DARTZ: Diabetes and Risk of Tuberculosis in Zambia

The Diabetes and Risk of Tuberculosis in Zambia (DARTZ) studies have been investigating how diabetes, commonly known as sugar or sugar disease, affects tuberculosis (TB) control in Zambia.
In Zambia and other countries in sub-Saharan Africa, there is a high prevalence of HIV, much higher than many other places in the world. A lot is already known about how HIV affects TB and its control, but little is known about how HIV and diabetes together affect TB. One DARTZ study therefore focuses on this so that we can understand it better.
There is a high prevalence of poorly controlled (severe) diabetes among those who have diabetes in Zambia and surrounding countries compared to the rest of the world. The actual prevalence of diabetes in many parts of Africa is still unknown, but those who do get diagnosed with diabetes may not often get diagnosed until they have had the disorder for a long time. They may not be able to access adequate treatment, meaning that they remain having poorly controlled diabetes.
The prevalence of diabetes is likely to rise over the next few decades because of changing lifestyles and diets. Another DARTZ study is investigating whether the level of sugar in a person’s blood affects the outcome of TB treatment, for example, whether or not those with very high levels of blood sugar are more likely to have a worse TB treatment outcome than those with slightly high or normal blood sugar levels.
The final DARTZ study is exploring how diabetes can be diagnosed among patients with TB. There are a number of different tests that diagnose diabetes, but it is not yet clear which one is best for this particular group of people. This is because aside from diabetes, a high blood sugar level can be caused by a severe infection such as tuberculosis. This latter cause is often called stress-induced hyperglycaemia. It is important to know whether the high blood sugar level is caused by diabetes or by stress-induced hyperglycaemia, so that the most appropriate action can be taken for the treatment of individuals and for any necessary prevention in the population. The final study aims to distinguish between these two causes of high sugar and investigate which measure of blood sugar best identifies those who have diabetes rather than stress-induced hyperglycaemia among adults with newly-diagnosed TB.
Collectively, these studies will increase our understanding of how high blood sugar affects TB and its control in Zambia and other countries in Africa. This will allow for better preparedness for the predicted rising prevalence of diabetes in this sub-region.
The DARTZ studies are funded by the Welcome Trust and are expected to complete data collection in June 2015.
The HEAL Project
Whilst based in Lusaka to run the DARTZ studies, Dr Sarah-Lou Bailey lives with a group called the HEAL (HIV Empowered and Living) Project, in their Transit Home.
About the HEAL Project
The HEAL Project is run by a group of people living with HIV/AIDS who work together to help themselves and others in their community to a better life, free from sickness and vulnerability.
The group supports income generating schemes and runs a community school for children whose parents have been made vulnerable because of HIV, TB or other related illnesses. In this situation, the parents are often no longer able to provide for the family, and so without the HEAL Project school the children would be forced to stop going to school.
The group also recognises a need to support children including adolescents who have been orphaned by TB-HIV/AIDS and are currently looking after 30 children who have no one to care for them. Once with the HEAL Project in their Transit Home the children have access to healthcare and can attend school.