Effect of adequate long-term chemotherapy on relapse in pulmonary tuberculosis

This paper is a review of patients with pulmonary tuberculosis at the Toronto Hospital, Weston, “adequately” treated and discharged by medical consent between January 1954 and June 1956. It is not an account of a study carefully planned in advance, but a retrospective report of results obtained by treatment then in vogue (namely long-term chemotherapy with at least two drugs, but usually three, for a period of one year, and surgical measures where these seemed to be indicated).

The total number of all patients discharged during this time was 1,734. Of these, 850 were considered suitable for review in that they satisfied our criteria of adequate treatment. Six hundred and forty-eight were actually traced and of these 20 have relapsed to date (June 1958); 5 more were re-admitted because of recurrence of symptoms of pulmonary disease, but reactivation could not be established; 6 patients died of causes other than tuberculosis. The relapse rate is thus 3·1 per cent.

The relapse cases were studied in detail. The ages ranged from 22 to 67 years and 10 of the 20 patients were aged 40 years or less at time of relapse. Eight were females and 12 were male patients.

Sensitivity to drugs was complete in 11, unreported in 3, and in 2 patients tubercle bacilli were not cultured. Partial resistance only to one drug was encountered in the remaining 4 patients. Only one of the 20 patients had a resection (lobectomy) performed, but 3 had thoracoplasty as part of their treatment before relapse. It is of interest that in 4 patients resection was considered necessary but was not done for various reasons.

This study seems to confirm tentative conclusions previously held by us regarding predisposition to relapse after treatment.