Designing the fusion protein of rotavirus VP8 and hepatitis A virus VP1 and evaluating the immunological response in BALB/c mice.

Background and Objectives: Rotavirus and Hepatitis A virus are responsible for causing gastroenteritis and jaundice. The current vaccination approaches have proven insufficient, especially in low-income countries. In this study, we presented a novel dual-vaccine candidate that combines the rotavirus VP8 protein and the hepatitis A virus VP1. Materials and Methods: The VP8*-rotavirus+AAY+HAV-VP1 fusion protein was produced using an Escherichia coli expression system. The recombinant protein had a molecular weight of approximately 45.5 kDa and was purified through affinity chromatography. BALB/c mice were injected subcutaneously with the recombinant protein, VP1, VP8 and vaccines for rotavirus and hepatitis A virus, both with and without ALUM and M720 adjuvants. ELISA assays were used to measure total IgG, IgG1, IgG2, and short-term and long-term IL-5 and IFN-γ responses. Results: The fusion protein, when combined with adjuvants, elicited significantly higher total IgG, IgG1, and IgG2 responses compared to VP1 and VP8 alone, as well as the rotavirus and hepatitis A vaccines. Furthermore, it induced a higher short-term IL-5 and IFN-γ response while demonstrating a higher long-term IL-5 response compared to the rotavirus and hepatitis A vaccines. Conclusion: This study demonstrates that the VP8*-rotavirus+AAY+HAV-VP1 fusion protein is a promising dual vaccine candidate for immunization against hepatitis A and rotaviruses.

Surface Display of Duck Hepatitis A Virus Type 1 VP1 Protein on Bacillus subtilis Spores Elicits Specific Systemic and Mucosal Immune Responses on Mice.

Duck viral hepatitis, primarily caused by duck hepatitis A virus type 1 (DHAV-1), poses a significant threat to the global duck industry. Bacillus subtilis is commonly utilized as a safe probiotic in the development of mucosal vaccines. In this study, a recombinant strain of B. subtilis, designated as B. subtilis RV, was constructed to display the DHAV-1 capsid protein VP1 on its spore surface using the outer coat protein B as an anchoring agent. The immunogenicity of this recombinant strain was evaluated in a mouse model through mixed feeding immunization. The results indicated that B. subtilis RV could elicit specific systemic and mucosal immune responses in mice, as evidenced by the high levels of serum IgG, intestinal secretory IgA, and potent virus-neutralizing antibodies produced. Furthermore, the recombinant strain significantly upregulated the expression levels of IL-2, IL-6, IL-10, TNF-α, and IFN-γ in the intestinal mucosa. Thus, the recombinant strain maintained the balance of the Th1/Th2 immune response and demonstrated an excellent mucosal immune adjuvant function. In summary, this study suggests that B. subtilis RV can be a novel alternative for effectively controlling DHAV-1 infection as a vaccine-based feed additive.

Modeling hepatitis A epidemiological profiles and estimating the pediatric vaccination threshold in the Russian Federation.

Background: To combat the hesitancy towards implementing a hepatitis A universal mass vaccination (UMV) strategy and to provide healthcare authorities with a comprehensive analysis of the potential outcomes and benefits of the implementation of such a vaccination program, we projected HAV seroprevalence and incidence rates in the total population of the Russian Federation and estimated the pediatric vaccination threshold required to achieve an incidence level of less than 1 case per 100,000 using a new mathematical model. Methods: A dynamic age-structured SEIRV (susceptible-exposed-infectious-recovered-vaccinated) compartmental model was developed and calibrated using demographic, seroprevalence, vaccination, and epidemiological data from different regions of the Russian Federation. This model was used to project various epidemiological measures. Results: The projected national average age at the midpoint of population immunity increases from 40 years old in 2020 to 50 years old in 2036 and is shifted even further to the age of 70 years in some regions of the country. An increase of varying magnitude in the incidence of symptomatic HAV infections is predicted for all study regions and for the Russian Federation as a whole between 2028 and 2032, if the HAV vaccination coverage level remains at the level of 2022. The national average vaccination coverage level required to achieve a symptomatic HAV incidence rate below 1 case per 100,000 by 2032 was calculated to be 69.8% if children aged 1-6 years are vaccinated following the implementation of a UMV program or 34.8% if immunization is expanded to children aged 1-17 years. Conclusion: The developed model provides insights into a further decline of herd immunity to HAV against the background of ongoing viral transmission. The current favorable situation regarding hepatitis A morbidity is projected to be replaced by an increase in incidence rates if vaccination coverage remains at the current levels. The obtained results support the introduction of a hepatitis A UMV strategy in the Russian Federation.

Concurrently Affected by Dengue and Hepatitis A: Exploring the Intricacies of Co-infection in a Comprehensive Case Series.

Based on the examination of four distinct cases, this case series offers a thorough investigation of the intricate relationship between dengue fever and hepatitis A infection. Despite their distinct origins, both illnesses manifest overlapping clinical features, posing considerable diagnostic hurdles, particularly in endemic regions. The cases reveal consistent symptoms such as elevated fever, abdominal discomfort, jaundice, and irregular liver function test results, underscoring the intricate nature of an accurate diagnosis. Variations in age distribution and the severity of symptoms underscore the necessity for tailored treatment approaches. Diagnostic challenges stem from the similarity in clinical presentations and shared laboratory abnormalities, necessitating comprehensive serological assessments. Therapeutic strategies entail a multidisciplinary approach addressing both hepatic and systemic manifestations, with supportive measures ensuring favorable clinical outcomes. Despite the complexities involved, timely interventions facilitate gradual symptom amelioration and successful patient recovery. Informing clinical practice and directing public health actions, this case series provides insightful information about the diagnostic and treatment complications associated with co-occurring dengue fever and hepatitis A infection.

Reconstruction of the historic time course of blood-borne virus contamination of clotting factor concentrates, 1974-1992.

Factor VIII and IX clotting factor concentrates manufactured from pooled plasma have been identified as potent sources of virus infection in persons with hemophilia (PWHs) in the 1970s and 1980s. To investigate the range and diversity of viruses over this period, we analysed 24 clotting factor concentrates for several blood-borne viruses. Nucleic acid was extracted from 14 commercially produced clotting factors and 10 from nonremunerated donors, preserved in lyophilized form (expiry dates: 1974-1992). Clotting factors were tested by commercial and in-house quantitative PCRs for blood-borne viruses hepatitis A, B, C and E viruses (HAV, HBV, HCV, HEV), HIV- types 1/2, parvoviruses B19V and PARV4, and human pegiviruses types 1 and 2 (HPgV-1,-2). HCV and HPgV-1 were the most frequently detected viruses (both 14/24 tested) primarily in commercial clotting factors, with frequently extremely high viral loads in the late 1970s-1985 and a diverse range of HCV genotypes. Detection frequencies sharply declined following introduction of virus inactivation. HIV-1, HBV, and HAV were less frequently detected (3/24, 1/24, and 1/24 respectively); none were positive for HEV. Contrastingly, B19V and PARV4 were detected throughout the study period, even after introduction of dry heat treatment, consistent with ongoing documented transmission to PWHs into the early 1990s. While hemophilia treatment is now largely based on recombinant factor VIII/IX in the UK and elsewhere, the comprehensive screen of historical plasma-derived clotting factors reveals extensive exposure of PWHs to blood-borne viruses throughout 1970s-early 1990s, and the epidemiological and manufacturing parameters that influenced clotting factor contamination.

Comparison of Anti-Hepatitis A Antibody Pharmacokinetics in Healthy Australian Subjects Receiving Standard or Weight-Based Dosing of Polyvalent Immunoglobulin.

This randomized controlled trial compared two dosing regimens of the polyvalent immunoglobulin available for hepatitis A post-exposure prophylaxis in Australia. Participants were randomized to receive either 270 IU (standard dose) or 3.375 IU/kg (dose by weight). Quantitative serial serum hepatitis A antibody concentrations were measured at baseline and then on days 1, 3, 7, 28, and 50. Fifteen participants completed the trial. Serum hepatitis A antibody concentrations were not different between the study groups at any time point. Pharmacokinetic parameters estimated from participant data were not different between the study groups. The hepatitis A antibody level of all participants exceeded 10 mIU/mL at day 50. While no difference between dosing regimens was found in this study, further research should examine dosing at the lower limit of current Australian recommendations before making policy decisions.

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 glucose-6-phosphate dehydrogenase (G6PD) deficiency among the fulminant hepatitis A virus infection patients.

Background: Hepatitis A is a widespread viral infection with significant public health implications. Assessing glucose 6-phosphate dehydrogenase (G6PD) deficiency in hepatitis A patients is essential for various reasons, including prognosis, disease severity evaluation, encephalopathy risk identification, tailored management, and advancing scientific understanding. This study aimed to investigate the prevalence and clinical implications of G6PD impairment in individuals with fulminant hepatitis A. Methods: A cross-sectional descriptive analysis was conducted, involving hospitalized patients with fulminant hepatitis A. Demographic data, prevalence rates, and clinical findings were recorded in a database. The diagnosis of hepatitis A infection was confirmed using an anti-HAV IgM antibody test, and G6PD enzyme activity was measured with a fluorescent spot assay. Results: Out of 81 patients with hepatitis A, 57 (70.4%) were males, and 24 (29.5%) were females, with an average age of 24.6 years. Dark yellow urine and anorexia were the most common clinical symptoms. Notably, 30 (37%) patients lacked G6PD. The group with G6PD deficiency showed significantly higher rates of encephalopathy and mortality (P<0.01), along with elevated bilirubin (P=0.00), abnormal coagulation parameters, and low hemoglobin levels (P=0.00). Conclusion: In light of these findings, the present study proposes the implementation of routine G6PD level assessments and the evaluation of other relevant markers in regions where hepatitis A is endemic. Furthermore, the study underscores the need for vigilant monitoring of hemolysis and encephalopathy in affected patients to optimize clinical management and reduce morbidity and mortality associated with this condition.

Antibody persistence 7 years after hepatitis-A vaccine in children with human immunodeficiency virus infection.

BACKGROUND: HIV-infected children have a higher risk of presenting infections, including the hepatitis A virus (HAV). The inactivated HAV vaccine is immunogenic in immunocompetent hosts; however, there are insufficient studies on the duration of seroprotection in HIV-infected children. METHODS: An analytical cohort study was conducted. HIV-1-infected children who received the inactivated HAV vaccine (2 doses) were included. Blood samples were taken for antibody measurement, the first one 28 days after the second dose and another 7 years after the vaccination schedule. Information on viral load, immunological category, weight, height, and response to antiretroviral treatment from diagnosis to the last assessment was obtained. RESULTS: 19 patients were included, with a mean age of 12.6 years (SD ± 2.29). 58% were male. 80% of the patients presented protective immunoglobulin G antibodies against HAV 7-year post-vaccination. The antibody concentration was found to be between 13 and 80 mIU/mL (median of 80 mIU/mL). 52% showed some degree of immunosuppression. There was no statistically significant relationship between the presence of seroprotection and viral load, treatment failure, immunological category, and malnutrition. Twelve patients presented with antiretroviral treatment failure, and in 33% of them, the antibodies did not offer satisfactory seroprotection. CONCLUSION: 7-year post-vaccination, 80% of HIV-infected children maintain seroprotection titers against HAV.

INTRODUCCIÓN: Los niños infectados por el virus de la inmunodeficiencia humana (VIH) tienen mayor riesgo de presentar infecciones, incluyendo hepatitis por virus A (VHA). La vacuna inactivada contra el VHA es inmunógena en el huésped inmunocompetente. No hay estudios suficientes sobre el tiempo de seroprotección en niños infectados por el VIH. MÉTODO: Estudio de cohorte, analítico. Se incluyeron niños con infección por VIH-1 que recibieron la vacuna inactivada contra el VHA (dos dosis). Se les tomaron muestras sanguíneas para medición de anticuerpos, una 28 días después de la segunda dosis y otra 7 años después del esquema de vacunación. Se obtuvo información de carga viral, categoría inmunológica, peso y talla, y respuesta al tratamiento antirretroviral desde el diagnóstico hasta la última valoración. RESULTADOS: Se incluyeron 19 pacientes con una edad media de 12.6 años (± 2.29). El 58% fueron del sexo masculino. El 80% de los pacientes presentaron anticuerpos immunoglobulin G (IgG) contra el VHA protectores a los 7 años de la vacunación. La concentración de anticuerpos se encontró entre 13 y 80 mUI/ml (mediana: 80 mUI/ml). El 52% mostraron algún grado de inmunosupresión. No existe relación estadísticamente significativa entre la presencia de seroprotección y la carga viral, la falla al tratamiento, la categoría inmunológica ni la desnutrición. Doce pacientes presentaron falla al tratamiento antirretroviral; en el 33% de ellos los anticuerpos no ofrecían seroprotección satisfactoria. CONCLUSIONES: A 7 años posvacunación, el 80% de los niños con VIH mantienen títulos de seroprotección frente al VHA.

Hepatitis A virus infection associated with bilateral pleural effusion, ascites, and acalculous cholecystitis in childhood: a case report.

BACKGROUND: Acute hepatitis A infection is common among children in developing nations. The clinical presentation in children is usually asymptomatic and anicteric, and it is a self-limiting infection. Rarely, it can be associated with extrahepatic complications such as pleural effusion, acalculous cholecystitis, and ascites. CASE PRESENTATION: An 8-year-old middle eastern child presented with abdominal pain, jaundice in the sclera, yellowish color of urine, and poor appetite. In the last two days, abdominal distension developed. After conducting diagnostic investigations, the child was diagnosed with HAV hepatitis associated with bilateral pleural effusion, acalculous cholecystitis, and ascites. He was managed conservatively with vitamin K supplementation and supportive parenteral fluids. After 4 days, clinical improvement was observed. CONCLUSION: Hepatitis A infections presented with extrahepatic manifestations like pleural effusion, acalculous cholecystitis, and ascites are very rare, especially in children. There have been some reports of these manifestations occurring in isolation, but for them to co-exist to our knowledge, this has only been reported in two cases in the literature, and this is the third case with all these three rare complications being presented simultaneously in a single child. Although HAV infection is an asymptomatic and self-limiting viral disease in childhood, it can manifest with rare extrahepatic complications, so pediatricians should be aware of this rare association to avoid unnecessary investigations.

Therapeutic plasma exchange provides native liver survival benefit in children with acute liver failure: A propensity score-matched analysis.

OBJECTIVES: This study aimed to evaluate the safety and efficacy of therapeutic plasma exchange (TPE) in pediatric acute liver failure (PALF). METHODS: All children aged 2-18 years with PALF were included. The intervention cohort included a subset of PALF patients undergoing complete three sessions of TPE, whereas the matching controls were derived by propensity score matching from the patient cohort who did not receive any TPE. Propensity matching was performed based on the international normalized ratio (INR), grade of hepatic encephalopathy (HE), age, bilirubin, and ammonia levels. The primary outcome measure was native liver survival (NLS) in the two arms on day 28. RESULTS: Of the total cohort of 403 patients with PALF, 65 patients who received TPE and 65 propensity-matched controls were included in analysis. The 2 groups were well balanced with comparable baseline parameters. On day 4, patients in the TPE group had significantly lower INR (P = 0.001), lower bilirubin (P = 0.008), and higher mean arterial pressure (MAP) (P = 0.033) than controls. The NLS was 46.15% in the TPE arm and 26.15% in the control arm. The overall survival (OS) was 50.8% in the TPE arm and 35.4% in the control arm. Kaplan-Meier survival analysis showed a significantly higher NLS in patients receiving TPE than controls (P = 0.001). On subgroup analysis, NLS benefit was predominantly seen in hepatitis A-related and indeterminate PALF. CONCLUSION: TPE improved NLS and OS in a propensity-matched cohort of patients with PALF. Patients receiving TPE had lower INR and bilirubin levels and higher MAP on day 4.

Concomitant Occurrence of Hepatitis A and a Pyogenic Liver Abscess: A Pediatric Case.

Pyogenic liver abscess (PLA) and hepatitis A are common in developing countries. As there is an overlap of clinical features, a diagnosis of dual infection can be missed. Here, we present the case of a five-year-old male who presented with abdominal pain, fever, and jaundice diagnosed as a complicated liver abscess with concurrent hepatitis A. To our knowledge, this is the first case where a PLA co-existed with hepatitis A. Simultaneous infection should be considered when a patient with liver abscess presents with jaundice, especially in areas where both diseases are endemic. Early diagnosis of both is crucial as PLA is a potentially fatal disease and co-infection with hepatitis A may worsen clinical outcomes.

Beyond the Liver: Unveiling Rhabdomyolysis as a Rare Complication of Hepatitis A.

Hepatitis A is a mild self-limiting infection of the liver with spontaneous resolution of symptoms in most cases. However, clinicians should be aware of some commonly encountered complications and extrahepatic manifestations associated with hepatitis A for timely diagnosis and treatment. Rhabdomyolysis, an exceedingly rare complication of hepatitis A, is scarcely documented. We present a case of a 64-year-old man with symptoms consistent with rhabdomyolysis and an evanescent rash secondary to acute hepatitis A. He eventually recovered with conservative management. This case emphasizes the importance of recognizing and treating atypical presentations of acute hepatitis A infection. LEARNING POINTS: Recognition of atypical presentations: The case underscores the importance of recognizing and treating atypical presentations of acute hepatitis A infection. Clinicians should be vigilant for unusual manifestations of common infections, facilitating timely diagnosis and appropriate management.Understanding rare complications: Rhabdomyolysis is identified as an exceedingly rare complication of hepatitis A infection, which is scarcely documented in the literature. This case contributes to the growing understanding of extrahepatic manifestations associated with hepatitis A, emphasizing the importance of considering uncommon complications in the differential diagnosis, especially when typical clinical presentations are observed.Management strategies: The article discusses the treatment approach for rhabdomyolysis secondary to acute hepatitis A, which involves aggressive fluid resuscitation to prevent kidney damage from myoglobinuria, correction of electrolyte imbalances, and metabolic abnormalities. Additionally, vaccination against hepatitis A and advocating for sanitation measures are highlighted as important preventive strategies.

Exploring the Epidemiological Surveillance of Hepatitis A in South Africa: A 2023 Perspective.

Hepatitis A (HAV) presents a significant global health concern with diverse clinical manifestations primarily transmitted through fecal-oral routes, emphasizing the critical role of sanitation and water cleanliness in transmission dynamics. Age-related variations, notably asymptomatic presentation in children, add complexity. The World Health Organization's (WHO) endemicity classification aids in understanding prevalence and control strategies. This study examines 2023 South African epidemiological data on HAV cases, evaluating age distribution, incidence rates, and provincial disparities. Data from the national surveillance system and weather services were analyzed. Findings reveal distinct age-related trends, with the highest seroprevalence observed in the 5-9 age group with the most burdened areas located in the Western Cape, KwaZulu-Natal, and Gauteng provinces. Furthermore, seasonal rainfall variations correlate with increased incidence in Western Cape and KZN. The amalgamation of results suggest a potential epidemiological shift, emphasizing the need for updated immunization strategies. Noteworthy patterns, like the rise in 5-9-year-olds, may be influenced by factors such as school clustering and migration. Provincial disparities and the impact of climatic events underscore the necessity for dynamic vaccination strategies and surveillance network enhancements. This study highlights the urgency for improved understanding and response to HAV in South Africa.

Identification and Genomic Characterization of Two Novel Hepatoviruses in Shrews from Yunnan Province, China.

Hepatitis A virus (HAV), a member of the genus Hepatovirus (Picornaviridae HepV), remains a significant viral pathogen, frequently causing enterically transmitted hepatitis worldwide. In this study, we conducted an epidemiological survey of HepVs carried by small terrestrial mammals in the wild in Yunnan Province, China. Utilizing HepV-specific broad-spectrum RT-PCR, next-generation sequencing (NGS), and QNome nanopore sequencing (QNS) techniques, we identified and characterized two novel HepVs provisionally named EpMa-HAV and EpLe-HAV, discovered in the long-tailed mountain shrew (Episoriculus macrurus) and long-tailed brown-toothed shrew (Episoriculus leucops), respectively. Our sequence and phylogenetic analyses of EpMa-HAV and EpLe-HAV indicated that they belong to the species Hepatovirus I (HepV-I) clade II, also known as the Chinese shrew HepV clade. Notably, the codon usage bias pattern of novel shrew HepVs is consistent with that of previously identified Chinese shrew HepV. Furthermore, our structural analysis demonstrated that shrew HepVs differ from other mammalian HepVs in RNA secondary structure and exhibit variances in key protein sites. Overall, the discovery of two novel HepVs in shrews expands the host range of HepV and underscores the existence of genetically diverse animal homologs of human HAV within the genus HepV.

Healthcare and Epidemiological Surveillance Costs of Hepatitis A Outbreaks in Spain in Regions with and without Universal Hepatitis A Vaccination of Children during 2010-2018.

The aim of this study was to evaluate and compare hepatitis A outbreak-associated healthcare and epidemiological surveillance costs in Spain in two types of autonomous regions during 2010-2018: (1) regions with a prevention strategy based on universal hepatitis A vaccination of children and vaccination of high-risk population groups (Catalonia) and (2) regions with a prevention strategy based on vaccinating high-risk population groups (Castile and Leon, Murcia, Navarra, Community of Madrid, Community of Valencia). Healthcare costs were determined based on the resources used to treat hepatitis A outbreak-associated cases and hospitalizations. Epidemiological surveillance costs were calculated from the resources used during surveillance activities. The ratios for total, healthcare and epidemiological surveillance costs (regions without universal hepatitis A vaccination of children vs. Catalonia) were used to compare the two hepatitis A prevention strategies. From 2010 to 2018, the total, healthcare and epidemiological surveillance costs per million population were 1.75 times (EUR 101,671 vs. EUR 58,032), 1.96 times (EUR 75,500 vs. EUR 38,516) and 1.34 times greater (EUR 26,171 vs. EUR 19,515) in regions without universal hepatitis A vaccination of children than in Catalonia, respectively. The ratios tended to increase over time during 2010-2018. In 2015-2018, total, healthcare and epidemiological surveillance costs per million population were 2.68 times (EUR 69,993 vs. EUR 26,158), 2.86 times (EUR 53,807 vs. EUR 18,825) and 2.21 times greater (EUR 16,186 vs. EUR 7333) in regions without universal hepatitis A vaccination of children than in Catalonia, respectively. These findings suggest that universal hepatitis A vaccination of children could reduce hepatitis A outbreak-associated costs.

Hepatitis A virus subtype IB outbreak among MSM in Hungary with a link to a frozen berry source.

Men who have sex with men (MSM) are at high risk of acquiring hepatitis A virus (HAV) and in recent years several HAV outbreaks mostly affecting MSM have been described. These outbreaks were caused by subtype IA strains circulating in this high-risk population. After years of low incidence, an outbreak among MSM in Hungary caused a significant increase in reported HAV infections in 2022. Samples from 224 HAV IgM-positive patients diagnosed in 2022 were tested for HAV RNA and positive samples were genotyped by sequencing. In 171 patients a unique subtype IB virus was detected with 99.8-100% sequence identity in the VP1/P2A junction. It was distinct from previously published strains, but most closely related to an Egyptian isolate. Sequence analysis revealed one dominant and three minor variants based on VP1/P2A. Whole genome sequencing revealed limited variation among these variants, suggesting a recent common origin. Epidemiological data indicated that sexual transmission was driving the outbreak for most of the year, suggested by the high male to female ratio and the large number of coinfections with HIV and other sexually transmitted infections among the patients. The outbreak was also associated with a restaurant cluster, in which one of the variants was detected and frozen berries were implicated as the source of infections. The outbreak strain was also detected in other countries around Europe and remained frequently detectable in Hungary in 2023. This study provides insights into the molecular and epidemiological characteristics of the described HAV outbreak. The results show that sequencing is not only useful in connecting cases to an outbreak, but also helps to clarify the relatedness of detected variants. Prevention strategies focusing on vulnerable communities may reduce the burden of HAV infections in the future.

Seroprevalence of hepatitis A virus among people born before and after implementation of universal vaccination in Argentina.

BACKGROUND: Until 2005, when a single dose of vaccine was implemented in one-year-old children, the Hepatitis A virus (HAV) was responsible for approximately 90% of acute hepatitis cases in the paediatric population in Argentina. However, despite vaccination success, sporadic outbreaks of HAV still occur among adults. This study aimed to assess the seroepidemiology of HAV in Argentina, analysing IgG and IgM antibodies against HAV in a large population, both vaccinated and unvaccinated. METHODS: The study included 16,982 patients attending a hospital from 2001 to 2023. The cohort was divided into two groups: 16,638 individuals who were not reached by the vaccination program implemented in 2005 and 344 children who were covered by the universal vaccination. RESULTS: Anti-HAV IgG was detected in 56.7% of cases. The rate was significantly higher in individuals born after 2005 (77.7%) compared to those born before (56.3%), p < 0.001. The age groups 19-40 and 41-60 years showed the anti-HAV IgG lowest rates. On the other hand, 100/3956 cases (2.5%) with suspected acute hepatitis were positive for Anti-HAVIgM. Notably, none of these were born after the mandatory vaccine rollout. CONCLUSIONS: The study of this large cohort contributes to the understanding of the seroepidemiology of HAV. Although the implementation of the vaccine achieved its main goal, the age segment between 19 and 60 years does not reach the estimated threshold to achieve herd immunity. These findings reveal the importance of targeting vaccination campaigns, provide essential insights for public health planning, and guide future immunisation strategies against HAV in Argentina.

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.

Detection of Foodborne RNA Viruses by Reverse Transcriptase Droplet Digital PCR.

Foodborne viruses remain the largest cause of human gastroenteritis and one of the largest contributors to foodborne illnesses worldwide. Currently, quantitative reverse transcription PCR (qRT-PCR) or real-time qPCR are the detection methods commonly used for quantification of foodborne viruses, but those methods have several disadvantages, such as relying on standard curves for quantification and the background noise from a bulk reaction. ddPCR uses an oil-water emulsion to form multiple droplets that partition small amounts of viral genetic material (DNA or RNA) into each of the droplets. These droplets then undergo amplification cycles and are analyzed using Poisson distributions. This allows for absolute quantification without the need for a standard curve, which makes ddPCR a precise tool in surveillance of foodborne viruses. Herein, we describe the process of detecting foodborne viruses using RNA isolated from various matrices. Up to 96 samples including the positive and negative controls can be analyzed on a single plate by ddPCR.