This year’s Global Report on TB was published last week by the WHO. It’s become a custom for us to comment on it on each occasion.
First of all, we immediately recognise that in the 26 years since TB was first declared a Global Emergency (and indeed in each of the years since when we have been commenting on them) these reports have improved immeasurably. Now, for instance, they appear replete with data with which they were appallingly deficient in their earlier editions. But just like with the TB emergency itself, there’s been an awful lot of catching up to do, and it’s self-evident that much more is still needed in these reports - not least to enable accountability.
This report is the first to be published since last year’s High Level Meeting (HLM) on TB at the UN. Because it was such a milestone this report emerges as one of special interest, not least because of a bunch of targets which were unanimously committed to by all member states in the HLM's political declaration. These target...
“Extrapulmonary TB represented 14% of the 6.4 million incident cases that were notiﬁed in 2017, ranging from 8% in the WHO Western Paciﬁc Region to 24% in the WHO Eastern Mediterranean Region.”[i]
This is a direct quote from the last WHO Global TB Report (and another one is due very soon). They published a helpful map to illustrate this identifying where the highest proportions of extrapulmonary TB (EPTB) are known to exist.
It’s a revealing one. You’ll see immediately that, apart from Mongolia and a couple of smaller countries in Central Asia, no higher burden TB countries appear to have found much extrapulmonary TB (EPTB) at all. In fact most have reported 0-19% (and of course we already know from the sentence at the top that the global average of notified cases is 14%).
This is curious – in fact we think that it may be more evidence of an underestimation of disease (and therefore ongoing neglect). We’ll try to explain why.
Firstly, we think it’s curious that there was no estimate anywhe...
It’s about 500 miles from Pyongyang in North Korea to Beijing in China - at least it is if you fly as the crow does. North Korea’s Koryo airline, however, takes an altogether more circuitous route, avoiding the sea and tracking a course over the land some way inside the curve of the coastline – first north-west up towards Manchuria, then west and finally southwest and south down towards the Chinese capital. So instead of taking not much more than an hour, this longer route therefore takes over two.
Why they take this longer route is their own business. But because of it, if you look out of a porthole on the right just as the noise of the engines change and the plane starts to dip down towards Beijing you’ll see an unlikely thin grey line tracking rather crazily across the ridges of the jagged mountains below.
This is the eastern end of China’s Great Wall, meandering off westwards along the mountainous crests. Seen from this aerial perspective you can get a real idea of just what an extra...
Let’s set the scene by starting with some much-needed good news.
Protection from further infection afforded by a TB infection
In the process of writing these blogs we’ve come to a new appreciation of how the risk of a re-activated infection following an initial latent infection falls so ‘precipitously’ after the first twelve months after infection[i]. Put in the simplest of terms, this means that if you’re unlucky enough to have spent some limited time in the presence of an infectious TB patient and a year later you haven’t developed any signs or symptoms of disease, then your chance of developing TB is generally pretty slim.
What this further suggests is that, after a certain delay, the host immune response to TB may well manage to literally sterilise the infection, and could even do so in the vast majority of cases – so (in the simplest of terms), while all of those current 1.7 billion latent infections worldwide might still test positively for latent disease, only those most recently e...
So far we’ve looked at some of the complexities and uncertainties relating to these so-called ‘latent’ aspects of a pandemic plague of sub-clinical infection. We’ve wondered how the outflow from this immense 1.8 billion-strong ocean of potential infection into the active sea of re-activated infectious TB might be stifled with effective targeted treatment. Doing so could help starve the disease of what it essentially needs - but yet we seem to be as far away from this goal as ever, particularly in respect of the proportion of latency which is drug-resistant.
Ultimately this is a numbers game – and we can say two sure things about them. Firstly, we can say that all the numbers are very uncertain; but secondly that the odds within the numbers still appear to be leaning in TB’s favour, not just because it’s impossible to tell if a case is drug-resistant when it’s latent, but because there now appears to be a disquieting amount of drug-resistance (either mono-drug resistance or multi-drug re...
In Part 1 we discussed the nature of latent TB (LTBI), and some of the current (and recurrent) deficiencies in treating it.
In this part, we discuss specifically how LTBI is treated and, in relation to this, how much of the immense pool of latent infection might already be drug-resistant because this is a critical issue.
So how is LTBI treated?
The most recent WHO guidelines include four options for treatment of LTBI, including three new shorter drug regimens
A daily dose of isoniazid for at least 6 months (this often is extended to 9 months).
A weekly dose of rifapentine and isoniazid for 3 months.
A daily dose of rifampicin plus isoniazid daily for 3 months.
A daily dose of 3–4 months of rifampicin.
It’s reckoned that a 60-90% risk reduction of developing active TB is achievable using these treatments. It should be further added that (for reasons that will become obvious below) further regimens are being tested including using second line drugs like levoflaxicin an...
In the last month two studies have been published which have focused our attentions on latent TB - not least because their contents have highlighted the potential importance of some of our latest findings.
What follows is an extended discussion on the complexities of latent tuberculosis. It consists of four parts:
Part 1: discusses latent TB, the primary invisible plague, and the current efforts to address it.
Part 2: discusses the secondary doubly invisible plague of latent TB that is drug resistant.
Part 3: discusses the recent data released to us by the North Korean Ministry of Public Health relating to the potential use of moxa as an adjunctive tool for treating latent TB including latent MDR-TB.
Part 4: discusses some further incoherencies which emerge from these new studies and some additional complexities.
So what is ‘latent’ TB?
A latent TB infection (LTBI) is defined by the WHO as being “a state of persistent immune response to M. tuberculosis without any clinical clinically manifest...
We came across this headline last week in the UK national newspaper the Daily Mirror.[i] Naturally it drew our attention, and (along with raising our eyebrows...) it’s raised such important issues for us that we feel we must discuss the scale of iniquity that this report inadvertently highlights.
The story reveals how 64-year old Margaret Pegler, long-time resident of Welsh village Llwynhendy in south-west Wales, died of TB last autumn at the age of 64. Her family are angry (which was the reason the story was published) because they reckon that she died because the signs of her illness were missed until it was too late.
They may be right – but the truth is that TB in Wales is so well managed and now so unusual that doctors really aren’t that alert to it.
Sixty years ago which may well be when Margaret Pegler was originally infected with the disease (with it remaining in sub-clinical latency for the last six decades before breaking out in the last years of her life) this certainly wouldn’t...
Yesterday was International Women’s Day (and what’s more, World TB Day is now less than a fortnight away).
Given the significance of yesterday, we feel it important to recognise that we have some extraordinary women in our little team not just here in Europe but also providing vital support in Japan as well. Thank you!
What’s more, over the past decade we’ve had the rare privilege of meeting and working with some truly extraordinary women in Uganda and South Africa – women who we recognise to be on the front line of the battle against this disease making sure that TB patients take their drugs. What's more are they live at maximum risk of infection themselves and get little in the way of pay or recognition for this (even too often being given little or nothing in the way of protection). Reflecting on the importance of yesterday,it makes us realise the importance of reminding the wider world of this fact.
In the next fortnight we expect to meet a new group of these women in Angola where we...