Longitudinal Symptom Transitions Predict Incident Tuberculosis Risk in Serial Active Case Finding.

Tuberculosis (TB) screening often relies on cross-sectional symptom assessment. To determine the added value of longitudinal symptom monitoring, we conducted a prospective cohort study among 2282 incarcerated men in Brazil. Every 4 months, participants were assessed for symptoms and incident TB (Xpert or culture positive). Compared with remaining asymptomatic, developing symptoms was associated with higher TB risk (aRR 2.31; 95% CI 1.55-3.43), strongest among those with prior radiographic abnormalities (aRR 2.49; 95% CI 1.56-3.97), while remaining symptomatic was not associated (aRR 1.27; 95% CI .72-2.24). Longitudinal symptom monitoring may enhance TB screening in high-risk settings, particularly in complement with radiography.