Predictors of Epstein-Barr virus serostatus in young people in England

Abstract

BackgroundEpstein-Barr virus (EBV) is an important human pathogen which causes lifelong infection of > 90% people globally and is linked to infectious mononucleosis (arising from infection in the later teenage years) and several types of cancer. Vaccines against EBV are in development. In order to determine the most cost-effective public health strategy for vaccine deployment, setting-specific data on the age at EBV acquisition and risk factors for early infection are required. Such data are also important to inform mathematical models of EBV transmission that can determine the required target product profile of vaccine characteristics. We thus aimed to examine risk factors for EBV infection in young people in England, in order to improve our understanding of EBV epidemiology and guide future vaccination strategies.MethodsThe Health Survey for England (HSE) is an annual, cross-sectional representative survey of households in England during which data are collected via questionnaires and blood samples. We randomly selected individuals who participated in the HSE 2002, aiming for 25 participants of each sex in each single year age group from 11 to 24 years. Stored samples were tested for EBV and cytomegalovirus (CMV) antibodies. We undertook descriptive and regression analyses of EBV seroprevalence and risk factors for infection.ResultsDemographic data and serostatus were available for 732 individuals. EBV seroprevalence was strongly associated with age, increasing from 60.4% in 11–14 year olds throughout adolescence (68.6% in 15–18 year olds) and stabilising by early adulthood (93.0% in those aged 22–24 years). In univariable and multivariable logistic regression models, ethnicity was associated with serostatus (adjusted odds ratio for seropositivity among individuals of other ethnicity versus white individuals 2.33 [95% confidence interval 1.13–4.78]). Smoking was less strongly associated with EBV seropositivity.ConclusionsBy the age of 11 years, EBV infection is present in over half the population, although age is not the only factor associated with serostatus. Knowledge of the distribution of infection in the UK population is critical for determining future vaccination policies, e.g. comparing general versus selectively targeted vaccination strategies.

Factors associated with cytomegalovirus serostatus in young people in England: a cross-sectional study

“…CMV and EBV serostatus were positively associated in univariable analyses, and when the multivariable analysis was restricted to adults, but not in the multivariable model which also included children aged 11–15 years. As discussed in our previous paper [ 20 ], both CMV and EBV are associated with increasing age, however EBV increases more rapidly during adolescence than CMV. Thus, in a whole-cohort model adjusting for age, this association may not be visible.…”

“…Thus, in a whole-cohort model adjusting for age, this association may not be visible. As the associations between age and both CMV and EBV [ 20 ] are less strong in adults, it is possible that there was enough of a residual effect that the association between CMV and EBV could be detected in the adults-only model. Given the cross-sectional nature of our study, the relative temporality of the two infections could not be assessed.…”

“…The methods have been described previously [ 25 ]. As part of a larger study investigating Epstein-Barr virus infection and transmission [ 20 , 26 ], we used data from randomly selected participants in the 2002 HSE, aiming for 25 male and 25 female participants in each single-year age group from 11 to 24 years.…”

“…Results were presented in relative units (RU/mL) using the following thresholds; samples of <16RU/mL were classed as negative, ≤16 to <22RU/mL were borderline, and ≥ 22RU/mL were positive. For the analyses presented here, borderline results (CMV n = 1, EBV n = 5) were considered seropositive [ 20 ].…”

“…Lower income and education levels, and ethnicities other than white, have been associated with earlier age at CMV infection [ 18 ]. CMV infection is also correlated with EBV infection [ 19 , 20 ]. Socioeconomic status is strongly correlated with CMV infection; the reasons for this could include larger family size [ 21 ], or have been hypothesised to be a result of stress induced by low socioeconomic status contributing to the down-regulation of the immune system and increased susceptibility to infection [ 18 ].…”