Examination of latent tuberculosis infection treatment status

OBJECTIVE: To clarify factors involved in the refusal or discontinuation of treatment for latent tuberculosis infection (LTBI), we reviewed LTBI treatment. METHOD: The subjects were 193 patients for whom LTBI treatment was indicated on a family contact investigation in 2006. We examined the subjects' backgrounds and reasons for treatment refusal or discontinuation. In addition, we investigated the incidence of the onset of tuberculosis within 2 years after the final contact with the source of infection. RESULTS: i) Patient background: The state of treatment could be evaluated in 185 patients. Of these, drug therapy was completed in 138 (75%), whereas 47 (25%) refused or discontinued treatment. The mean ages of the former and latter were 21.0 and 26.2 years, respectively, showing a significant difference. Concerning the state of contact, 9 (8%) of 114 patients who had lived with and 12 (17%) of 71 who had lived apart from the source of infection refused treatment, showing a significant difference. ii) Onset within 2 years: We analyzed 180 patients for whom follow-up was possible. Drug therapy was completed in 137 patients. No patient developed tuberculosis onset. On the other hand, drug therapy was not completed in 43 patients, and 6 (14%) developed tuberculosis onset. iii) The reasons were investigated in 47 patients who did not complete drug therapy. There were 15 episodes associated with side effects, followed by 14 related to personal circumstances, such as being busy, disliking medicines, and the absence of confidence regarding the completion of drug therapy, and 6 associated with either insufficient explanations regarding the diagnosis or an absence of symptoms. CONCLUSION: Treatment refusal/discontinuation was more frequent in the more advanced age groups and patients who had lived apart from the source of infection. It may therefore be necessary to more closely explain the importance of treatment to these patients. Most reasons for treatment refusal/discontinuation were associated with side effects or insufficient explanations, suggesting the necessity of providing sufficient information to aid in patient understanding.