Incomplete contact investigation and risk of developing TB among healthcare professionals.

BACKGROUND

Data on the impact of incomplete contact investigation on TB incidence among healthcare professionals (HCPs) after TB exposure are limited.

METHODS

This was a prospective cohort study with 2-year follow-up among Thai HCPs exposed to TB to determine TB incidences and factors associated with TB development.

RESULTS

Of the 398 HCPs with TB exposure, 367 (92%) participated in the study; 342 HCPs were included in the final analysis; 311 participated in contact investigations; 303 underwent chest X-ray; 252 completed baseline TB and latent TB infection screening using tuberculin skin test (TST); 210 had negative baseline TST; and 45 completed follow-up tests at 3 months. Altogether, 20 HCPs developed TB (2.92/100 person-years). TB incidences in HCPs not participating in or not completing the investigation at any step were higher than in those who completed the evaluation (11.29 and 2.90, respectively, vs. 0/100 person-years; P < 0.05). No participation in contact investigation and no baseline chest X-ray were independent factors associated with TB development (adjusted odds ratio [aOR] 6.7; P < 0.001 and aOR 8.9; P = 0.01, respectively).

CONCLUSION

Study findings indicate increased risks of TB development among HCPs not undergoing or not completing contact investigations and underscore the need for interventions to improve contact investigation participation and completeness.