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Human parvovirus B19 (B19V) is a ubiquitous human pathogen associated with a number of conditions, such as fifth disease in children and arthritis and arthralgias in adults. B19V is thought to evolve exceptionally rapidly among DNA viruses, with substitution rates previously estimated to be closer to those typical of RNA viruses. On the basis of genetic sequences up to ∼70 years of age, the most recent common ancestor of all B19V has been dated to the early 1800s, and it has been suggested that genotype 1, the most common B19V genotype, only started circulating in the 1960s. Here we present 10 genomes (63.9–99.7% genome coverage) of B19V from dental and skeletal remains of individuals who lived in Eurasia and Greenland from ∼0.5 to ∼6.9 thousand years ago (kya). In a phylogenetic analysis, five of the ancient B19V sequences fall within or basal to the modern genotype 1, and five fall basal to genotype 2, showing a long-term association of B19V with humans. The most recent common ancestor of all B19V is placed ∼12.6 kya, and we find a substitution rate that is an order of magnitude lower than inferred previously. Further, we are able to date the recombination event between genotypes 1 and 3 that formed genotype 2 to ∼5.0–6.8 kya. This study emphasizes the importance of ancient viral sequences for our understanding of virus evolution and phylogenetics.

Dengue fever, caused by the mosquito-borne dengue virus (DENV), has been endemic in Myanmar since 1970 and it has become a significant public health burden. It is crucial that circulating DENV strains are identified and monitored, and that their transmission efficiency and association with disease severity is understood. In this study, we analyzed DENV-1, DENV-2, DENV-3, and DENV-4 serotypes in 1235 serum samples collected in Myanmar between 2017 and 2019. Whole-genome sequencing of DENV-1–4 demonstrated that most DENV-1–4 strains had been circulating in Myanmar for several years. We also identified the emergence of DENV-3 genotype-I in 2017 samples, which persisted through 2018 and 2019. The emergence of the strain coincided with a period of increased DENV-3 cases and marked changes in the serotype dynamics. Nevertheless, we detected no significant differences between serum viral loads, disease severity, and infection status of individuals infected with different DENV serotypes during the 3-year study. Our results not only identify the spread of a new DENV-3 genotype into Yangon, Myanmar, but also support the importance of DENV evolution in changing the epidemic dynamics in endemic regions.

The hepatitis delta virus (HDV) is a hepatotropic subvirus that is dependent on the hepatitis B virus (HBV) and supplies the viral envelope containing the surface antigen of hepatitis B. Viral genetic diversity is related to the geographical origin of the isolates, and there are at least eight genotypes that are referred to as HDV-1 through HDV-8. HDV-3 is responsible for epidemics of severe and fulminant hepatitis, which are common in northeastern South America. HDV-3 is prevalent in the Brazilian Amazon and is associated with the increased aggressiveness of HDV infections. Although isolated, the characteristics of the clinical presentation of HDV-1 in the Amazon region have not yet been clearly reported. Objective: This study aims to assess the genotypic and clinical characteristics of individuals with the HDV-1 genotype in the western Amazon region. Methods: The HDV was genotyped by nested PCR-RFLP and sequencing from serum samples of 56 patients with HBV/HDV infection. The genotypes were correlated with the clinical characteristics presented by patients with HBV/HDV infection. Results: A prevalence of 92.3% for the HDV-3 genotype (n = 48) and 7.6% (n = 4) for the HDV-1 genotype was observed. Conclusion: To date, this is the most extensive clinical study of HDV-1 genotype infections in the nonindigenous population of Western Amazonia.

Background Chemokines/cytokines play important roles in the pathogenesis of chronic hepatitis C (CHC). However, their clinical characteristics and implications in treatment responses to pegylated interferon plus ribavirin treatment (PegIFN/RBV) have not been fully illustrated yet. In this study, we intended to investigate the possible predictability of serum chemokines/cytokines on the treatment response in Taiwanese of CHC, genotype-1 (GT-1). Methods 60 Patients with GT-1 CHC infection who had been treated with PegIFN/RBV were enrolled, including 27 (45%) with sustained virological response (SVR), 11 (18%) with relapse after 48 weeks of treatment and 22 (37%) non-response (NR). Clinical parameters, seven chemokines/cytokines, CCL3, CCL4, CXCL9, CXCL10, CXCL11, IL-10 and IFN-γ, and genotypes of rs12979860, the single nucleotide polymorphisms (SNPs) of interleukin-28B (IL28B) were analyzed for their relationship to treatment response. Results Baseline serum levels of CXCL10, CXCL11, CCL3 and CCL4 were significantly higher in NR group while comparing with non-NR group. (CXCL10: p  = 0.001; CXCL11: p  < 0.001; CCL3: p  = 0.006; CCL4: p  = 0.005). However, only rs12979860 CC genotype was the independent factors for NR in GT-1 CHC infection (OR, 8.985; p  = 0.008). In addition, baseline serum level of CCL4 was found to be the only independent factor for NR in GT-1 CHC patients with favorable IL28B genotype (OR, 1.134; p  = 0.039). Conclusions IL28B genotype is the predictor for NR in GT-1 CHC patients treated with PegIFN/RBV, while baseline serum level of CCL4 is the only predictor for NR in GT-1 CHC patients with favorable IL28B genotype.

Viral hepatitis E is gaining importance as an emerging worldwide disease. Though viral hepatitis E (HEV) has been attributed as an etiology of acute liver failure (ALF), however its actual incidence and the immunopathogenesis are being under explored. The present study is aimed at detecting HEV in post mortem liver tissues of patients with undiagnosed ALF. Twenty six liver tissues of ALF patients died of unknown etiology are subjected to nested reverse transcriptase PCR with HEV ORF1 gene targeted primers and HEV RNA is detected in 30.4% (7/23) of ALF cases. Out of seven HEV RNA positive cases, three (42.8%) had HEV antigen positivity by immunohistochemistry on liver tissues using HEV ORF2 antibody. Histopathological examination by H&E staining shows multiacinar confluent hepatic necrosis, bile ductular proliferation, bridging hepatic and periportal necrosis in 4, 4, 2 and 1 cases respectively. The isolates were sequenced using RdRp gene specific primers and found to HEV genotype-1. Quantitative TaqMan real time PCR estimated the viral load ranged between 7.77 × 10 3 and 1.44 × 10 7 viral copies/µl. HEV has been associated with 30.4% (7/23) of undiagnosed ALF cases. Immuno-histochemistry along with molecular testing in FFPE biopsies might be useful for the detection of HEV in undiagnosed cases.