Incidence, risk and prognosis of acute and chronic fatigue syndromes and psychiatric disorders after glandular fever

Background The role of viruses in the aetiology of both chronic fatigue syn drome (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 (interquartil e 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 gland ular fever compared with 0-6% following an ordinary URTI, with relative ris ks 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 conservativ e 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 depress ive disorder were triggered by infection, especially the Epstein - Barr vir us, but lasted a median of only three weeks. No psychiatric disorder was si gnificantly more prevalent six months after onset than before. Conclusions 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 las t more than a month.