SA’s TB cure rate still poor
Little more than half of all tuberculosis patients are cured in South Africa, multi-drug resistant TB is on the rise and government seems unable to address the disease.
Yet there is some hope in the field of drug development, with renewed attention being paid to developing better medicines.
In 2003, around 185 000 new TB cases were diagnosed in South Africa. This figure rose by a massive 94 000 cases in a single year, with 279 000 being recorded in 2004.
South Africa’s cure rate of 54 percent falls pitifully short of the World Health Organisation’s goal of 85 percent..
‘When you consider that South Africa is the richest country in Africa, we are really not managing this problem as well as we should. And, although we talk about prioritizing it and saying ‘yes, yes, it’s important’, I’m not sure that we really do manage it as a priority at every level,’ says Professor Mary Edginton of the Witwatersrand University’s School of Public Health.
‘TB is killing people daily. People don’t always understand that it can be treated and cured. It creates a stigma because it is associated with HIV,’ adds Edginton, who is also the manager of Chris Hani Baragwanath Hospital’s TB Care Centre.
She points out that South Africa has the eighth highest TB burden in the world and deaths from untreated TB are high.
Edginton believes that if South Africa is going to manage the problem, it needs to start with a patient-centred approach ‘ establishing ‘what do they need, what do they want and how to get the information across to them.’
Dr Lindiwe Mvusi, National TB Manager in the health department, acknowledges that there are many problems but says that ‘the situation has improved slightly because of awareness with people coming in earlier (to be tested). Our problem with the adherence to treatment is still there.’
Mvusi believes that the increase in cases shows that people are reporting to clinics at an earlier stage of their TB infection.
Edginton says that there needs to be honesty around the complexities of testing for TB. ‘It’s not a simple blood test or a simple finger prick or swab in the mouth in order to subject a specimen to a test where you get an immediate result,’ she says.
At the moment, patients who have lung TB have to cough sputum (mucus) from their lungs into a bottle. This is sent to a laboratory where it is processed and examined under a microscope by a skilled technician who them produces a result.
‘At best, very best, this takes 24 hours. The goal in the country is for it not to take more than 48 hours. We still have many clinics and even hospitals in our country where it takes up to a week,’ says Edginton.
‘So, the patient is left wondering what’s happening,’ adds Edginton.
She believes that multi-drug resistant (MDR) TB is a huge, incredibly dangerous and horrible problem. MDR TB is TB that does not respond to the usual six-month course of ordinary TB drugs and needs more expensive drugs that are taken for about 18 months. Usually only half of MDR TB patients are cured.
‘Why is MDR TB developing? It’s because the programme is not working as well as it should. It’s as simple as that. It’s a health service management problem,’ says Edginton.
Mvusi reveals that about 1,6 percent of new TB cases are MDR TB while 6,7 percent of patients who are being retreated for TB are diagnosed as having MDR-TB.
HIV is also adding to the TB burden, with a high proportion of people with TB also being co-infected with HIV.
‘TB is missed or diagnosed late in people who are HIV positive, mainly because of the depressed immune system. They do not respond as you would expect in a person who has a strong immune system to respond to the infection,’ says Mvusi,
Then there is the question of giving a person both TB medicine and antiretroviral drugs at the same time.
‘Where patients have a CD 4 count of less than 50, you need to be careful if you introduce both at the same time,’ says Mvusi. ‘If they are not already on ARVs at the time when you diagnose TB, then you start with the TB treatment. As soon as they have settled on that, you introduce antiretrovirals. You need to be careful because, once they develop side-effects, you wouldn’t know what drug is causing what.’
Mvusi believes that the key to success is to ensure that TB cases are detected early and patients complete their treatment.
Meanwhile, Edginton urges that South Africa needs to rise to the challenge a bit faster with more people and more commitment.
‘It probably means more money, but that’s okay because I think we’re rich and could divert more money. I think community education and advocacy is critical. I think we’ve got to get the right message to as many people as we possibly can because too many people present with signs and symptoms of TB too late to have prevented the spread of TB in the community,’ says Edginton.
But amidst the bad news is some good, according to Professor Valerie Mizrahi, co-director of the Centre for Excellence for Bio-medical TB research at the National Health Laboratory Service.
‘The field of TB drug discovery and development is probably at the most exciting junction that it’s been in more than 40 years,’ says Mizrahi.
‘There have basically been no new TB drugs for 40 years and suddenly, over the last five to 10 years, as a result of a number of developments the most important of which is major advances in the science underlying TB disease and the bacteria that causes TB, there’s been an explosion of interest in the field.’
However, she cautions that new TB cures are not around the corner.
‘A tremendous amount of biological uncertainty that still exists. But there’s been enough of a push from the basic sciences to open up areas where the risks for drug development are lower than they’ve been for a long, long time.
‘As a result of this, we’re in a very privileged position of having several new drugs and new drug combinations being tested in Phase 2 trials around the world. South Africa is a premier destination for Phase 2 trial testing. There are some very major studies going on in the Cape Town and Durban areas in this respect.’
The Global Alliance for TB Drug Development has set 2010 as its first target for a new drug to be available, and Mizrahi believes this is ‘a realistic horizon’.
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