The large virus family Paramyxoviridae includes some of the most significant human and livestock viruses, such as measles-, distemper-, mumps-, parainfluenza-, Newcastle disease-, respiratory syncytial virus and metapneumoviruses. Here we identify an estimated 66 new paramyxoviruses in a worldwide sample of 119 bat and rodent species (9,278 individuals). Major discoveries include evidence of an origin of Hendra- and Nipah virus in Africa, identification of a bat virus conspecific with the human mumps virus, detection of close relatives of respiratory syncytial virus, mouse pneumonia- and canine distemper virus in bats, as well as direct evidence of Sendai virus in rodents. Phylogenetic reconstruction of host associations suggests a predominance of host switches from bats to other mammals and birds. Hypothesis tests in a maximum likelihood framework permit the phylogenetic placement of bats as tentative hosts at ancestral nodes to both the major Paramyxoviridae subfamilies (Paramyxovirinae and Pneumovirinae). Future attempts to predict the emergence of novel paramyxoviruses in humans and livestock will have to rely fundamentally on these data.

A nomenclature is described for restriction endonucleases, DNA methyltransferases, homing endonucleases and related genes and gene products. It provides explicit categories for the many different Type II enzymes now identified and provides a system for naming the putative genes found by sequence analysis of microbial genomes.

Hepatitis C virus (HCV) is among the most relevant causes of liver cirrhosis and hepatocellular carcinoma. Research is complicated by a lack of accessible small animal models. The systematic investigation of viruses of small mammals could guide efforts to establish such models, while providing insight into viral evolutionary biology. We have assembled the so-far largest collection of small-mammal samples from around the world, qualified to be screened for bloodborne viruses, including sera and organs from 4,770 rodents (41 species); and sera from 2,939 bats (51 species). Three highly divergent rodent hepacivirus clades were detected in 27 (1.8%) of 1,465 European bank voles (Myodes glareolus) and 10 (1.9%) of 518 South African four-striped mice (Rhabdomys pumilio). Bats showed anti-HCV immunoblot reactivities but no virus detection, although the genetic relatedness suggested by the serologic results should have enabled RNA detection using the broadly reactive PCR assays developed for this study. 210 horses and 858 cats and dogs were tested, yielding further horse-associated hepaciviruses but none in dogs or cats. The rodent viruses were equidistant to HCV, exceeding by far the diversity of HCV and the canine/equine hepaciviruses taken together. Five full genomes were sequenced, representing all viral lineages. Salient genome features and distance criteria supported classification of all viruses as hepaciviruses. Quantitative RT-PCR, RNA in-situ hybridisation, and histopathology suggested hepatic tropism with liver inflammation resembling hepatitis C. Recombinant serology for two distinct hepacivirus lineages in 97 bank voles identified seroprevalence rates of 8.3 and 12.4%, respectively. Antibodies in bank vole sera neither cross-reacted with HCV, nor the heterologous bank vole hepacivirus. Co-occurrence of RNA and antibodies was found in 3 of 57 PCR-positive bank vole sera (5.3%). Our data enable new hypotheses regarding HCV evolution and encourage efforts to develop rodent surrogate models for HCV.

Hepatitis B envelope antigen (HBeAg) seroconversion represents an endpoint of treatment of chronic hepatitis B virus (HBV) infections. We have studied whether levels of serum HBV RNA during polymerase inhibitor treatment might be helpful for predicting HBeAg seroconversion. HBV RNA levels were determined in serial serum samples from 62 patients with chronic HBV infection (50 HBeAg positive). Patients received antiviral treatment for a mean duration of 30 6 15 (range, 4-64) months. A new rapid amplification of complimentary DNA-ends-based real-time polymerase chain reaction was established for quantitative analysis of polyadenylated full-length (fl) and truncated (tr) HBV RNA. HBV RNA, HBV DNA, and hepatitis B surface antigen (HBsAg) levels as well as presence of HBeAg and hepatitis B envelope antibody were measured at baseline, month 3, month 6, and subsequent time points. Fifteen patients who achieved HBeAg seroconversion after a mean duration of 19 6 14 (range, 3-56) months of antiviral treatment showed a significantly stronger decline in mean HBV flRNA and trRNA levels from baseline to month 3 of 1.0 6 1.4 (range, 21.6-3.4) and 2.1 6 1.4 (range, 0-3.9) and to month 6 of 1.8 6 1.4 (range, 0-4.6) and 3.1 6 1.7 (range, 0-5.1) log 10 copies/mL, respectively, in comparison to 35 HBeAg-positive patients without HBeAg seroconversion (P < 0.001 for months 3 and 6). A similar decline in HBV RNA levels was observed in HBeAg-negative patients. The decline of HBV RNA levels at months 3 and 6 of treatment was to be the strongest predictor of HBeAg seroconversion, when compared to levels of HBV DNA, HBsAg, alanine aminotransferase, and HBV genotype, age, and sex. Conclusion: Serum HBV RNA levels may serve as a novel tool for prediction of serological response during polymerase inhibitor treatment in HBeAg-positive patients. (HEPATOLOGY 2015;61:66-76)