Miller E, Gibs T, Parker C, em et al /em
Miller E, Gibs T, Parker C, em et al /em . in recent years, with an upward shift in age distribution. Monitoring of cases reported by spotter general practices has shown a significant increase in both the absolute number and the proportion of cases in those over 14 years over HIV-1 inhibitor-3 the past 20 years.1 A review of notifications in a Scottish health region for 1988C92 showed that 24% of cases were in patients aged 15 or over.2 The epidemiology of VZV has HIV-1 inhibitor-3 important implications for future vaccine strategies. This study of age related VZV seroprevalence over the past 25 years was undertaken to ascertain whether the increase in reported cases of chickenpox in adults results from the decrease in numbers of immune adults as reflected by a switch in seroprevalence. blockquote class=”pullquote” The epidemiology of VZV has important implications for future vaccine strategies /blockquote SUBJECTS AND METHODS The sera for our study were drawn from a series of independent cross sections of anonymised patients divided HIV-1 inhibitor-3 into the following age groups: 1C4, 5C9, 10C19, 20C29, and 30C39 years, from whom blood samples were submitted for routine assessments during the months of June and July each year over the past 25 years and an aliquot stored at ?20C. An upper age limit for screening of 39 years was chosen because 95% seroprevalence rates in over 40 12 months olds3 would not have allowed us to detect changes in seroprevalence with the small numbers of samples available for screening. The children under 10 years aged were subdivided to distinguish between preschool and school age children. Samples from infants aged less than 1 year were excluded because it would not be possible to distinguish passively acquired maternal antibody from that resulting from infection. As far as possible Rabbit Polyclonal to PBOV1 within the limitations of available sera, specimens were tested from each age group at four yearly intervals with substitutions from preceding or following years if necessary. A total of 1530 sera were tested by a commercially available VZV IgG assay (Bio-Stat Diagnostic). Samples giving an equivocal result by the manufacturer’s criteria were repeated. Those giving a repeat equivocal result were excluded from your analysis. RESULTS Four samples giving a repeated equivocal result by the manufacturer’s criteria were excluded from your analysis. Table 1?1 shows the seroprevalence of VZV, stratified by age cohort, for each of the sampling years. For all those years the seropositive rate in subjects older than 20 years exceeded 90%. Table 1 Age related varicella zoster computer virus antibody prevalence thead 12 months of surveyAge of cohort (years)1966197019741978198419881992 /thead 1C41/14 (7)2/46 (4)11/54 (20)3/12 (25)5/21 (24)8/34 (24)37/73 (51)5C918/32 (56)24/37 (65)23/43 (53)9/30 (30)24/43 (56)9/26 (35)23/36 (64)10C194/6 (67)40/40 (100)23/28 (83)37/47 (79)31/39 (79)51/58 (88)44/46 (96)20C2948/49 (98)66/67 (99)45/48 (94)43/48 (90)50/55 (91)49/53 (92)30C3931/31 (100)41/45 (91)46/47 (98)22/30 (73)49/52 (94)52/54 (96) Open in a separate window Figures in parenthesis are percentages. We analysed the data in table 1?1 by logistic regression, with the aim of investigating the evidence for changes in incidence over the period. If there were no changes in incidence, one would expect the prevalence to remain the same within age groups. Therefore, we estimated the styles in prevalence over time within each age group. Our model confirms the fact that prevalence increases significantly with age, at least to age 19, representing the acquisition of HIV-1 inhibitor-3 contamination (p 0.0001). We found significant differences in prevalence styles over time between age groups (p 0.0001). These differences are primarily attributable to a sharp increase in prevalence in the 1C4 12 months age group (odds ratio (OR), 1.09; 95% confidence interval (CI), 1.05 to 1 1.13). Other changes are less HIV-1 inhibitor-3 obvious. Prevalence in the 20C29 12 months age group declined marginally (OR, 0.93; 95% CI, 0.88 to 1 1.00) with no significant changes in other age groups. Conversation A previous study by Joseph and Noah4 experienced reported an increase in the incidence.