Clinical Characteristics and Impact of Clostridium difficile Infection during Treatment of Rifampicin-Susceptible Pulmonary Tuberculosis.

Background: Anti-tuberculosis (TB) treatment, although infrequently associated with Clostridium difficile infection (CDI), necessitates updated research on the incidence and clinical features of CDI among TB patients, especially as the demographic of older TB patients in South Korea is growing.

Methods: A total of 168 patients with rifampin-susceptible pulmonary TB were enrolled in this study. Initial clinical features of the CDI-suspected group, risk factors for CDI, the primary outcome of all-cause mortality, and secondary outcomes, including delayed conversion of acid-fast bacillus (AFB) smear and culture, were analyzed.

Results: The incidence rate of CDI among TB patients was 15.0 cases per 10,000 patient- days. Among initial features associated with TB-related CDI, patients exhibiting diarrhea of Bristol stool scale type 7 for more than 2 days were more likely to receive a CDI diagnosis. Old age and hypoalbuminemia were significant risk factors for CDI occurrence. In the primary outcome analysis, CDI was associated with a 4.63-fold increase in all-cause mortality according to the unadjusted analysis. However, this association dissipated in the adjusted analysis. Older age, underlying respiratory disease, and pneumonia at baseline were strong predictors of all-cause mortality. No significant factors were detected in the analysis of delayed AFB smear and culture conversion.

Conclusion: Despite the lack of an independent association between CDI and all-cause mortality among TB patients, monitoring older adults with undernutrition and persistent diarrhea for CDI is crucial.