We are in the midst of a global pandemic.
No, not that one.
Caused by the bacillus myobacterium tuberculosis, tuberculosis (TB) reported 10 million new infections and 1.5 million deaths in 2018. Currently, it is the leading cause of death from a single infectious agent, ranking above HIV/AIDS. The current crisis prompted a new initiative in 2014 from the World Health Organisation (WHO) known as the “End TB Strategy”, attempting to plot a path out of TB by bringing global incidence to “under 100 per million” by 2035.
However, a spanner is being thrown in the WHO’s works: bacteria evolves.
Since the discovery and use of isoniazid and rifampicin in 1952 and 1965 respectively, there’s always been something to fight TB with. However, because bacteria duplicate and change their genetics rapidly, they can become resistant to drugs. In the case of TB, both rifampicin resistance (RR-TB) and rifampicin/isoniazid resistance (MDR-TB) are starting to cause headaches globally, as this chart showing only bacteriologically confirmed cases of RR/MDR-TB shows.
Here’s the same chart with each country expressed individually.
The sheer weight of numbers from China, India and Russia are overwhelming. South Africa, while presenting a large number of total cases, are showing an encouraging downward trend. However, countries such as Indonesia and Philippines are showing unwanted growth.
According to the Global TB Report from 2019, India (27%), China (14%) and Russia (9%) represented 50% of the estimated new RR/MDR-TB cases in 2018. What this doesn’t factor in is population size.
As we can see from this map, the “-stan” countries are copping a heavy burden of RR/MDR-TB cases per 100 thousand population, with Kyrgysztan the most notable. Along with Pakistan, they are also showing severe growth in bacteriologically confirmed RR/MDR-TB cases.
Former Soviet Union countries, as well as South Africa and Indonesia, are highly represented in this map and even more prevalent in the number of extensively drug-resistant TB cases (XDR). XDR-TB is defined as being resistant to “at least four of the core anti-TB drugs” (WHO) – including rifampicin, isoniazid, any fluoroquinolone and at least one of the three second-line injectable drugs. What is important to consider is that regular TB treatment success is 83%. MDR-TB is 54%. XDR-TB is 30%.
Furthermore, an equally important facet to this scenario is if these cases are getting treated.
Perhaps unsurprisingly, due to the sheer magnitude of cases, India and China are head and shoulders above everyone else. China and India alone account for an estimated 28% of the gap between estimated cases and cases enrolled in treatment. However, in addition to total numbers, this shows the percentage of estimated cases who aren’t getting treated. In this regard, some African countries are struggling, except for South Africa.
The next Global TB Report is due out in October.
(Featured Image: Myobacterium Tuberculosis under a Ziehl-Neelsen stain. CDC/DR. GEORGE P. KUBICA)
All data used in this story came from this file, which is a collection of these spreadsheets from the WHO. The place to find these datasets is linked into the charts.
