Diseases and Disorders HIV and AIDS HIV Treatment Public Health & Health Systems Science, Research & Innovations Tuberculosis (TB)

Impact of XDR-TB on HIV
Living with AIDS # 276

The deadly strain of extremely drug resistant TB has reared its head in Gauteng. Experts fear that the outbreak ‘€“ first detected in KwaZulu-Natal – is a potential killer, particularly for people living with AIDS. There are concerns that it also places South Africa’€™s AIDS treatment programme at enormous risk.

KHOPOTSO: Only one of the 53 people who were diagnosed with the highly infectious  strain of Extremely Drug Resistant Tuberculois (XDR-TB) at the Church of Scotland Hospital, in Tugela Ferry, KwaZulu-Natal, is still alive. They were participants in a research project looking at how best to combine antiretroviral treatment with TB treatment. 44 of the 53 participants had been tested for HIV and were confirmed positive. All but one of the 53 people died within three weeks of being diagnosed with XDR-TB. Professor Willem Sturm, who works with the University of KwaZulu-Natal Medical School, explains further.

 

Prof. WILLEM STURM: While the patients were responding to antiretrovirals, their CD-4 counts started rising, they died from tuberculosis while they were on TB treatment’€¦ The antiretrovirals did work, but the anti-TB medication did not work. So, when we then started looking at what was the cause of that, we found that they were infected with this extreme(ly) drug resistant strain of TB.            

 

KHOPOTSO: With no appropriate treatment for this form of TB, the only survivor is still holding on tightly to his life under medical supervision at the Church of Scotland Hospital.

 

Prof. WILLEM STURM: Not on TB medication because there is no suitable medication at the moment for those patients. He’€™s on antiretrovirals. If his immunity comes up’€¦ then this patient might survive by just conquering the TB himself.

 

KHOPOTSO: Sturm says this condition thrusts us back to the period when there were no drugs available to treat TB. In 40 years, no new drugs have been developed for tuberculosis. Dr Kenneth Castro is the Director of the United States’€™ Centres for Disease Control and Prevention’€™s Division of TB Elimination.

 

Dr KENNETH CASTRO: It’€™s going to be imperative to develop new treatment regimens to overcome this ‘€“ not unlike what we’€™ve seen very successfully done for HIV. The number of antiretroviral agents that exist nowadays are difficult to keep up with.

 

KHOPOTSO: Some doctors say that the patients in Tugela Ferry were diagnosed late during infection and nothing could be done for them when the disease was already raging. This means that more specific and even quicker means of diagnosing XDR-TB are needed. Dr Matteo Zignol is a medical officer who works with the World Health Organisation’€™s TB Strategy and Operations Unit ‘€“ Stop TB.

   

Dr MATTEO ZIGNOL: To diagnose XDR-TB you require more sophisticated methods compared to the diagnosis of sensible TB; and you require much more time. This is a great challenge for patients that are affected with this form of tuberculosis.

 

KHOPOTSO: But, added Zignol, even if that can be done, successfully managing people co-infected with HIV and TB will always remain a medical challenge.

 

Dr MATTEO ZIGNOL: And the second challenge that will emerge is probably the interaction between the use of second-line drugs to treat TB and the use of antiretroviral drugs for HIV, particularly in a country like South Africa, where a large proportion of the population with TB is also infected with HIV. We need to work more to understand better the interactions between drugs to treat these two diseases.                      

 

KHOPOTSO: That is important in the light of the fact that medical professionals have found that Rifampin, one of two drugs used in the treatment of normal TB interacts negatively with a group of antiretrovirals in a class known as protease-inhibitors. Dr Castro of the United States’€™ Centres for Disease Control and Prevention.

 

Dr KENNETH CASTRO: Rifampin when taken alongside some drugs or the antiretrovirals could result in interactions that lead to toxicity and side-effects… Basically, what happens is (that) Rifampin induces the body to metabolise or get rid of some of these other drugs, so the other drugs are rendered ineffective. Conversely, some of these other drugs will almost paralyse the metabolism of Rifampin, in turn leading to toxic levels of Rifampin. But that can be very easily overcome by using antiretroviral regimens that don’€™t have drug-drug interactions with Rifampin.

 

KHOPOTSO: Anyone can get XDR-TB, but those whose immune system is weakened, such as in the case of people living with HIV, are at greater risk of infection. Better diagnostic measures and surveillance systems are very important to keep track of how the strain is spreading. But of immediate importance, TB experts agree, is the procurement of drugs needed to treat the disease. The Department of Health this week announced in a statement that it’€™s in the process of securing the medication. Dr Castro again.

 

Dr KENNETH CASTRO: Registration of these drugs needs to be applauded because, very often, that’€™s not done and that’€™s an immediate need that will be fulfilled’€¦ so that we don’€™t have the unnecessary deaths that are now occurring. And in a setting where you are threatening incipient antiretroviral programmes we can’€™t afford to have people coming to get their antiretrovirals only to get an incurable version of TB. This we must avoid.

About the author

Khopotso Bodibe