Risk factors for recurrence of pulmonary tuberculosis in properly treated patientsand declared healed

Despite the national tuberculosis control program in Tunisia, and the efforts made by the health authorities, a relapse-free cure for pulmonary tuberculosis (TB) remains elusive and not always guaranteed. This study aimed to identify risk factors for pulmonary tuberculosis recurrence among adequately treated patients who had been declared healed.

We collected records of patients treated for the first episode of TB in the pulmonology department of Charles Nicolle Hospital of Tunis between 2013 and 2021. Every patient had at least one year follow-up after the end of treatment. Two groups were identified: patients with TB recurrence (G1) and patients without TB recurrence (G0).

We analyzed data of 140 patients treated for TB, and 12 patients had a TB recurrence (G1: 8.6%). G1 patients were significantly older (45 years vs 42 years, p=0.013). There was no significant difference between groups in terms of gender-ratio (p0.05), tobacco intoxication (p0.05), substance abuse (p0.05), nor comorbidities (p0.05). However, G1 patients had a more frequent history of incarceration (p0.001). Time to consult and time to bacteriological confirmation of TB didn't differ between groups. Evolution was characterized by a slower clinical improvement (p=0.006) and a longer time of bacilloscopic negativity in G1 (p=0.048). Multivariate analysis showed that the delay in clinical improvement beyond 30 days (OR=9.79; 95% CI=1.77-54.05; p=0.009) and the delay in bacilloscopic negativity (OR=4.93; 95% CI=1.06-22.92; p=0.042), were independent risk factors associated with TB recurrence.

Pulmonary TB recurrence concerns mainly patients with a delayed time to bacilloscopic negativity and a slower clinical improvement, particularly beyond 30 days. These at-risk patients require specific follow-up to prevent this complication.