Tuberculosis prevalence and associated factors among persons with diabetes mellitus after intensified case finding in three West African countries

Background: To determine the prevalence of tuberculosis (TB) and associated factors in persons with diabetes mellitus (DM) in Benin, Guinea and Senegal. Patients and Method: A cross-sectional study was conducted in the largest DM center in each country. Participants systematically underwent clinical screening and chest radiography. Participants who were symptomatic or with abnormal radiography underwent bacteriological investigations (sputum smear, Xpert MTB/RIF and culture) on sputum. Participants with no TB at enrolment were re-examined for TB six months later. Logistic regression was performed to identify factors associated with TB. Results: There were 5,870 DM patients: 1,881 (32.0%) in Benin, 1,912 (32.6%) in Guinea and 2,077 (35.4%) in Senegal. Out of these, 114 had bacteriologically-confirmed TB, giving a pooled prevalence of 1.9% (95%CI=1.6-2.3). TB prevalence was 0.5% (95%CI=0.3-1.0), 2.4% (95%CI=1.8-3.2) and 2.8% (95%CI=2.2-3.6), respectively, in Benin, Guinea and Senegal. Factors associated with an increased odds of TB diagnosis were a usual residence in Guinea (aOR=2.62;95%CI=1.19-5.77; p=0.016) or in Senegal (aOR=3.73;95%CI=1.85-7.51; p<0.001), the age group of 35-49 years (aOR=2.30;95%CI=1.11-4.79; p=0.025), underweight (aOR=7.34;95%CI=4.65-11.57; p<0.001) and close contact with a TB case (aOR=2.27;95%CI=1.37-3.76; p=0.002). Obesity was associated with lower odds of TB (aOR=0.20; 95%CI=0.06-0.65; p=0.008). Conclusion: TB is prevalent among DM patients in Benin, Guinea and Senegal and higher than among the general population. The findings support the need for intensified case finding in DM patients in order to ensure systematic early detection of TB during the routine consultation process.