Thursday, 27 March 2014

Why Africa's drug-resistant tuberculosis is proving so hard to fight


A medical worker is pictured at a mobile testing facilities for Tuberculosis in South Africa.
JOHANNESBURG, South Africa — Humanity thought it had tuberculosis beat.
The dreaded “consumption,” one of the world's oldest diseases, had plagued the ancient Egyptians and ravaged 19th-century Europe and North America. New drugs in the 1940s made it possible to beat TB at last, and the number of cases plummeted.
Fast-forward a few decades. Virulently drug-resistant strains of TB have emerged, treatment has not kept pace, and the disease is again on the rise, infecting more than 8 million people a year.
In South Africa, one of the hardest-hit countries, tuberculosis is the leading cause of death, responsible for 1 in 10 deaths in 2011 and killing an astonishing 54,112 people country-wide, the country's statistics bureau said last week. The second leading killer that year was influenza and pneumonia, with some 20,000 fewer deaths.

Not only is there multi-drug resistant TB, but there is also something called extensively drug-resistant TB (abbreviated as XDR-TB), which is almost incurable. But despite these dangerous new strains, treatments are largely unchanged. US regulators have approved only one new drug in the past 50 years.
A new documentary film, “TB Silent Killer,” captures the horrors of the old-fashioned, increasingly ineffective treatment process for patients with drug-resistant TB: months of painful injections and handfuls of expensive pills that must be taken daily for about two years, despite severe side effects including deafness.
Even then, there is no guarantee the treatment will work. More than half of these multidrug-resistant TB patients will likely die. In South Africa, only 13 percent of XDR-TB patients are cured.
The documentary takes place in Swaziland, a small, mountainous country bordering South Africa that has the highest incidence rate of TB in the world.
One young woman named Gcnenikele, who has been diagnosed with XDR-TB and lost her parents and sister to the disease, decides to give up treatment and spend her last few weeks at home, in isolation.
She had to drop out of university because of the disease, and has gone deaf from the drugs, which aren't working.
“My mind is so suicidal," Gcnenikele says. “When I look at a rooftop, I think to myself, I wish I knew how to tie that knot.”
“I'm not going to win this battle. I'm not going to win it.”
While TB occurs all over the world, Asia and Africa have been particularly affected. Sub-Saharan Africa, where TB has been closely linked with the HIV epidemic due to HIV’s weakening effect on the immune system, carries the greatest proportion of new cases per population, according to the World Health Organization.
British filmmaker Jezza Neumann said that multi-drug resistant TB is “considered a disease of the poor,” and has been largely ignored by Western countries.
“Until recently the perception is that its been eradicated from Western civilization,” he said. “If you look at the history of HIV, it only became something considered a serious thing to deal with by the West when it started affecting the West.”
Neumann describes TB as a “social disease” that thrives in areas of deprivation, preying in particular on people with weakened immune systems. But, he adds, as Western countries become less equal and more economically vulnerable, TB could become a bigger problem in the future.
Drug-resistant TB has already spread around the world — as of late 2013, XDR-TB cases had been reported in 92 countries.
In South Africa, doctors are desperate to have proper medicine to treat their patients, but efforts by groups such as Doctors Without Borders (MSF) are stymied by drug patents and lengthy approval processes.
Two new drugs that have shown promise in treating drug-resistant TB aren't yet widely available in South Africa.
One of them is a super-strong antibiotic called linezolid — for which drug firm Pzifer holds the patent, meaning that MSF must pay R700 (about $65) per tablet per day. It costs about R123,000 ($11,300) per patient for 6 months of necessary treatment, though some patients must take linezolid for 18 months.
South Africa's drug control agency is fast-tracking approval of a generic version, but the process could still take 18 months.
The other new drug, bedaquiline, has been granted accelerated approval in the US by the Food and Drug Administration but is still undergoing clinical trials in South Africa and has not yet been registered for use in the country.
Jennifer Hughes, an MSF doctor who works with TB patients in the sprawling Khayelitsha township near Cape Town, watches her patients struggle with “really horrendous side effects” from the older drugs they must take. These include hearing loss, psychosis and severe nausea.
Side effects from newer linezolid and bedaquiline are believed to be less severe, but the drugs must be taken as part of a cocktail to combat the most drug-resistant forms of TB.
Hughes notes that in South Africa, the general trend is that new TB cases are declining — but the number of multi-drug resistant cases is going up every year.
Drug-resistant varieties of TB first emerged as a result of TB patients defaulting on their medications. Now, these strains are being passed through the air from person to person. More than 80 percent of cases of MDR-TB are transmitted in this way — simply by breathing it in, Hughes said.
“It's the transmission that's the worrying thing,” she said. “With global travel, you just don't know if somebody coughing on the airplane has TB.”
Poor diagnosis of multi drug-resistant TB is another problem. WHO last week called for earlier and faster diagnosis of the various forms of TB, to save lives and help stop the spread of drug-resistant strains.
Fewer than one in four cases of multi-drug resistant TB are properly diagnosed, meaning that many people are at risk of dying due to the wrong treatment, WHO director general Margaret Chan said Thursday ahead of World TB Day, held annually March 24.

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