BACKGROUND: The role of viruses in the aetiology of both chronic
fatigue syndrome (CFS) and depressive illness is uncertain.
METHOD: A prospective cohort study of 250 primary care
patients, presenting with glandular fever or an ordinary upper
respiratory tract infection (URTI).
RESULTS: The incidence of
an acute fatigue syndrome was 47% at onset, after glandular
fever, compared with 20% with an ordinary URTI (relative risk
2.3, 95% CI 1.3-4.1). The acute fatigue syndrome lasted a
median (interquartile range) of eight weeks (4-16) after
glandular fever, but only three weeks (2-4) after an URTI. The
prevalence of CFS was 9-22% six months after glandular fever,
compared with 0-6% following an ordinary URTI, with relative
risks of 2.7-5.1. The most conservative measure of the
incidence of CFS was 9% after glandular fever, compared with
no cases after an URTI. A conservative estimate is that
glandular fever accounts for 3113 (95% CI 1698-4528) new cases
of CFS per annum in England and Wales. New episodes of major
depressive disorder were triggered by infection, especially
the Epstein-Barr virus, but lasted a median of only three
weeks. No psychiatric disorder was significantly more
prevalent six months after onset than before.
Glandular fever is a significant risk factor for both acute
and chronic fatigue syndromes. Transient new major depressive
disorders occur close to onset, but are not related to any
particular infection if they last more than a month.