South African researchers have found that in areas where tuberculosis is endemic, nearly one in three children and adolescents with type 1 diabetes tests positive when given a skin test for the disease. Although the positive test results do not mean that these young people will inevitably develop active TB, they do run a very high risk of doing so.
Researchers from the Desmond Tutu Tuberculosis Center in Cape Town, South Africa, studied the prevalence of TB among 258 patients who were under 21 years of age, had type 1 diabetes, and lived in areas where TB is common. They found that 29.8 percent of the patients were infected with TB-almost one in three-with 3.48 percent suffering from active TB. Sixteen of the youths studied, 6.2 percent, had previously been treated for the disease.
The research team concluded that the prevalence of TB among young people with type 1 diabetes was more than 6.8 times greater than its prevalence in the general population. The team also said that poor control of diabetes produced a 1.39 times greater risk of acquiring TB, while contact with a source of TB created a 2.78 times greater risk.
In studying the relationship between diabetes and TB, the scientists are caught in a kind of chicken-and-egg quandary: Does poor blood sugar control predispose type 1s to developing TB after they are infected with the disease, or is poor blood sugar control a consequence of it?
In any case, given the higher risk for TB experienced by young people with type 1 diabetes, the team recommended that authorities and healthcare workers routinely test them for the disease.
Tuberculosis is a highly contagious airborne bacterial disease, spread by coughing, sneezing, spitting, and even the simple act of talking. Current estimates indicate that almost one billion people worldwide either have or will develop latent TB, a dormant infection in which they don’t feel sick, don’t show any symptoms, and are not contagious. About 10 percent of them will later develop active TB, which is infectious.