In 2019, the WHO reported 1.4 million deaths from Tuberculosis (TB); while numbers decreased in 2020, the stastics are deceiving. In fact, many cases in fact went unreported due to the Coronavirus pandemic. TB is still of major concern to scientists who report that 21% fewer people received care for TB in 2020 than in 2019. TB is caused by a bacterium called Mycobacterium tuberculosis (MTB) and can manifest either as active disease or latent infection. TB is one of the leading causes of death worldwide.
How common is Tuberculosis?
Research in 2020 indicated that global TB incidence would increase to levels seen in 2013 as a result of the Coronavirus’ impact on TB diagnosis and treatment. In countries without comprehensive health care infrastructure, TB monitoring and care is always a challenge; the impact of COVID19 has only exacerbated this.
Whilst the WHO notes a slight drop in TB cases as a result of social distancing measures, they also describe that this drop is temporary. The delay put on TB diagnosis and treatment far outweighs any positive impact here. The WHO state that it is “crucial” to strengthen our defence against TB in the years to come.
Two of the key determinants of TB incidence are undernutrition and GDP per capita; modelling suggests that the economic impact of the pandemic could cause a rise in TB cases per year from 2020-2025.
Where do cases of Tuberculosis occur?
Two thirds of TB cases over the past 2 years occurred in 8 countries, but WHO lists 30 countries with high numbers of TB in 2020. The list indicates the percentage of people who developed the disease.
- India (26%),
- Indonesia (8.5%),
- China (8.4%),
- the Philippines (6%),
- Pakistan (5.7%),
- Nigeria (4.4%),
- Bangladesh (3.6%),
- South Africa (3.6%).
2.5% of global cases were in the WHO European Region (2.9%) and WHO Region of the Americas (3%).
(Source Data: Global tuberculosis report 2020 published by WHO)
How does tuberculosis present itself?
According to WHO data, around one third of the world’s population carry TB but do not experience any symptoms. 10% of these people, though, will likely develop symptoms- or active disease-during their lifetime. At this point, they will become capable of transmitting the bacterium.
The most common way active TB presents itself is through lung disease. Symptoms include chest pain, weight loss, weakness, coughing chills and fever. The bacterium is transmitted through coughing, sneezing or spitting.
TB can invade other organs including the kidney, spine and brain, and is then referred to as Extrapulmonary TB.
Miliary TB is a rare form of active TB in which TB bacteria find their way into the bloodstream and spread throughout the body.
Treating TB: The Challenges
Treatment of active TB requires patients to join a treatment program. Today, several medications are available and the chances are high that a patient can be cured so long as they cooperate with the therapy program.
While latest TB infection can only be treated with one drug, active TB infections are treated with a range of antibacterial drugs. Because these only work when the bacteria is actively dividing and because TB bacteria grow very slowly, therapy can take up to 24 months. TB must be treated aggressively and patients may have to start treatment at a hospital.
The biggest challenge with TB therapy is ensuring that patients take anti-tuberculosis drugs on schedule. If not taken on schedule, bacteria gain the opportunity to develop resistance to the drugs. This gives rise to the infamous multi-drug resistance TB (MDR-TB) which remains a public health crisis and health security threat. Currently, around half of the global burden of MDR-TB is in 3 countries- India, China and Russia.
Bacillus Calmette-Guerin (BCG) is currently the only vaccine licensed for use against Miliary TB. It offers effective protection in children, but variable efficacy in adults.
Treating TB: The Future
In order to overcome TB, more effective vaccines and drugs are essential. The WHO and the US and European CDC’s have joined forces to eliminate the epidemic by 2035, reducing 90% of TB cases as compared to the 2015 baseline.
This “End TB Strategy” focuses on the 30 high burden countries worldwide, ensuring that people in these countries have access to high quality diagnosis, treatment and prevention methods.
There are currently 22 drugs and 14 vaccine candidates in Phase I, II or III clinical trials, but to meet the “End TB Strategy” more work will have to be done. In 2020, the WHO launched an implementation research toolkit to support the use of digital technologies in the TB continuum of care.
Dokumeds are proud to play our part in the fight against TB, supporting the development of new medicines and treatment regimens over the last 12 years. One recent addition to the list of anti-TB therapies (delamanid) was approved using the support of Dokumeds.
Dokumeds conducts clinical studies in Africa and Europe, playing an active role in the search for a new TB treatment against MDR-TB. A shorter therapy period would help ensure that patients take all drugs as instructed and this is therefore a key aspect of research.
To find out more about Dokumeds involvement in the fight against TB, click here .