Rapid Increases in Observed Incidence and Prevalence of Type 1 Diabetes in Children and Youth in Mali, 2007-2016

Aims: Determine incidence, prevalence and mortality of Type 1 diabetes (T1D) in children and youth <25 years (y) in Mali during the first 10 years of the Santé Diabète/Life for a Child program.

Methods: Data were collected from the prospective program register. Diagnosis of T1D was clinical, based on presentation, clinical features, immediate requirement for insulin, and no suggestion of other diabetes types.

Results: Total of 460 cases were diagnosed with T1D <25 years in 2007-2016. Male-to-female ratio was 1.04:1. Peak age at onset was 15-16 years (range 1.1-24 years). T1D incidence <25 years per 100,000 population/year increased from 0.12 in 2007 to 0.74 in 2016 (an 18% annualized increase, p < 0.001). Incidence peaked at 0.80 in 2014, the year after an education campaign was conducted. Incidence <15 years rose from 0.12 to 0.35 per 100,000/year in 2007 and 2016, respectively, (14% annualized increase, p < 0.001). There was a steep, consistent increase in prevalence (per 100,000) from 0.43 in 2007 to 2.90 in 2016 (p < 0.001). Prevalence <15 years was 0.34/100,000 in 2007 and 1.02/100,000 by 2016 (p < 0.001). Overall crude mortality rate was 30.0/1000 patient years, equating to a standardized mortality rate of 9.0, with vital status known for 99.8% of cases.

Conclusion: Known incidence and prevalence of diabetes in Mali increased rapidly from 2007 to 2016, contemporaneous with the introduction and development of the Santé Diabète/Life for a Child program. Improved diagnosis and care resulting in lower mortality are likely contributors. True incidence may still be underestimated, with some cases still dying undiagnosed and full study ascertainment being uncertain.