Miriam Mannak
CAPE TOWN, Nov 8 2007 (IPS) – What is known so far about the scope and prevalence of extensive drug-resistant tuberculosis (XDR-TB) in sub-Saharan Africa may only be the tip of the iceberg, said TB experts Thursday during the 38th Union World Conference on Lung Health, in the South African coastal city of Cape Town.
The Nov. 8-12 meeting, being held under the theme Confronting the challenges of HIV and MDR in TB control and care , is organised annually by the Union Against Tuberculosis and Lung Disease an international coalition.
According to the World Health Organisation (WHO), 41 countries worldwide have reported cases of XDR-TB to date. Two are situated in Africa, Mozambique and South Africa, with the latter worst affected. In 2006, the South African Department of Health registered 419 cases of XDR-TB. This figure is on the rise: in the first quarter of 2007 year, 391 cases were reported.
But, just because only two African countries have reported XDR-TB cases, it cannot be assumed that the disease does not affect the rest of the continent, said Mario Raviglione, the director of the WHO s Stop TB Department.
We do not know about the situation in most African countries because there are simply no laboratories that are able to test for and detect XDR-TB, he explained at a press conference. Unfortunately, if no cases are reported it is impossible to determine what the extent of the XDR-TB problem is in these countries.
TB is an airborne disease that mostly affects the lungs and is transmitted through coughing, sneezing, spitting or speaking. Tuberculosis bacteria can remain dormant in a patient, but become activated if a person s immune system is compromised.
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XDR-TB is a more serious form of Multidrug Resistant TB, which is impervious to at least two of the principal drugs normally used to treat TB (referred to as first-line drugs ). XDR-TB is resistant to various second-line drugs as well.
Several factors can cause TB bacteria to develop resistance to drugs, including failure by patients to complete treatment a six-month course of antibiotics.
Raviglione told IPS that there is an urgent need for better laboratory infrastructure in poor countries, especially those with a high prevalence of TB: It is crucial to develop more efficient and reliable ways to test people so they can be treated (in) timely (fashion), so that they can t spread the disease further.
One of the methods of testing for TB involves injecting an extract of dead tuberculosis bacteria into the skin. If this causes swelling, the person concerned may be infected.
However, TB tests are not completely reliable. In the case of people living with HIV/AIDS, for instance, swelling may not occur, as their immune systems have been undermined and are unable to react to the injected bacteria.
I underwent four tests, including a skin test, and they were all negative, said Ezio Santos Filho, an internationally known AIDS and TB activist from Brazil who has lived with HIV for 20 years. He contracted TB twice: It was only after a chest X-ray that TB was confirmed.
Education and awareness play a vital role in curtailing the spread of XDR-TB. TB patients need to know about the dangers of mismanaging their treatment, Thami Mseleku, director general of the South African Department of Health, told IPS. They also need to know what to do if they are infected with XDR-TB.
Addressing the stigma around HIV/AIDS should be part of making people aware, he added. We discovered that people are reluctant to get tested for TB because they do not want to be associated with HIV/AIDS.
TB is very common among people living with HIV, as their compromised immune systems are not able to fight the disease. In sub-Saharan Africa more than 60 percent of HIV positive people suffer from TB.
But, Mseleku warned that it is not necessarily a good thing to treat HIV and TB as a single epidemic. It could be interpreted as if HIV and TB were inseparable, that if you have TB you also have HIV. We think this could discourage people from getting tested for TB.
Better laboratories and education are not all that s required in the fight against XDR-TB. There also need to be improvements with medication, said Giorgio Roscigno of the Foundation for Innovative Diagnostics (FIND).
FIND is a Geneva-based organisation that aims to develop rapid, accurate and affordable TB tests with assistance from the public and private sectors.
Drugs that are used to treat TB have not been subjected to improvement for 40 years, Roscigno said. The TB vaccine is 80 years old. We cannot overcome the problem without better treatment.
Fortunately, there is positive news on the horizon: At the moment, seven candidate TB drugs are entering the first stage of clinical trials. Two of them could be suitable to treat drug-resistant TB strains, Roscigno added.
We need to avoid at all cost that resistant strains replace treatable forms of TB. The worst case scenario is that resistant strains take over, become the norm and become even more drug-resistant. We need to turn off the tap and avert a total disaster.
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