Varicella-zoster virus (VZV) is a human herpesvirus, which during primary infection typically causes varicella (chicken pox) and establishes lifelong latency in sensory and autonomic ganglia. Later in life, the virus may reactivate to cause herpes zoster (HZ; also known as shingles). To prevent these diseases, a live-attenuated heterogeneous vaccine preparation, vOka, is used routinely in many countries worldwide. Recent studies of another alphaherpesvirus, infectious laryngotracheitis virus, demonstrate that live-attenuated vaccine strains can recombine in vivo, creating virulent progeny. These findings raised concerns about using attenuated herpesvirus vaccines under conditions that favor recombination. To investigate whether VZV may undergo recombination, which is a prerequisite for VZV vaccination to create such conditions, we here analyzed 115 complete VZV genomes. Our results demonstrate that recombination occurs frequently for VZV. It thus seems that VZV is fully capable of recombination if given the opportunity, which may have important implications for continued VZV vaccination. Although no interclade vaccinewild-type recombinant strains were found, intraclade recombinants were frequently detected in clade 2, which harbors the vaccine strains, suggesting that the vaccine strains have already been involved in recombination events, either in vivo or in vitro during passages in cell culture. Finally, previous partial and complete genomic studies have described strains that do not cluster phylogenetically to any of the five established clades. The additional VZV strains sequenced here, in combination with those previously published, have enabled us to formally define a novel sixth VZV clade. IMPORTANCEAlthough genetic recombination has been demonstrated to frequently occur for other human alphaherpesviruses, herpes simplex viruses 1 and 2, only a few ancient and isolated recent recombination events have hitherto been demonstrated for VZV. In the present study, we demonstrate that VZV also frequently undergoes genetic recombination, including strains belonging to the clade containing the vOKA strain.

Human enteroviruses (EV) and parechoviruses (HPeV) within the family Picornaviridae are the most common causes of viral central nervous system (CNS)associated infections including meningitis and neonatal sepsis-like disease. The frequencies of EV and HPeV types identified in clinical specimens collected in Scotland over an eight-year period were compared to those identified in sewage surveillance established in Edinburgh. Of the 35 different EV types belonging to four EV species (A to D) and the four HPeV types detected in this study, HPeV3 was identified as the most prevalent picornavirus in cerebrospinal fluid samples, followed by species B EV. Interestingly, over half of EV and all HPeV CNS-associated infections were observed in young infants (younger than three months). Detection of species A EV including coxsackievirus A6 and EV71 in clinical samples and sewage indicates that these viruses are already widely circulating in Scotland. Furthermore, species C EV were frequently identified EV in sewage screening but they were not present in any of 606 EV-positive clinical samples studied, indicating their likely lower pathogenicity. Picornavirus surveillance is important not only for monitoring the changing epidemiology of these infections but also for the rapid identification of spread of emerging EV and/or HPeV types.

Human rhinoviruses (HRVs) can be divided into three species; HRV-A to HRV-C. Up to 148 different HRV (sero)types have been identified to date. Because of sequence similarity between 5'-NCR of HRVs and enteroviruses (EVs), it is problematic to design EV-specific RT-PCR assays. The aims of this study were to assess the rate of false-detection of different rhinoviruses by EV RT-PCR, and to evaluate the diagnostic and clinical significance of such cross-reactivity. In vitro RNA transcripts of HRV A-C created from cDNA templates were quantified spectrophotometrically. Six hundred twenty-one stool samples screened as part of routine diagnostic for EV, 17 EV-positive stool samples referred for typing, 288 stool samples submitted for gastroenteritis investigations, and 1,500 CSF samples were included in the study. EV-specific RT-PCR detected RNA transcripts of HRV-A1b, HRV-B14, and HRV-Crpat18 but with 10-1,000 reduced sensitivity compared to EV transcripts. Screening fecal samples by EV RT-PCR identified 13 positive samples identified subsequently as rhinoviruses; a further 26 HRV-positive samples were identified by nested HRV RT-PCR. All individuals were hospitalized and presented mostly with diarrhea. A total of 26 HRV types were identified (HRV-A: 46%; HRV-B: 13%; HRV-C: 41%). Results confirm that EV-specific RT-PCR can detect HRVs, and at a practical level, identify potential problems of interpretation if fecal samples are used for surrogate screening in cases of suspected viral meningitis. High detection frequencies (10%) and viral loads in stool samples provide evidence for enteric replication of HRV, and its association with enteric disease requires further etiological studies.

The introduction of DBS sampling in community drug services has made an appreciable contribution to efforts to diagnose the HCV-infected population in Scotland. These findings are important to other countries, with injecting-related HCV epidemics, needing to scale-up testing/case-finding initiatives.

It is estimated that of 50,000 persons in Scotland (1% of the county's population), infected with the hepatitis C virus (HCV), around 90% injected drugs. This paper reviews data on the prevalence and incidence of HCV, and the methods used to generate such information, among injecting drug users (IDUs), in Scotland. The prevalence estimate for HCV among IDUs in Scotland as a whole (44% in 2000), is comparable with those observed in many European countries. Incidence rates ranged from 11.9 to 28.4/100 person-years. The data have shaped policy to prevent infection among IDUs and have informed predictions of the number of HCV-infected IDUs who will likely progress to, and require treatment and care for, severe HCV-related liver disease. Although harm reduction interventions, in particular needle and syringe exchanges and methadone maintenance therapy, reduced the transmission of HCV among IDUs during the early to mid-1990s, incidence in many parts of the country remains high. The prevention of HCV among IDUs continues to be one of Scotland's major public health challenges.