High Prevalence of Mycobacterium Tuberculosis Infection and Disease in Children and Adolescents with Type 1 Diabetes Mellitus

Setting: Western Cape Province, South Africa.

Objectives: To describe the prevalence of tuberculosis (TB) infection and disease in children with type 1 diabetes and to investigate the association between glycaemic control and prevalence of TB infection and disease.

Design: Cross-sectional hospital-based study conducted at two public referral hospitals. All children and adolescents (aged <21 years) with type 1 diabetes underwent a Mantoux tuberculin skin test (>or=10 mm classified as Mycobacterium tuberculosis infection), measurement of glycosylated haemoglobin and a chest radiograph. Patients with symptoms suggestive of TB were investigated using mycobacterial culture. Radiologically and/or bacteriologically confirmed disease was classified as TB disease.

Results: Of 291 eligible patients, 258 (88.7%) were included (58% female). The prevalence of M. tuberculosis infection was 29.8% (95%CI 24.2-35.4); nine patients were diagnosed with prevalent TB disease (point prevalence disease 3488 per 100,000 population). Poor glycaemic control (hazard ratio 1.39, 95%CI 1.18-1.63 per unit increase in glycated haemoglobin [HbA1c]) and contact with a TB source case (P = 0.0011) was associated with prevalent TB disease.

Conclusions: There is a high prevalence of TB disease in diabetic children and adolescents in this setting. Routine TB screening of children with type 1 diabetes may be indicated in settings highly endemic for TB. Preventive treatment should be considered for diabetic children with proof of TB exposure and/or infection.