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WHEN IS PULMONARY TUBERCULOSIS CURED?
1462
Letters
to
the Editor
WHEN IS PULMONARY TUBERCULOSIS CURED?
SlR,—Your May 22 editorial is based on my definition of successful treatment of pulmonary tuberculosis which requires that "the patient’s sputum be rendered negative by both smear and culture at least six months prior to completion of therapy and remain negative for life". This definition has provoked widespread controversy, both in Europe and America, since, as you pointed out, "such a strict definition invalidates nearly all existing" trials of short course chemotherapy. These studies allow an unlimited number of positive smears and some positive cultures in the final month of treatment and during the post-therapy period without regarding the patient as a treatment failure or relapse. When the more stringent definition is applied, the results of these trials
change dramatically. 1-5 My claims 1-6 that almost all trials of short course chemotherapy are either invalid or wrongly interpreted, because of the loose definitions on which they are based, have upset the designers of these studies. I am not surprised that they feel compelled to discredit my definition by branding it as "flawed" and "unconventional", but in response to many lectures and publications I have yet to clinician who does not agree with me. You state that "most clinicians will be content merely to watch an otherwise well patient who produces an isolated positive sputum after adequate chemotherapy, although the temptation to re-treat will become stronger with each successive positive culture". In contradiction, you also state that "such isolated positive cultures certainly make it difficult to pronounce the patient cured". My colleagues agree only with the latter statement. They regard a positive post-treatment culture as evidence of inadequate treatment or relapse or failure to cure and immediately reinstitute therapy. They are not "content merely to watch" such patients and do not consider further treatment as something to be encounter a
Letters
to
the Editor
WHEN IS PULMONARY TUBERCULOSIS CURED?
SlR,—Your May 22 editorial is based on my definition of successful treatment of pulmonary tuberculosis which requires that "the patient’s sputum be rendered negative by both smear and culture at least six months prior to completion of therapy and remain negative for life". This definition has provoked widespread controversy, both in Europe and America, since, as you pointed out, "such a strict definition invalidates nearly all existing" trials of short course chemotherapy. These studies allow an unlimited number of positive smears and some positive cultures in the final month of treatment and during the post-therapy period without regarding the patient as a treatment failure or relapse. When the more stringent definition is applied, the results of these trials
change dramatically. 1-5 My claims 1-6 that almost all trials of short course chemotherapy are either invalid or wrongly interpreted, because of the loose definitions on which they are based, have upset the designers of these studies. I am not surprised that they feel compelled to discredit my definition by branding it as "flawed" and "unconventional", but in response to many lectures and publications I have yet to clinician who does not agree with me. You state that "most clinicians will be content merely to watch an otherwise well patient who produces an isolated positive sputum after adequate chemotherapy, although the temptation to re-treat will become stronger with each successive positive culture". In contradiction, you also state that "such isolated positive cultures certainly make it difficult to pronounce the patient cured". My colleagues agree only with the latter statement. They regard a positive post-treatment culture as evidence of inadequate treatment or relapse or failure to cure and immediately reinstitute therapy. They are not "content merely to watch" such patients and do not consider further treatment as something to be encounter a