Postviral syndrome--how can a diagnosis be made? A study of patients undergoing a Monospot test.

Eighty-nine of 150 patients having a Monospot test filled out a questionnaire about their illness, and the General Health Questionnaire. They completed a follow-up questionnaire 6 months later. Twelve (8%) had a positive Monospot. Twenty-eight of 83 serum samples tested (34%) were positive for VP1 enteroviral antigen. Forty of the patients had a self limiting illness, 13 had a definite diagnosis (excepting glandular fever), 14 had a possible postviral syndrome, 10 had recurrent sore throats/flu, and 12 had a chronic non-specific illness. Patients with a specific diagnosis were less likely to complain of aching muscles/joints, sore throat, tiredness or loss of concentration. Their GHQ scores were lower, although this just failed to reach significance (P = 0.08), and they scored significantly lower on the somatic symptoms subscale (P = 0.022). Overall 72% scored above the GHQ threshold for 'psychological caseness' which is higher than in other studies. Sixty-five per cent of the sample questioned at 6 months felt that their illness started with a viral infection. The methodological problems involved in making a diagnosis of postviral syndrome are discussed.