, Hepatitis, Hepatitis B, Chemotherapy regimens, Hepatitis B virus, Hepadnaviridae, Mantle cell lymphoma

21

Previous studies have demonstrated that nucleic acid polymers (NAPs) have both entry and post-entry inhibitory activity against duck hepatitis B virus (DHBV) infection. The inhibitory activity exhibited by NAPs prevented DHBV infection of primary duck hepatocytes in vitro and protected ducks from DHBV infection in vivo and did not result from direct activation of the immune response. In the current study treatment of primary human hepatocytes with NAP REP 2055 did not induce expression of the TNF, IL6, IL10, IFNA4 or IFNB1 genes, confirming the lack of direct immunostimulation by REP 2055. Ducks with persistent DHBV infection were treated with NAP 2055 to determine if the post-entry inhibitory activity exhibited by NAPs could provide a therapeutic effect against established DHBV infection in vivo. In all REP 2055-treated ducks, 28 days of treatment lead to initial rapid reductions in serum DHBsAg and DHBV DNA and increases in anti-DHBs antibodies. After treatment, 6/11 ducks experienced a sustained virologic response: DHBsAg and DHBV DNA remained at low or undetectable levels in the serum and no DHBsAg or DHBV core antigen positive hepatocytes and only trace amounts of DHBV total and covalently closed circular DNA (cccDNA) were detected in the liver at 9 or 16 weeks of follow-up. In the remaining 5/11 REP 2055-treated ducks, all markers of DHBV infection rapidly rebounded after treatment withdrawal: At 9 and 16 weeks of follow-up, levels of DHBsAg and DHBcAg and DHBV total and cccDNA in the liver had rebounded and matched levels observed in the control ducks treated with normal saline which remained persistently infected with DHBV. These data demonstrate that treatment with the NAP REP 2055 can lead to sustained control of persistent DHBV infection. These effects may be related to the unique ability of REP 2055 to block release of DHBsAg from infected hepatocytes.

Concepts: Immune system, DNA, Bacteria, Virus, Cirrhosis, Hepatitis, Hepatitis B, Hepadnaviridae

13

All known hepatitis B virus (HBV) genotypes occur in humans and hominoid Old World nonhuman primates (NHP). The divergent Woolly Monkey HBV (WMHBV) forms another orthohepadnavirus species. The evolutionary origins of HBV are unclear.

Concepts: Evolution, Virus, Hepatitis B, Primate, Ape, Hepatitis B virus, Hepadnaviridae, Monkey

10

To tackle the high prevalence of Hepatitis B virus (HBV) infection in North Korea, it is essential that birth doses of HBV vaccines should be administered within 24 hours of birth. As the country fails to provide a Timely Birth Dose (TBD) of HBV vaccine, the efforts of reducing the high prevalence of HBV have been significantly hampered.

Concepts: Immune system, Vaccination, Cirrhosis, Hepatitis, Hepatitis B, Hepatitis B virus, Hepadnaviridae, Hepatitis B vaccine

6

Poor adherence to treatment diminishes its individual and public health benefit. Financial incentives, provided on the condition of treatment attendance, could address this problem. Injecting drug users are a high-risk group for hepatitis B virus (HBV) infection and transmission, but adherence to vaccination programmes is poor. We aimed to assess whether contingency management delivered in routine clinical practice increased the completion of HBV vaccination in individuals receiving opioid substitution therapy.

Concepts: Cirrhosis, Hepatitis, Hepatitis B, Morphine, Drug addiction, Heroin, Hepatitis B virus, Hepadnaviridae

5

This study aimed to evaluate the effect of a lay health worker (LHW) telephone intervention on completing a series of hepatitis B virus (HBV) vaccinations among foreign-born Asian Americans in the Baltimore-Washington Metropolitan area.

Concepts: Randomized controlled trial, Cirrhosis, Hepatitis, Hepatitis B, Viruses, Hepatitis B virus, Hepadnaviridae, Hepatitis B vaccine

4

Vaccination, screening, and linkage to care can reduce the burden of chronic hepatitis B virus (HBV) infection. However, recommendations vary among organizations, and their implementation has been suboptimal. The American College of Physicians' High Value Care Task Force and the Centers for Disease Control and Prevention developed this article to present best practice statements for hepatitis B vaccination, screening, and linkage to care.

Concepts: Cirrhosis, Hepatitis, Hepatitis B, Viruses, Hepatitis A, Hepatitis B virus, Hepadnaviridae, Hepatitis B vaccine

4

Rheumatoid arthritis (RA) with concomitant hepatitis B virus (HBV) infection represents a therapeutic challenge due to the risk of HBV reactivation under immunosuppressive treatment. To date there are few data concerning the HBV reactivation following treatment with abatacept coming from anecdotal case reports. This observational retrospective study was aimed to assess the safety profile of abatacept in this particular clinical setting.

Concepts: Cirrhosis, Hepatitis, Rheumatoid arthritis, Rheumatology, Hepatitis B, Hepatitis B virus, Hepadnaviridae, Anecdotal evidence