UCT study highlights TB danger

Injectable contraceptive – Depo Provera – increases women’s risk of getting the disease

A COMMON injectable contraceptive has now been found to increase women’s chances of contracting Tuberculosis (TB).

This is according to a study conducted by Professor Keertan Dheda and Dr Michele Tomasicchio, at UCT’s Centre for Lung Infection and Immunity.

Injectable contraceptives are widely used across sub-Saharan Africa, being the birth control of choice for about 16.5 million women in the region.

The World Health Organisation cites “their effectiveness, their simple re-injection schedule every two or three months, depending on the brand and their suitability for discreet use” as some of the main reasons for their popularity.

A recent meta-analysis of clinical observational data suggested that Depo-Provera may increase women’s chances of contracting HIV by up to 40%.

This is because the injection contains the synthetic hormone medroxyprogesterone acetate (MPA), which acts as an immunosuppressant.

Considering the prevalence of TB in sub-Saharan Africa, and the fact that it remains the top infectious disease killer globally, Tomasicchio said he realised the necessity of investigating whether the use of Depo-Provera could increase the risk of TB infection.

“We looked at two different injectable contraceptives that are commonly used in South Africa – Depo-Provera and norethisterone enanthate (NET-EN). Our data showed that Depo-Provera increases TB pathogenesis, while NET does not.

“We found that Depo-Provera actually down-regulates immune function genes that are associated with protection against TB, and also up-regulates certain cell types that suppress your immune system,” he said.

Tomasicchio would like to see the study results, along with those of future studies, drive a change in policy surrounding Depo-Provera usage in South Africa.

“My ultimate aim is to make sure that women are aware of the dangers of using (Depo-Provera), particularly in the context of sub-Saharan Africa,” he said.

“What should happen is government clinics in South Africa – and elsewhere – should move over to NET, because it simply is the safer choice.”

Tomasicchio said he planned pursuing this study further, to gain a better understanding of why and how MPA actually drives TB pathogenesis.

Ultimately, he hopes that the mounting evidence showing that Depo-Provera is not the safest choice will be taken to heart by the South African government and that policy changes will be made sooner rather than later.