If you know anything about TB you’ll be well aware that good news in the field of MDR-TB is hard to find. In fact we’d never really heard much at all - but then nor had we heard of Chuuk.
Chuuk is one of several US-affiliated island states among the so-called Federated States of Micronesia in the western Pacific. (It’s also, incidentally, one of the last places on earth where you can find the traditional Pacific master navigators who can make safe landfalls at distant oceanic islands just by using the stars, the clouds, wave patterns and the behaviours of seabirds). The Chuuk archipelago boasts a total population of 53 thousand people (pretty much equivalent to a small town), and, like many others in Micronesia, it has a TB problem.
Then, in 2007, one particular island in the archipelago, Weno, reported an outbreak of MDR-TB. It's a small island with just 15,000 inhabitants – but rather frighteningly it reported not one but two simultaneous outbreaks of different DR strains (one of which was resistant to three TB drugs, and the other to five). Exactly how these outbreaks occurred remains a mystery, but what happened next constitutes a story, not just of extraordinarily good treatment, but also of hope.
Because of Chuuk’s affiliation with the U.S. this double outbreak was fortunate enough to receive the immediate attention of the Center for Disease Control (CDC).
Bearing in mind that with TB things normally happen slowly this tiny outbreak grew fast: four of the first five cases died in the first eight months (including a two year-old child and its mother). Unfortunately because of the bureaucracy involved it almost always takes time to procure the necessary second line drugs to treat MDR-TB. In this instance even with the CDC aboard it still took more than a year during which the infected cases were sent home because of lack of facilities. As a result by July 2010, when things had swung into action properly, they had 25 cases under treatment.
Dr Richard Brostron of the CDC sums the outbreak up very simply:
“What happens when you have two MDR-TB cases and they don’t get treated for a year is that you end up with more – and in the end we had 41 cases of drug-resistant tuberculosis in addition to our contacts.” In the early stages this made for 6 new cases in the first year, and then 22 in the second Put this in epidemiology-speak and it means that the incident rate of MDR-TB (before treatment began to bite into the epidemic) had risen from 13 to 147 per 100,000 population in just two years. Apart from the 1,130% increase in new infections, the rate itself is pretty terrifying for MDR-TB. The increase offers us a clear picture (if one is needed) of how MDR-TB can take off when it finds an isolated environment that’s ideal for it.
The following graphic (which is the CDC’s) gives a complete picture of the waves of the disease – how it first took off (taking nearly all of its victims with it), then stalled once treatment was begun (presumably as community infection was reducing), and then offered up a lesser resurgence before it finally expired altogether.
What this shows beyond doubt is that concerted treatment of MDR-TB works, and (in TB terms) it can even work fast if it’s caught early.
The treatment outcomes recorded in Chuuk (which are shown below) are truly remarkable because, aside from those who died during the initial delay in getting treatment started, an astonishing 97% had successful outcomes. This percentage is almost exactly double the WHO’s globally reported current success rate of 48% (which as you’ll see in the next graphic hasn’t really changed since 2009). What’s more it’s even higher than the global target that’s just been set for much more easily treatable drug-susceptible tuberculosis (which is 90%).
So what went right for a change?
Well first of all a proper treatment programme was rolled out and this was then meticulously supported. Secondly the general approach was fundamentally patient-centred o as to maximise the chance that the patients kept taking their drugs. But probably most importantly of all, every possible contact of each and every infectious case was identified and evaluated (232 of them), then tested for latent infection and if necessary put on a special treatment programme to treat their latent disease. This approach is called ‘active case finding’ – getting out there out to look for potential new cases rather than waiting for them to present themselves after infecting others – and it looks like it’s an essential component of any MDR-TB programme if success is seriously intended. The patients who were enrolled in this secondary precautionary programme were then monitored for a further period of 36 months.
The results from the contact tracing efforts are also both extraordinary and exemplary. An encouraging 89% of those who began treatment for what was suspected latent drug-resistant disease completed it, with not one of them developing active disease. However 14 of those who had been found and tested positive for latent disease refused treatment – and of these two went on to develop MDR-TB. They may well, in fact, even have contributed to the secondary surge in the graphic above.
An obvious question arises: if an epidemic of such a challenging lethal disease was essentially wiped out in an out of the way place like Chuuk, why can’t it be done elsewhere?
(To put this in perspective, it was reckoned in the WHO’s most recent estimate of MDR-TB that there were 480,000 new cases of MDR-TB in 2013, but there were probably almost as many deaths. Globally it's as good as certain that the vast majority of MDR-TB cases are currently being lost to the disease.)
The answer to why this disease isn't yet under control is right here in the story of Chuuk. It's because appropriate help isn't yet being given where it's needed. In this instance it took the help of a global health superpower – America and its CDC - which threw a diminutive part of its resource at an otherwise insuperable problem on a tiny island – which then got sorted out in six years. But this particular response didn’t just treat the disease properly, it also went looking for every possible future case it could find and then treated each one it could to stop further disease breaking out. In other words, the health workers in Chuuk were helped to get ahead of the disease rather than the other way around.
So if those entrusted with protecting the health of mankind are really serious about responding to MDR-TB they now need to weigh up the world’s health resources and plan cording. The countries with the strongest health services are going to have to help those with the weakest – or the whole world will end up paying a lot more in the end and millions are going to have died along the way.
We've recently offered our opinions on this issue in a little more detail to the Stop TB Partnership in Geneva. We know that they’ve taken note of what we’ve offered but we’re hoping for further response in the coming months. Chuuk may be no more than a tiny dot in an immense ocean, but its story gives cause for hope - but only if world leaders and global agencies care to recognise it.