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Occult hepatitis B virus infection (OBI) characterized by the absence of detectable HBsAg remains a potential threat in blood safety. We investigated the actual prevalence, viral factors and genotype of OBI infections in Nigerian blood donors. Serum collected from two blood banks were reconfirmed as HBsAg seronegative by ELISA. Forty HBsAg positive samples were employed as controls. HBV-DNA was amplified from all donors and viral loads were determined using quantitative real-time PCR. Antibodies to the HBV core, surface and HBe antigen (anti-HBc,anti-HBs,HBeAg) were measured. The PreS/S and PreC/C regions of the HBV genome were sequenced. Of the 429 blood donors, 72(17%) were confirmed as OBI by DNA detection in different reference labs and excluded the concern of possible contamination. Of the 72 OBI samples, 48(67%) were positive for anti-HBc, 25(35%) positive for anti-HBs, and 2(3%) positive for HBeAg. Of the 72 OBI samples, 31(43%) were seropositive for either anti-HBc, anti-HBs or HBeAg, 21 (30%) positive for both anti-HBc and anti-HBs,one positive for both anti-HBc and HBeAg. None of the OBI samples were positive for all three serological markers. The viral load was <50copies/ml in the OBI samples and genotype E was predominant. The L217R polymorphism in the reverse transcriptase domain of the HBV polymerase gene was observed significantly higher in OBI compared with HBsAg positive individuals (P<0.0001). High incidence of OBI is relevant in high endemic areas worldwide and is a general burden in blood safety. This study signifies the high prevalence of OBI and proposes blood donor samples in Nigeria should be pre-tested for OBI by nucleic acid testing (NAT) and/or anti-HBc prior to transfusion to minimize the HBV infection risk.

The propensity of metals to form irregular and nonplanar electrodeposits at liquid-solid interfaces has emerged as a fundamental barrier to high-energy, rechargeable batteries that use metal anodes. We report an epitaxial mechanism to regulate nucleation, growth, and reversibility of metal anodes. The crystallographic, surface texturing, and electrochemical criteria for reversible epitaxial electrodeposition of metals are defined and their effectiveness demonstrated by using zinc (Zn), a safe, low-cost, and energy-dense battery anode material. Graphene, with a low lattice mismatch for Zn, is shown to be effective in driving deposition of Zn with a locked crystallographic orientation relation. The resultant epitaxial Zn anodes achieve exceptional reversibility over thousands of cycles at moderate and high rates. Reversible electrochemical epitaxy of metals provides a general pathway toward energy-dense batteries with high reversibility.

Avian hepatitis E virus (aHEV) is associated with hepatitis-splenomegaly syndrome, big liver and spleen disease and hepatic rupture haemorrhage syndrome. However, the knowledge about aHEV in commercial layer chickens in Nigeria is scarce. In this study, 460 serum samples obtained from 36 apparently healthy commercial layer chicken flocks in three states (Ogun, Osun and Oyo States) of southwestern Nigeria were analysed by enzyme linked immunosorbent assay for the presence of anti-aHEV immunoglobulin Y (IgY) antibodies. In total, the overall seroprevalence of anti-aHEV antibodies was 14.6%. The serological analysis revealed that 75% of the flocks examined were positive for anti-aHEV IgY antibodies from chickens of various ages in all three states. The percentage of the seropositive chickens in the three states varied from flock to flock ranging from 60% to 88.8% and seropositive chickens were detected at any age (24–52 weeks of age) without significant differences between the age groups. This is the first report assessing the presence of aHEV antibodies in chickens from Nigeria. The detection of anti-aHEV antibodies in commercial layer chickens in this study emphasizes the importance of serosurveillance in disease monitoring due to the economic threat posed by aHEV as a result of decreased egg production and increased mortality in affected commercial layer chicken farms. However, further studies are essential to reveal the clinical implications and to assess the real burden of aHEV in Nigeria.

Infection with hepatitis E virus (HEV) represents the most common source of viral hepatitis globally. Although infecting over 20 million people annually in endemic regions, with major outbreaks described since the 1950s, hepatitis E remains an underestimated disease. This review gives a current view of the global circulation and epidemiology of this emerging virus. The history of HEV, from the first reported enteric non-A non-B hepatitis outbreaks, to the discovery of the viral agent and the molecular characterization of the different human pathogenic genotypes, is discussed. Furthermore, the current state of research regarding the virology of HEV is critically assessed, and the challenges towards prevention and diagnosis, as well as clinical risks of the disease described. Together, these points aim to underline the significant impact of hepatitis E on global health and the need for further in-depth research to better understand the pathophysiology and its role in the complex disease manifestations of HEV infection.

The diagnosis of acute and chronic myocarditis remains a challenge for clinicians. Characterization of this disease has been hampered by its diverse etiologies and heterogeneous clinical presentations. Most cases of myocarditis are caused by infectious agents. Despite successful research in the last few years, the pathophysiology of viral myocarditis and its sequelae leading to severe heart failure with a poor prognosis is not fully understood and represents a significant public health issue globally. Most likely, at a certain point, besides viral persistence, several etiological types merge into a common pathogenic autoimmune process leading to chronic inflammation and tissue remodeling, ultimately resulting in the clinical phenotype of dilated cardiomyopathy. Understanding the underlying molecular mechanisms is necessary to assess the prognosis of patients and is fundamental to appropriate specific and personalized therapeutic strategies. To reach this clinical prerequisite, there is the need for advanced diagnostic tools, including an endomyocardial biopsy and guidelines to optimize the management of this disease. The severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2) has currently led to the worst pandemic in a century and has awakened a special sensitivity throughout the world to viral infections. This work aims to summarize the pathophysiology of viral myocarditis, advanced diagnostic methods and the current state of treatment options.

Hepatitis E virus (HEV) poses a significant global health threat, with an estimated 20 million infections occurring annually. Despite being a self-limiting illness, in most cases, HEV infection can lead to severe outcomes, particularly in pregnant women and individuals with pre-existing liver disease. In the absence of specific antiviral treatments, the exploration of RNAi interference (RNAi) as a targeted strategy provides valuable insights for urgently needed therapeutic interventions against Hepatitis E. We designed small interfering RNAs (siRNAs) against HEV, which target the helicase domain and the open reading frame 3 (ORF3). These target regions will reduce the risk of viral escape through mutations, as they belong to the most conserved regions in the HEV genome. The siRNAs targeting the ORF3 efficiently inhibited viral replication in A549 cells after HEV infection. Importantly, the siRNA was also highly effective at inhibiting HEV in the persistently infected A549 cell line, which provides a suitable model for chronic infection in patients. Furthermore, we showed that a 5′ triphosphate modification on the siRNA sense strand activates the RIG-I receptor, a cytoplasmic pattern recognition receptor that recognizes viral RNA. Upon activation, RIG-I triggers a signaling cascade, effectively suppressing HEV replication. This dual-action strategy, combining the activation of the adaptive immune response and the inherent RNAi pathway, inhibits HEV replication successfully and may lead to the development of new therapies.

Rodents are common reservoirs for numerous zoonotic pathogens, but knowledge about diversity of pathogens in rodents is still limited. Here, we investigated the occurrence and genetic diversity of enteric viruses in 51 Norway rats collected in three different countries in Europe. RNA of at least one virus was detected in the intestine of 49 of 51 animals. Astrovirus RNA was detected in 46 animals, mostly of rat astroviruses. Human astrovirus (HAstV-8) RNA was detected in one, rotavirus group A (RVA) RNA was identified in eleven animals. One RVA RNA could be typed as rat G3 type. Rat hepatitis E virus (HEV) RNA was detected in five animals. Two entire genome sequences of ratHEV were determined. Human norovirus RNA was detected in four animals with the genotypes GI.P4-GI.4, GII.P33-GII.1, and GII.P21. In one animal, a replication competent coxsackievirus A20 strain was detected. Additionally, RNA of an enterovirus species A strain was detected in the same animal, albeit in a different tissue. The results show a high detection rate and diversity of enteric viruses in Norway rats in Europe and indicate their significance as vectors for zoonotic transmission of enteric viruses. The detailed role of Norway rats and transmission pathways of enteric viruses needs to be investigated in further studies.

Owing to its high mortality rate, viral hepatitis is a major public health problem, especially in low-income countries. In Africa, hepatitis B virus (HBV) and hepatitis E virus (HEV) are highly endemic, and HBV/HEV coinfections, which are associated with more severe liver disease and poor outcomes, are common. HEV genotypes 1 and 2 have been associated with large human outbreaks, while 3 is known to circulate in pigs and sporadically in humans. In this study, the prevalence of HBV and HEV among individuals with acute or chronic liver diseases in Osun State, Southwest Nigeria, was analyzed. One hundred plasma samples from liver disease patients attending Ladoke Akintola University Teaching Hospital were analyzed for the presence of anti-HEV antibodies and hepatitis B surface antigen (HBsAg) via ELISA, and HEV RNA and HBV DNA were analyzed via RT‒PCR. Virus genotyping was performed by sequencing and subsequent phylogenetic analysis. Overall, 50 individuals (50%) were positive for HBsAg, of which 14 (28%) also tested positive for HBV DNA. Two individuals (2%) had occult HBV infection. Most HBV strains were genotype E, except for two genotype A (A2 and A3). Anti-HEV antibodies were detected in eight individuals (8%), with one (1%) being positive for anti-HEV IgM and seven (7%) for anti-HEV IgG. Nine (9%) samples had detectable HEV RNA, with one being HEV-3; a rare occurrence in Nigeria. Coinfection with HBV/HEV was detected in seven (7%) individuals. The prevalence of HEV in Nigeria is low, but considering the high prevalence of HBV and the possible complications due to HEV coinfection or superinfection, HEV screening and HBV vaccination targeting high-risk populations are emphasized.

Human group A rotaviruses (RVA) are important enteric pathogens, as they are a leading cause of acute gastroenteritis (AGE) in children worldwide. Since 2013, the German Standing Committee on vaccination recommended the routine rotavirus vaccination for infants in Germany. While vaccination has significantly decreased RVA cases and worldwide mortality, in some cases, infants can develop acute gastroenteritis as an adverse reaction after immunization with an attenuated live vaccine. Pediatricians, as well as clinicians and diagnostic laboratories, contacted the Consultant Laboratory for Rotaviruses and inquired whether cases of RVA-positive AGE after vaccination were associated with vaccine or with wild-type RVA strains. A testing algorithm based on distinguishing PCRs and confirmative sequencing was designed, tested, and applied. Diagnostic samples from 68 vaccinated children and six cases where horizontal transmission was suspected were investigated in this study. Using a combination of real-time PCR, fragment-length analysis of amplicons from multiplex PCRs and confirmative sequencing, vaccine-like virus was detected in 46 samples and wild-type RVA was detected in 6 samples. Three mixed infections of vaccine and wild-type RVA were detectable, no RVA genome was found in 19 samples. High viral loads (>1.0 × 107 copies/g stool) were measured in most RVA-positive samples. Furthermore, information on co-infections with other AGE pathogens in the vaccinated study population was of interest. A commercial multiplex PCR and in-house PCRs revealed three co-infections of vaccinated infants with bacteria (two samples with Clostridioides difficile and one sample with enteropathogenic E. coli) and six co-infections with norovirus in a subset of the samples. Human astrovirus was detected in one sample, with suspected horizontal transmission. The cases of suspected horizontal transmission of vaccine RVA strains could not be confirmed, as they either involved wild-type RVA or were RVA negative. This study shows that RVA-positive AGE after vaccination is not necessarily associated with the vaccine strain and provides a reliable workflow to distinguish RVA vaccine strains from wild-type strains.

Hepatitis E virus (HEV) is an emerging zoonotic pathogen that has received an increasing amount of attention from virologists, clinicians, veterinarians, and epidemiologists over the past decade. The host range and animal reservoirs of HEV are rapidly expanding and a plethora of emerging HEV variants have been recently identified, some of which have the potential for interspecies infection. In this review, the detection of genetically diverse HEV variants, classified into and presumably associated with the species Orthohepevirus C, currently comprising HEV genotypes C1 and C2, by either serological or molecular approach is summarized. The distribution, genomic variability, and evolution of Orthohepevirus C are analyzed. Moreover, the potential risk of cross-species infection and zoonotic transmission of Orthohepevirus C are discussed.