Keeping watch on the TB time bomb
The TB Time Bombs, makes for alarming reading. When it comes to patients with extensively drug-resistant tuberculosis (XDR-TB), hard-pressed health services in South Africa have run out of treatment options. They are sending them back into their communities.
With nothing more than a flimsy surgical facemask between them and the people they mingle with, the alarm bells are ringing. “Its a public health emergency,” declares Keertan Dheda, a TB specialist at the University of Cape Town. And a growing one. Doctors now see upwards of 8,000 new cases of XDR-TB in South Africa every year. At best only 20% of them will be cured.
But this is just the tip of the iceberg. South Africa is the wealthiest place on the continent with some of the best medical facilities. If they are struggling to cope, imagine the crisis amongst their poorer neighbours – Swaziland, for example, with its deadly double: the world’s highest incidence of TB and high levels of HIV co-infection. According to the World Health Organization (WHO), 47% of people with active TB there remain undiagnosed, blithely continuing to spread the disease.
The problem extends well beyond Africa with the incidence of XDR-TB or multidrug-resistant TB (MDR-TB) rising globally. India, with its crowded slums and pitiful health services, is probably the biggest concern.
But the rich West does not duck this bullet. Travellers are catching the disease and bringing it home in increasing numbers. And when drugs don’t work, it makes little difference whether you are in Mumbai or Melbourne.
Stemming the tide is no simple matter. As one TB expert told COSMOS: “What response do you think you will get if you tell a health minister in a developing country he must spend half of his scant budget on treating TB?” In reality the equation is pay half the budget now, or twice as much when the problem spirals out of control.
Stopping the spread of XDR strains will take a new generation of drugs. But who knows how long that will take? Bedaquiline, the first new drug in 40 years, was approved last year but to safeguard its efficacy, its use is restricted to treatment “virgins”. Meanwhile, with XDR patients at large in their communities, the WHO is pursuing other strategies. One is simply to gain knowledge: there is little data on how XDR is spread. And so the initiative of the team of researchers at South Africa’s Cape Town University is to be applauded.
On one hand they are developing a test for “super-spreaders” – patients who for unknown reasons carry orders of magnitude more virus particles in their coughs than most.
These would be the ones to monitor closely. And the researchers are developing the high-tech system to do so. Their patients may be wearing flimsy facemasks but they are fitted with GPS transmitters to track their movements and heat sensors to check whether the masks stay on.