Molecular characterisation of hepatitis A in the Western Cape province, South Africa in 2023.

In 2023, passive laboratory-based surveillance showed an increase in hepatitis A virus (HAV) infection. We investigated hepatitis A incidence using the notifiable medical condition surveillance system (NMCSS) data and molecularly characterised positive blood samples from the Western Cape province for 2023. All HAV IgM seropositive cases from the NMCSS from 1 January to 31 October 2023 in South Africa were investigated. HAV RNA from blood samples that had tested positive for HAV IgM from Western Cape was amplified in the VP1/P2B junction and sequenced (3500Xl Genetic Analyser). Sequences were assembled, aligned (Sequencher) and analysed (Aliview 1.27 and MEGA11). Statistical analysis was performed using Excel and the CuSum2 Threshold to determine suspected outbreaks. In 2023, the incidence of HAV IgM was 6.28/100,000 in South Africa, with the highest incidence in Western Cape province (15.86/100,000). Children aged 5 to 14 years were affected the most in the Western Cape. The positive cases in the Western Cape were above the CuSum2 threshold from January to May 2023, with the highest incidence observed in the City of Cape Town Metropolitan (14.8/100,000). Genotyping was successfully performed on 92.7% (139/150) of serum samples, for which the IB sub-genotype was detected. Three primary mutations R63K, R71S and M104I were observed in more than 49% of the samples. Most of the samples sequenced belonged to patients residing in areas close to each other within the City of Cape Town Southern, Western, and Mitchells Plain sub-districts. The CuSum2 threshold method allowed the identification of suspected HAV outbreaks in the districts within the Western Cape in 2023 while genotyping identified clusters of sub-genotype IB. Genotyping could assist with determining the common source of infection during an outbreak, especially if coupled with epidemiological and geographical data. Further active surveillance can assist in investigating the HAV risk factors for targeted public health responses.

Presence of Enteric Viruses in Shellfish Samples from the Persian Gulf.

Shellfishes are a significant economic and nutritious seafood amongst people in different countries. Seafood products, particularly shellfish, are potential reservoirs of enteric viruses. This research investigated the incidence of rotavirus (RoV), norovirus (NoV) GI and GII, hepatitis A virus (HAV), and hepatitis E virus (HEV) in shellfish samples from the Persian Gulf, Iran. One hundred and fifty shellfish samples were collected. RNA extraction and cDNA synthesis were performed using commercial kits. The real-time polymerase chain reaction assessed the presence of enteric viruses in extracted cDNA samples. Thirty-two out of 150 (21.33%) shellfish samples were contaminated with enteric viruses. Prevalence rates of NoV GI, NoV GII, HAV, and RoV amongst shellfish samples were 8.00%, 11.33%, 1.33%, and 0.66%, respectively. There were no contaminated shellfish samples with HEV. Simultaneous prevalence of HAV and NoV GI, and HAV and NoV GII viruses were 0.66% and 0.66%, respectively. Examined viruses had a higher prevalence in shellfish samples collected in the winter season (P<0.05). Prevalence of HAV, RoV, NoV GI, and NoV GII amongst shellfish samples gathered in the winter season was 2.85%, 9.09%, 11.90%, and 20%, respectively. To the best of our knowledge, this was the first report of the incidence of enteric viruses, particularly HAV, NoV GI, NoV GII, and RoV, in shellfish samples from the Persian Gulf, Iran. Shellfish samples may serve as a potential source of enteric viruses for the human population. Therefore, routine viral assessments should be conducted. The consumption of fully cooked shellfish can significantly reduce the risk of HAV, RoV, NoV GI, and NoV GII infections. Furthermore, given the export value and importance of shellfish samples, their microbial quality and safety should be routinely monitored.

Inactivation of murine norovirus and hepatitis A virus on various frozen fruits using pulsed light.

The frozen fruit sector has experienced significant growth due to improved product quality as well as the advantage of long-term preservation. However, freezing alone does not eliminate foodborne viruses, a major public health concern and considerable economic burden. One promising disinfecting treatment is pulsed light, shown previously to inactivate hepatitis A virus (HAV) and murine norovirus-1 (MNV-1) on the surface of fresh berries. Viral loads were reduced by 1-2 log, with minor visual quality deterioration observed. In this study, an FDA-compliant pulsed light treatment (11.52 J/cm2) was applied to frozen fruits and berries. Infectious MNV-1 and HAV titers were reduced by 1-2 log on most frozen fruits. A noteworthy finding was that reductions of both viruses on cranberries exceeded 3.5 log cycles. Although pulsed light caused a measurable rise in temperature on the product surface, no visible physical changes (e.g., color) were observed, and the fruit pieces were still frozen after treatment. Although the reduction of infectious titer by pulsed light alone was not large (1-2 log), considering the low amount of virus typically found on fruit, it may be beneficial in the frozen fruit sector. It would be easy to combine with other treatments, and synergic interactions might increase virus inactivation.

Hepatitis A in Latin America: The current scenario.

This review aims to gather and disseminate updated information regarding hepatitis A virus (HAV) in Latin America (LA) in the last 11 years, including seroprevalence, post-vaccination studies, virus detection in aqueous matrices and food samples, and outbreak reports. Only 24 seroprevalence studies were published between 2012 and 2023 with 55%-100% reported prevalences of anti-HAV IgG. Among the 25 LA countries, only eight of them have introduced HAV vaccines into their immunisation programs. Outbreaks of hepatitis A occurred between 2017-2019, mainly affecting men who have sex with men in Argentina, Brazil and Chile, probably as a consequence of the abrupt decline of young adults' immunity. This could be due to that young adult have never been infected in childhood (due to socio-health improvements) and are above the cut-off ages to be included when the vaccination programs were introduced. Although scarce, studies focused on environmental and food HAV surveillance have shown viral presence in these samples. Surface waters presented HAV detections between 1.2% and 86.7%, and untreated wastewaters between 2.8% and 70.9%. Genotypes found in all cases were IA and IC. The only wastewater-based epidemiology study showed to be a useful tool as a complement of traditional epidemiological surveillance. Only four LA countries have looked for HAV in food samples, with genome detection rates between 9% and 33%. Latin American HAV circulation scenario is changing. In countries where socioeconomic and sanitary conditions have not improved, the virus persists with high endemicity and the access to the vaccine should be re-evaluated by local governments. In countries where access to clean water, better sanitary conditions and HAV immunisation programs have been implemented, the number of cases among young adults seems to be increasing, alerting health authorities.

Prevalence of hepatitis A virus among migrant workers in Qatar: A national study.

BACKGROUND: Hepatitis A virus (HAV) is the predominant cause of acute viral hepatitis worldwide; however, data on HAV antibody prevalence (seroprevalence) among migrant populations are limited. This study aimed to investigate HAV seroprevalence among Qatar's migrant craft and manual workers (CMWs), constituting approximately 60% of the country's population. METHODS: HAV antibody testing was conducted on stored serum specimens obtained from CMWs during a nationwide severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) population-based cross-sectional survey between July 26 and September 9, 2020. Associations with HAV infection were investigated through regression analyses. RESULTS: Of the 2,607 specimens with HAV antibody test results, 2,393 were positive, and 214 were negative. The estimated HAV seroprevalence among CMWs was 92.0% (95% CI: 90.9-93.1%). HAV seroprevalence was generally high but exhibited some variation, ranging from 70.9% (95% CI: 62.4-78.2%) among Sri Lankans to 99.8% (95% CI: 98.2-99.9%) among Pakistanis. The multivariable regression analysis identified age, nationality, and educational attainment as statistically significant factors associated with HAV infection. Relative to CMWs aged ≤29 years, the adjusted relative risk (ARR) was 1.06 (95% CI: 1.03-1.10) in CMWs aged 30-39 years and reached 1.15 (95% CI: 1.10-1.19) in those aged ≥50 years. In comparison to Indians, the ARR was lower among Sri Lankans, assessed at 0.81 (95% CI: 0.72-0.91), but higher among Nepalese at 1.07 (95% CI: 1.04-1.11), Bangladeshis at 1.10 (95% CI: 1.07-1.13), Pakistanis at 1.12 (95% CI: 1.09-1.15), and Egyptians at 1.15 (95% CI: 1.08-1.23). No evidence for differences was found by geographic location or occupation. CONCLUSIONS: HAV seroprevalence among Qatar's CMW population is very high, with over nine out of every ten individuals having been exposed to this infection, likely during childhood.

Indicator and pathogenic virus removal in bench scale soil aquifer treatment.

The demonstration of enteric virus removal for indirect potable reuse of advanced purified water is necessary to ensure safe water reclamation practices. This study evaluated the efficacy of soil treatment in reducing concentrations of Pepper Mild Mottle Virus (PMMoV), Hepatitis A (HAV), and Norovirus (NoV) gene markers through bench scale unsaturated soil columns. Three different infiltration rates were evaluated to determine their impact on viral gene marker removal. The concentrations of viral markers in the column influent and effluent samples were measured through RNA extraction and then RT-qPCR, and the log reduction values (LRVs) were calculated to quantify the effectiveness of removal across the columns. The LRVs achieved for PMMoV were 2.80 ± 0.36, 2.91 ± 0.48, and 2.72 ± 0.32 for infiltration rates of 4.9 mm/h, 9.4 mm/h, and 14.0 mm/h, respectively. A one-way ANOVA indicated no statistically significant differences in LRVs among the various infiltration rates (p-value = 0.329). All samples measured for HAV were below the detection limit both in the influent and effluent of the soil columns. While NoV GI and GII markers were measurable in the soil column influent, they were removed to below the detection limit in the effluent. The use of half the Limit-of-Detection (LoD) for effluent values enabled the estimation of log removals, which were calculated as 1.42 ± 0.07, 1.64 ± 0.29, and 1.74 ± 0.18 for NoV GI and 1.14 ± 0.19, 1.58 ± 0.21, and 1.87 ± 0.41 for NoV GII at infiltration rates of 4.9 mm/h, 9.4 mm/h, and 14.0 mm/h. This highlights the efficacy of soil treatment in reducing virus gene marker concentrations at various infiltration rates, and that spreading basins employed for reclaimed water recharge to ground water aquifers are an effective method for reducing the presence of viral contaminants in indirect potable reuse systems.

Rising trend of symptomatic infections due to Hepatitis A virus infection in adolescent and adult age group: An observational study from a tertiary care liver institute in India.

BACKGROUND: Hepatitis A Virus (HAV) is the most common cause of Acute Viral Hepatitis (AVH) in children. It causes self-limiting illness and rarely acute liver failure. The shifting pattern in HAV endemicity is rendering adolescents and adults vulnerable to infection. METHODS: In this retrospective study, samples received from 14,807 patients with acute onset icteric illness from January 2014-December 2022 were analyzed. HAV infection was detected by anti-HAV IgM positivity. The cases were divided into 3 age groups, pediatric, adolescents and adults, and clinical presentations were compared. RESULTS: Overall, 7.72%(1144) were positive for anti-HAV IgM. Of these, 60%(690) were finally included in the study. The positive cases were divided into adults, ≥18 years (44%, 304); pediatric, <12 years (31%, 212) and adolescents (25%,174) age groups. Overall males were predominant [72.4%(500)], with a median age of 16 (IQR:9-21) years. Cases were characterised into AVH (68.1%, 470/690), Acute Liver Failure (ALF) (31.4%, 217/690) and Acute-on-Chronic Liver Failure (0.43%, 3/690). AVH in the pediatric age group was 69%(146/212), adolescents was 67%(117/174), and adults was 68%(207/304). ALF cases among the 3 groups were 30%(65/212), 33%(57/174), and 31%(95/304) respectively. Overall mortality was seen in 6.52%(45/690), maximum in adolescents with ALF presentation [10.3%(18/174)]. On molecular characterization of infection, viremia was seen in 28.9%(200/690) and all the isolates were Genotype IIIA. CONCLUSIONS: The number of adults experiencing symptomatic HAV infection was seen to increase over the years in the present study. Infection in adolescents was associated with higher mortality and ALF as the clinical presentation.

Ongoing outbreak of hepatitis A associated with sexual transmission among men who have sex with men, Portugal, October 2023 to April 2024.

An outbreak of hepatitis A is ongoing in Portugal, with 71 confirmed cases from 7 October 2023 to 24 April 2024. Most cases are male, aged 18-44 years, with many identifying as men who have sex with men (MSM) and reported as suspected sexual transmission. Phylogenetic analysis identified the subgenotype IA, VRD 521-2016 strain, last observed in an MSM-associated multi-country outbreak in 2016 to 2018. We wish to alert colleagues in other countries to investigate potential similar spread.

A Reliable Multifaceted Solution against Foodborne Viral Infections: The Case of RiLK1 Decapeptide.

Food-borne transmission is a recognized route for many viruses associated with gastrointestinal, hepatic, or neurological diseases. Therefore, it is essential to identify new bioactive compounds with broad-spectrum antiviral activity to exploit innovative solutions against these hazards. Recently, antimicrobial peptides (AMPs) have been recognized as promising antiviral agents. Indeed, while the antibacterial and antifungal effects of these molecules have been widely reported, their use as potential antiviral agents has not yet been fully investigated. Herein, the antiviral activity of previously identified or newly designed AMPs was evaluated against the non-enveloped RNA viruses, hepatitis A virus (HAV) and murine norovirus (MNV), a surrogate for human norovirus. Moreover, specific assays were performed to recognize at which stage of the viral infection cycle the peptides could function. The results showed that almost all peptides displayed virucidal effects, with about 90% of infectivity reduction in HAV or MNV. However, the decapeptide RiLK1 demonstrated, together with its antibacterial and antifungal properties, a notable reduction in viral infection for both HAV and MNV, possibly through direct interaction with viral particles causing their damage or hindering the recognition of cellular receptors. Hence, RiLK1 could represent a versatile antimicrobial agent effective against various foodborne pathogens including viruses, bacteria, and fungi.

Whole-Genome Sequencing-Based Confirmatory Methods on RT-qPCR Results for the Detection of Foodborne Viruses in Frozen Berries.

Accurate detection, identification, and subsequent confirmation of pathogens causing foodborne illness are essential for the prevention and investigation of foodborne outbreaks. This is particularly true when the causative agent is an enteric virus that has a very low infectious dose and is likely to be present at or near the limit of detection. In this study, whole-genome sequencing (WGS) was combined with either of two non-targeted pre-amplification methods (SPIA and SISPA) to investigate their utility as a confirmatory method for RT-qPCR positive results of foods contaminated with enteric viruses. Frozen berries (raspberries, strawberries, and blackberries) were chosen as the food matrix of interest due to their association with numerous outbreaks of foodborne illness. The hepatitis A virus (HAV) and human norovirus (HuNoV) were used as the contaminating agents. The non-targeted WGS strategy employed in this study could detect and confirm HuNoV and HAV at genomic copy numbers in the single digit range, and in a few cases, identified viruses present in samples that had been found negative by RT-qPCR analyses. However, some RT-qPCR-positive samples could not be confirmed using the WGS method, and in cases with very high Ct values, only a few viral reads and short sequences were recovered from the samples. WGS techniques show great potential for confirmation and identification of virally contaminated food items. The approaches described here should be further optimized for routine application to confirm the viral contamination in berries.

Loxapine inhibits replication of hepatitis A virus in vitro and in vivo by targeting viral protein 2C.

No antiviral drugs currently are available for treatment of infection by hepatitis A virus (HAV), a causative agent of acute hepatitis, a potentially life-threatening disease. Chemical screening of a small-compound library using nanoluciferase-expressing HAV identified loxapine succinate, a selective dopamine receptor D2 antagonist, as a potent inhibitor of HAV propagation in vitro. Loxapine succinate did not inhibit viral entry nor internal ribosome entry site (IRES)-dependent translation, but exhibited strong inhibition of viral RNA replication. Blind passage of HAV in the presence of loxapine succinate resulted in the accumulation of viruses containing mutations in the 2C-encoding region, which contributed to resistance to loxapine succinate. Analysis of molecular dynamics simulations of the interaction between 2C and loxapine suggested that loxapine binds to the N-terminal region of 2C, and that resistant mutations impede these interactions. We further demonstrated that administration of loxapine succinate to HAV-infected Ifnar1-/- mice (which lack the type I interferon receptor) results in decreases in the levels of fecal HAV RNA and of intrahepatic HAV RNA at an early stage of infection. These findings suggest that HAV protein 2C is a potential target for antivirals, and provide novel insights into the development of drugs for the treatment of hepatitis A.

Assessing Immunity to Hepatitis A and Hepatitis B Among Individuals in Custody Living With HIV.

Screening upon entry into prison for hepatitis A virus (HAV) and hepatitis B virus (HBV) provides an ideal public health opportunity to offer vaccination to individuals who are nonimmune. We conducted a retrospective review of HAV and HBV immunity among adults living with HIV in the Illinois Department of Corrections between January 1, 2019, and December 31, 2019. The primary objective was to assess rates of HAV and/or HBV immunity in individuals with HIV. In total, 436 people were included in the study. Of 425 patients who had data for HAV vaccination, 335 were immune. Of 421 patients who had data for HBV vaccination, 272 were immune. Of the 149 patients who were nonimmune to HBV, 22 had active HBV and 6 had an equivocal HBV surface antibody and negative HBV surface antigen. In total, 212 (52%) were immune to both HAV and HBV, and 31 (8%) had no immunity to either HAV or HBV. These data demonstrate an important opportunity to discuss and provide vaccination while in custody.

Evaluation of a new automated viral RNA extraction platform for hepatitis A virus and human norovirus in testing of berries, lettuce, and oysters.

Fruits, vegetables, and shellfish are often associated with outbreaks of illness caused particularly by human norovirus (HuNoV) and hepatitis A virus (HAV), the leading causative agents of foodborne illness worldwide. The aim of this study was to evaluate a new automated nucleic acid extraction platform (EGENE-UP EASYPREP) for enteric viruses in several at-risk food matrices and to test its limit of detection in comparison to a semi-automated method (EGENE-UP) using Boom methodology for nucleic acid extraction as suggested in the reference method ISO 15216-2:2019. Fresh and frozen raspberries, frozen blackberries, romaine lettuce and oyster digestive glands were artificially contaminated with HAV, HuNoV GII.4 or HuNoV GI.7 at 102, 103 or 104 genome copies/sample. Virus was then recovered from the food matrix using the ISO method. Viral RNA extracted from frozen berry samples by the automated system was purified on a column for additional removal of RT-qPCR inhibitors. For fresh raspberry, oysters, and romaine lettuce, the two extraction platforms were deemed equivalent. For frozen raspberry, the automated platform appeared to be more efficient for viral recovery, particularly for HAV and HuNoV GI at lower concentrations. With frozen blackberries, the two platforms may be considered equivalent for all targeted viruses. However, the automated method led to less sample-associated inhibition of the PCR, 56.5 % of samples versus 95.0 % for the semi-automated. We thus found that the automated extraction can be performed easily by users while obtaining equivalent or even superior results to the ISO 15216-2:2019 method, and therefore appears to be suitable for routine sanitary monitoring in food processing and for tracing outbreaks of illness.

Concentration of foodborne viruses eluted from fresh and frozen produce: Applicability of ultrafiltration.

Foodborne illnesses involving raw and minimally processed foods are often caused by human noroviruses (HuNoV) and hepatitis A virus (HAV). Since food is contaminated usually with small numbers of virions, these must be eluted from the food surface and then concentrated for detection. The objective of this study was to optimize an ultrafiltration (UF) concentration method for HAV and HuNoVs present on various fresh and frozen produce. The detection range of the optimized method and its applicability to different food matrices was compared to the reference method ISO 15216-1:2017. Strawberry, raspberry, blackberry, lettuce, and green onion (25 g) were contaminated with HAV, HuNoV GI.7 and HuNoV GII.4 and then recovered therefrom by elution. A commercial benchtop UF device was used for the concentration step. Viral RNA was extracted and detected by RT-qPCR. From fresh strawberries, recovery of HAV loaded at 104 genome copies per sample was 30 ± 13 %, elution time had no significant impact, and UF membrane with an 80-100 kDa cut-off in combination with Tris-glycine elution buffer at pH 9.5 was found optimal. At lower copy numbers on fresh strawberry, at least 1 log lower numbers of HuNoV were detectable by the UF method (103 vs 104 GII.4 copies/sample and 101 vs 103 GI.7 copies/sample), while HAV was detected at 101 genome copies/sample by both methods. Except on raspberry, the UF method was usually equivalent to the ISO method regardless of the virus tested. The UF method makes rapid viral concentration possible, while supporting the filtration of large volume of sample. With fewer steps and shorter analysis time than the ISO method, this method could be suitable for routine analysis of viruses throughout the food production and surveillance chain.

Factors associated with hepatitis A susceptibility among men who have sex with men using HIV pre-exposure prophylaxis in Northeastern Brazil: A cross-sectional study.

Hepatitis A virus (HAV) infection has disproportionately affected more men who have sex with men (MSM), occurring in outbreaks, despite being vaccine-preventable. We determined the prevalence and factors associated with HAV susceptibility among cisgender MSM on HIV pre-exposure prophylaxis (PrEP) in Northeastern Brazil. From September 30, 2021 to June 19, 2023, 282 cisgender MSM receiving HIV PrEP were enrolled into this cross-sectional study. Sociodemographic and clinical information were collected. Blood samples were collected for screening of sexually transmitted infections (STIs) and serum samples were tested for IgM and total anti-HAV antibodies. Non-reactive results for total anti-HAV antibodies were found in 106 of 282 (37.6%) participants. Factors associated with HAV susceptibility included age <30 years (prevalence ratio [PR]: 2.02; 95% confidence interval [95% CI]: 1.61-2.53), having health insurance (PR: 1.39; 95% CI: 1.19-1.64), sex only with cisgender men (PR: 1.52; 95% CI: 1.23-1.89), non-steady partner (PR: 1.20; 95% CI: 1.01-1.43) and no lifetime history of STIs (PR: 1.25; 95% CI: 1.03-1.53). Identifying clinical correlates of HAV susceptibility in key populations is a fundamental step towards development of public policy focused on prevention, especially following the recent hepatitis A outbreak in Brazil.

Biochemical analysis of the host factor activity of ZCCHC14 in hepatitis A virus replication.

Relatively little is known of the mechanisms underlying hepatitis A virus (HAV) genome replication. Unlike other well-studied picornaviruses, HAV RNA replication requires the zinc finger protein ZCCHC14 and non-canonical TENT4 poly(A) polymerases with which it forms a complex. The ZCCHC14-TENT4 complex binds to a stem-loop located within the internal ribosome entry site (IRES) in the 5' untranslated RNA (5'UTR) and is essential for viral RNA synthesis, but the underlying mechanism is unknown. Here, we describe how different ZCCHC14 domains contribute to its RNA-binding, TENT4-binding, and HAV host factor activities. We show that the RNA-binding activity of ZCCHC14 requires both a sterile alpha motif (SAM) and a downstream unstructured domain (D4) and that ZCCHC14 contains two TENT4-binding sites: one at the N-terminus and the other around D4. Both RNA-binding and TENT4-binding are required for HAV host factor activity of ZCCHC14. We also demonstrate that the location of the ZCCHC14-binding site within the 5'UTR is critical for its function. Our study provides a novel insight into the function of ZCCHC14 and helps elucidate the mechanism of the ZCCHC14-TENT4 complex in HAV replication.IMPORTANCEThe zinc finger protein ZCCHC14 is an essential host factor for both hepatitis A virus (HAV) and hepatitis B virus (HBV). It recruits the non-canonical TENT4 poly(A) polymerases to viral RNAs and most likely also a subset of cellular mRNAs. Little is known about the details of these interactions. We show here the functional domains of ZCCHC14 that are involved in binding to HAV RNA and interactions with TENT4 and describe previously unrecognized peptide sequences that are critical for the HAV host factor activity of ZCCHC14. Our study advances the understanding of the ZCCHC14-TENT4 complex and how it functions in regulating viral and cellular RNAs.

"PROTAC" modified dihydroquinolizinones (DHQs) that cause degradation of PAPD-5 and inhibition of hepatitis A virus and hepatitis B virus, in vitro.

Dihydroquinolizinones (DHQs) that inhibit cellular polyadenylating polymerases 5 and 7 (PAPD5 & 7), such as RG7834, have been shown to inhibit both hepatitis A (HAV) and hepatitis B virus (HBV) in vitro and in vivo. In this report, we describe RG7834-based proteolysis-targeting chimeras (PROTACs), such as compound 12b, (6S)-9-((1-((2-(2,6-dioxopiperidin-3-yl)-1,3-dioxoisoindolin-4-yl)amino)-21-oxo-3,6,9,12,15,18-hexaoxa-22-azapentacosan-25-yl)oxy)-6-isopropyl-10-methoxy-2-oxo-6,7-dihydro-2H-pyrido[2,1-a]isoquinoline-3-carboxylic acid. The PROTAC DHQs described here inhibited an HAV reporter virus in vitro with an IC50 of 277 nM. Although the PROTAC DHQs were also inhibitory to HBV, their activities were substantially less potent against HBV in vitro, being in the 10 to 20 µM range, based on the reduction of HBsAg and HBV mRNA levels. Importantly, unlike RG7834, the incubation of cells in vitro with PROTAC DHQ 12b resulted in the degradation of PAPD5, as expected for a PROTAC compound, but curiously not PAPD7. PAPD5 polypeptide degradation was prevented when a proteasome inhibitor, epoxomicin, was used, indicating that proteasome mediated proteolysis was associated with the observed activities of 12b. Taken together, these data show that 12b is the first example of a PROTAC that suppresses both HAV and HBV that is based on a small molecule warhead. The possibility that it has mechanisms that differ from its parent compound, RG7834, and has clinical value, is discussed.

Hepatitis A Virus Infection in Cynomolgus Monkeys Confounds the Safety Evaluation of a Drug Candidate.

In a 3-month toxicity study in cynomolgus monkeys at a European contract laboratory, animals were infected with HAV, initially resulting in hepatic injury being incorrectly attributed to the test compound. Elevated serum ALT/AST/GLDH (5- to 10-fold) were noted in individual animals from all groups including controls, with no apparent dose, exposure, or time-related relationship. Liver histopathology revealed minimal to slight inflammatory cell accumulation in periportal zones of most animals, and minimal to slight hepatocyte degeneration/necrosis in 10/42 animals from all groups. As these findings were more pronounced in 6 drug-treated animals, including 2/6 in the low dose group, the draft report concluded: "treatment-related hepatotoxicity at all dose levels precluded determination of a NOAEL." However, the unusual pattern of hepatotoxicity suggested a factor other than drug exposure might have caused the hepatic effects. Therefore, snap-frozen liver samples were tested for hepatitis viruses using a PCR method. Tests for hepatitis B, C, and E virus were negative; however, 20/42 samples were positive for hepatitis A virus (HAV). Infection was strongly associated with increased serum ALT/GLDH, and/or hepatocyte degeneration/necrosis. Re-evaluation of the study in light of these data concluded that the hepatic injury was not drug-related. A subsequent 6-month toxicology study in HAV-vaccinated cynomolgus monkeys confirmed the absence of hepatotoxicity. Identification of HAV infection supported progression of the drug candidate into later clinical trials. Although rarely investigated, subclinical HAV infection has occasionally been reported in laboratory primates, including those used for toxicology studies and it may be more prevalent than the literature indicates.

Decreasing parvovirus B19 and hepatitis A nucleic acid test positivity rates in Canadian plasma donors following the initiation of COVID-19 restriction in March 2020.

BACKGROUND AND OBJECTIVES: In Canada, plasma sent for fractionation is tested for both parvovirus B19 (B19V) and hepatitis A virus (HAV). This study compared positivity rates of B19 and HAV nucleic acid tests (NATs) in Canadian plasma samples for the pre-COVID-19 restriction era (2015 to end of February 2020 [Q1] 2020) and the post-COVID-19 restriction era. MATERIALS AND METHODS: Pooled EDTA plasma specimens were tested within 24 months of blood draw using the Procleix Panther System (Grifols Diagnostic Solutions Inc, San Diego, CA, USA) for B19V and HAV detection. Reactive pools were resolved by individual specimen testing. RESULTS: Between 1 January 2015, and 31 March 2022, 3,928,619 specimens from Canadian plasma donors were tested for B19V. For the same period, 3,922,954 specimens were tested for HAV. To account for a lag in specimen testing for up to 24 months, the data were divided into: (1) a pre-pandemic period (1 January 2015-31 March 2020; B19V tested n = 2,412,701, B19V NAT-positive n = 240 [0.01%], HAV tested n = 2,407,036, HAV NAT-positive n = 26 [0.001%]); (2) a two-year mixed-impact period (1 April 2020-31 March 2022; B19V tested n = 968,250, B19V NAT-positive n = 14 [0.001%], HAV tested n = 968,250, HAV NAT-positive n = 2 [0.0002%]); and (3) a pandemic-impact period (1 April 2022-31 March, 2023; B19V tested n = 597,668, B19V NAT-positive n = 3 [0.0005%], HAV tested n = 597,668, HAV NAT-positive n = 1 [0.0002%]). CONCLUSION: The percentage of B19V- and HAV-positive donations was significantly reduced from the pre-pandemic period to the pandemic-impact period.

Trends of Hepatitis A Virus Infection in Poland: Assessing the Potential Impact of the COVID-19 Pandemic and War in Ukraine.

Hepatitis A virus (HAV) is the most common cause of acute viral hepatitis, which is preventable by vaccination. This study analyzed trends of HAV infections in Poland according to socio-demographic features in the years 2009-2022 and assessed the potential impact of the COVID-19 pandemic (2020-2023) and the migration of war refugees from Ukraine (since February 2022). In 2009-2022, 7115 new cases of HAV infection were diagnosed in Poland, especially among men (66.4%) and in urban areas (77.4%). Infections among men were most common at the age of 25-34 (median rate 0.43 per 105) and in women aged 15-24 (median rate 0.39 per 105). Analysis of the 14-year frequency of HAV infections exhibited three trends, regardless of gender, age, and residence. The infections revealed a downward trend in 2009-2014, increased significantly in 2014-2018, and decreased again after 2018. A particularly rapid increase in HAV infections occurred between March 2017 and February 2018 (median rate 0.79 per 105). The high level of new infections persisted until the beginning of the COVID-19 pandemic, at which point it dropped significantly but did not reach the level recorded before March 2017. During the Omicron SARS-CoV-2 dominance period, the median rate of HAV infections was 0.053 per 105, with a four-fold increase being observed from February 2022 (when the migration of war refugees from Ukraine began) to August 2022. The presented results can serve as a reference point for further observations in Central Europe. The HAV epidemiological situation is unlikely to escalate in Poland but requires further monitoring.