Background People with Diabetes Mellitus (DM) are at increased risk for TB and those who have latent TB infection (LTBI) might be indicated for TB preventive therapy. We examined the prevalence and determinants of LTBI among people with DM as part of the PROTID project in Uganda and Tanzania.

Methods A total of 2005 participants with DM were screened for LTBI at four sites in Uganda and Tanzania. LTBI was diagnosed using the tuberculin skin test (TST) with a cutoff of 10mm and or a positive QuantiFERON-TB plus (QFT-plus) after excluding ATB.

Results The overall prevalence of LTBI was high at 56.3% (lowest at 35.1% in Moshi, Tanzania, and highest at 77% in Kampala, Uganda). 780/2005 (38.9%) had a positive TST, 862 (43.0%) had a positive QFT-plus, and 515 (25.7%) had both a positive TST and QFT-plus. There was a good agreement of 72% (k=0.42; 95% CI: 0.38–0.46) between the two tests. On multivariable analysis, those aged between 36–45 [AOR=2.38 (CI: 1.44–3.92)]; 46–55 [AOR=1.98 (CI: 1.26–3.13)]; and 55 years and above [AOR=1.48 (CI: 0.95–2.29)]; previous TB [AOR=1.85(CI:1.15–2.99, p=0.01)], contacts with TB disease [AOR=1.51(CI:1.16–1.96)] were associated with increased odds of LTBI positivity while Female gender [AOR=0.59(CI: 0.48–0.73), p<0.001] and HIV positivity [AOR=0.66(CI:0.47–0.93), p=0.02] were statistically not associated with LTBI positivity. Overweight and obese DM patients had increased odds of LTBI [AOR=1.85 (1.02–3.35) p=0.04 and AOR=2.18 (1.19–3.97) p=0.01] respectively. Known factors such as current BCG scar, smoking, or alcohol use were not associated with LTBI in this population.

Conclusion People with DM in East Africa are at a high risk of LTBI. Early detection and treatment of LTBI in this population could help prevent the progression to active TB and reduce morbidity and mortality associated with TB in people with DM.

Funding: EDCTP