Heteroduplex mobility assay was used to identify variants of varicella-zoster virus (VZV) circulating in the United Kingdom and elsewhere. Forty variable positions were identified. Sixteen substitutions were non-synonymous, resulting in an amino acid change, the majority of which were clustered within surface expressed proteins. Phylogenetic analysis distinguished at least three major clades (strains A, B, C) supported by significant bootstrap values. Apart from the United Kingdom and Brazil where all three strains were found, genotypes appeared to be closely associated with the geographical region in which they were sampled. Allelic co-segregation of widely spaced single nucleotide polymorphisms (SNPs) confirmed the genetic stability of the VZV. Recombination rates were difficult to calculate because of the low intra genotypic variation. However, one haplotype originating from Brazil is most parsimoniously explained as a recombinant between A and C strains, which co-occur in the region. Two further UK strains appeared to be recombinants between groups B and C.

Of 75 varicella-zoster virus (VZV) isolates obtained from patients in Africa, Asia, and the Far East, 74 (98.6%) were found to be positive for a BglI restriction site in gene 54. By contrast, <22% of strains from patients in the United Kingdom and in North and South America were positive for the BglI restriction site. Viruses positive for BglI were significantly more common in zoster occurring in patients of nonwhite origin (P<.05). Irrespective of the country in which the sample was obtained, 98% of strains positive for BglI clustered within a single phylogenetic group, which we termed "group A"; the exception was 1 strain that appeared to be recombinant genotype C/A. We used the BglI site to examine both the spread of type A viruses in the United Kingdom and the patterns of VZV infections within persons from different ethnic groups who grew up in the United Kingdom or abroad.

The incidence of post-herpetic neuralgia following shingles and the factors that are known to predict it were examined in a prospective observational community study of patients with acute shingles presenting to their family doctors. The detection of viral DNA in the blood at presentation as a prognostic indicator for pain was also evaluated. Patients were followed for one year and the persistence of pain following rash assessed. Among 165 patients who had completed 6 months, and 139 one-year follow-up, the prevalence of post herpetic neuralgia was 30% at 6 weeks 27% at 12 weeks, 15.9% at 6 months, and 9% at one year. Age and severity of pain were significantly associated with the persistence of pain beyond 3 months. Viremia at presentation was detected in 66% of patients and was significantly associated with the presence of pain at six months or beyond. Antiviral agents were administered to only 50% of those at highest risk of post-herpetic neuralgia (PHN) mainly because of presentation longer than 72 hours after the onset of rash. Few patients were prescribed the more potent prodrugs, Valaciclovir and Famciclovir. In conclusion, treatment of acute shingles in this observational community-based study was suboptimal in 50% of cases. More accurate prediction of which subset of elderly patients are most at risk of PHN may enable targeted prescribing of the most potent drugs to those most likely to benefit.

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We compared two commercial molecular assays (the Murex Hybrid Capture CMV DNA assay [HCA], version 2, and the Roche Amplicor plasma PCR assay) with a standard shell vial assay in detecting and predicting cytomegalovirus (CMV) disease in a group of renal transplant patients and assessed the role of viral load measurements (using the HCA) in their management. The sensitivity of the HCA and Amplicor assay in terms of disease detection was 100%, compared to 71% for the shell vial assay. Both the HCA and the PCR assay detected all cases of disease, at medians of 11 and 12.5 days before the onset of symptoms, respectively. Significantly higher viral loads were detected in those patients with symptoms (7.9 × 105 copies/ml) than in patients without symptoms (7.9 × 104 copies/ml;P < 0.0001). There was also a trend towards higher viral loads in those patients with primary infections (7.8 × 105 copies/ml) than in those patients with reactivations of CMV disease or reinfections. Successful treatment with ganciclovir was associated with a >90% reduction in viral load. Both of these new assays are sensitive and easy to use. A comparison of accurate quantitation is also useful in monitoring responses to antiviral therapy.

We evaluated a cytomegalovirus (CMV) 24-hour shell vial assay (SVA), the Murex Hybrid Capture CMV DNA assay (HCA), and a CMV plasma PCR for the detection of CMV viremia in renal and bone marrow transplant recipients and human immunodeficiency virus-infected patients. CMV viremia was detected by at least one method in 125 of 317 evaluable samples (39.4%) from 78 patients and was detected in 19.8% of samples by SVA, 26.8% by HCA, and 32.2% by plasma PCR. There was moderate to substantial agreement between the results of the different tests (kappa coefficient = 0.415 to 0.631). However, HCA and plasma PCR were significantly more sensitive than SVA (P = 0.001 and P < 0.0001, respectively; McNemar’s test), and plasma PCR was more sensitive than HCA (P = 0.031; McNemar’s test). HCA and plasma PCR were more consistently positive than SVA during viremic episodes (P = 0.0002 and P < 0.0001, respectively; McNemar’s test). The use of HCA or plasma PCR may therefore improve the diagnosis and management of CMV disease in susceptible patient groups.