ChuanChin Huang, ScD

Pronouns

He/Him/His

Job Title

Associate Epidemiologist

Academic Rank

Instructor

Department

Medicine

Authors

CC Huang, ML Lecca, R Calderón, C Contreras, R Yataco, Z Zhang, M Murray

Principal Investigator

ChuanChin Huang

Research Category: Allergy, Immunology, Inflammation, and Infectious Diseases

Tags

The impact of Diabetes mellitus on transmission dynamics of tuberculosis

Scientific Abstract

Diabetes mellitus (DM) is a known risk factor of Tuberculosis (TB). The global increase in DM is recognized as an emerging risk and challenge to slow gains in TB control. While previous studies have consistently shown that individuals with DM have a three-fold increased risk of developing TB, it is unclear whether DM modifies the transmissibility of TB patients. Between 2009 and 2012, we enrolled 3,109 microbiologically-confirmed pulmonary index TB patients and their 12,767 household contacts (HHCs) in Lima, Peru. During 12-months follow-up, HHCs of a diabetic TB patient were less likely to develop incident tuberculosis compared to those exposed to a non-diabetic one (aHR=0.33 [0.13-0.86]). Using Mycobacterium tuberculosis whole genome sequences and the time of TB diagnosis of the index patients, we identified 1,273 transmitter-receiver patient pairs. Compared to the marginal distribution of diabetes status obtained by randomly picking two patients, the transmitters had a reduced possibility of being diabetic (aRR=0.67 [0.48-0.92]), while the receivers had an increased possibility (aRR=1.38 [1.14-1.92]). Our findings demonstrate that diabetic TB patients are less likely to transmit TB than non-diabetic TB patients. Our results suggest that the potential impact of diabetes on the tuberculosis epidemic trajectory may be more complicated than previously understood.

Lay Abstract

Individuals with diabetes mellitus (DM) are more likely to develop tuberculosis (TB). Since diabetic TB patients are more likely to have an increased bacterial load in the sputum than nondiabetic TB patients, most TB researchers and pulmonary doctors surmise that diabetic TB patients are more likely to transmit TB than non-diabetic TB patients. In our study, we enrolled 3,109 TB patients and their 12,767 household contacts (HHCs) in Lima, Peru. During 12-months follow-up, the HHCs of diabetic TB patients were less likely to develop TB compared to HHCs of non-diabetic patients. Using Mycobacterium tuberculosis whole genome sequences and the time of TB diagnosis of the TB patients, we identified 1,273 direct transmission (transmitter-recipient) patient pairs. We found that transmitters had a reduced possibility of being diabetic, while the receivers had an increased possibility. These results indicate that while individuals with DM were more likely to develop TB, they may have reduced infectiousness after developing the disease. Our findings suggest that the potential impact of diabetes on the tuberculosis epidemic trajectory may be more complicated than previously realized.

Clinical Implications

We found that while individuals with diabetes mellitus are more likely to develop TB, they may have reduced infectiousness after developing the disease. Our findings challenge the current understanding about the impact of diabetes on the tuberculosis epidemic trajectory.