Empiric antituberculosis treatment: benefits for earlier diagnosis and treatment of tuberculosis

Abstract Setting: Tuberculosis may be diagnosed too late, especially in HIV-infected patients, with consequences on bacillus transmission and survival. Empiric antibuberculosis treatment (EATT) may be started before diagnosis of tuberculosis is confirmed. As rifampicin is a broad spectrum antibiotic, EATT including rifampicin may be effective in infections other than tuberculosis, leading to misdiagnosis. Objective: To define the efficiency criteria of EATT with or without rifampicin. Design: Between 1988 and 1991, 20 febrile patients with suspected tuberculosis (including 15 who were HIV-positive) were started on EATT in the absence of bacteriological or histological proof of tuberculosis. 10 patients (50%) received a 4-drug non-specific EATT including rifampicin, isoniazid, pyrazinamide and ethambutol, and 10 (50%) received a 3-drug specific EATT without rifampicin. Results: In 10 patients (50%), the diagnosis of tuberculosis was confirmed by positive cultures within a mean of 32 days (15–57 days) after the beginning of EATT (group TB 1). Of the 10 patients whose cultures remained negative, 4 (20%) became afebrile and showed improvement under EATT (group TB 2), and 6 (30%) remained febrile and did not improve (group No TB). Patients from groups TB l and TB 2 became afebrile within a mean of 11 days (1–54 days). This delay was not different between patients receiving specific or non-specific EATT. In patients receiving specific EATT, rifampicin was added to the initial 3-drug treatment after resolution of fever. Conclusion: EATT appears to be a useful method for rapid presumptive diagnosis and treatment of tuberculosis.