New research has bad news for millions of South Africans with high blood sugar: they are three times more likely to develop active tuberculosis.
Diabetes is “quietly fuelling the spread of tuberculosis” and this “looming co-epidemic” threatens to undo the gains made in controlling TB over the past decade, warns the World Diabetes Foundation and the International Union Against Tuberculosis and Lung Disease.
The new report was released at the 45th Union World Conference on Lung Health in the Spanish city of Barcelona on Wednesday.
The immune system is weakened by diabetes, a chronic noncommunicable disease, making it less able to fight off TB germs: a person with diabetes is three times more likely to develop a TB infection, the report notes.
“Diabetes affected 382?million in 2013 and will increase to a predicted 592?million by 2035. As diabetes spreads, it will cause more and more people to develop TB.”
The International Diabetes Foundation estimates that about two million South Africans have the condition. But the true number is likely to be higher because in most developing countries “less than half of people with diabetes are diagnosed”.
Awakening dormant TB
TB remains the second biggest infectious killer globally – behind HIV. In 2013 1.5?million people died from this generally curable disease, according to the World Health Organisation.
One in three people worldwide are infected with TB but only 10% of these will develop an active infection – in the rest the TB will remain dormant for their lifetime, the authors note.
But developing diabetes can increase the chances of a dormant TB infection becoming active.
The report also points out that people with both conditions are more infectious and are more likely to transmit their TB germs to others.
The rate of increase of diabetes in sub-Saharan Africa is the highest in the world, according to Jeffery Wing, an authority on diabetes from Charlotte Maxeke Academic Hospital in Johannesburg. He says it is the “fastest growing epidemic in the region”.
“Already about 15% of people over the age of 50 in South Africa have diabetes.”
Wing says that more people are developing noncommunicable diseases – in particular diabetes – which usually appear later in life, because antiretrovirals allow HIV-positive people to live longer.
South Africa is already experiencing the dual epidemic of TB and HIV, with 70% of people with TB also living with HIV, according to the South African National Aids Council.
The report’s authors criticise the global response to the TB-HIV epidemic as being too slow.
They urge public health authorities and policy makers to “urgently address” the co-epidemic of TB and diabetes through prevention, screening and treatment and not “let history repeat itself”.
Amy Green attended the 45th Union World Conference on Lung Health as part of a National Press Foundation funded fellowship