The changing epidemiology of infectious mononucleosis?

Abstract

Infectious mononucleosis is an acute and self-limited infection of the lymphatic system caused in over 90% of cases by a primary infection with Epstein-Barr virus (EBV), a member of the herpes virus group [1]. Infection during childhood is usually subclinical, whereas infection of adults results in infectious mononucleosis in 30± 75% of cases and can prove severe [2,3]. EBV infection in childhood is associated with low socioeconomic status, poor hygiene and crowding so that improved housing and decreasing family sizes may have resulted in a change in the epidemiology of EBV and therefore infectious mononucleosis [4,5]. To investigate this possibility we reviewed historical data of general practitioner (GP) consultations and hospitalisations in England and Wales over thirty years. Data on age-specific consultation rates for infectious mononucleosis in England and Wales were obtained from the Royal College of General Practitioners (RCGP) sentinel surveillance reports [6]. The surveillance programme is based on clinical diagnoses and uses a sample of practitioners throughout England and Wales which currently covers a population of over 600,000. Data for the calendar years 1989±1998 were extracted from the Hospitalisation Episode Statistics (HES, Department of Health) database that records every inpatient admission to National Health Service hospitals in England. Cases of infectious mononucleosis were identified using the International Classification Disease Codes 075* (ICD-9 up until 1995) and B27* (ICD-10 from 1996 onwards). The ICD-9 code 075* did not distinguish between different viral causes of infectious mononucleosis. For consistency, from 1996 onwards the ICD-10 code B27* was used which included infectious mononucleosis from EBV, cytomegalovirus (CMV), other viral causes and unspecified types. However, in practice