The fight against TB necessitates innovative new strategies to keep pace with the changing face of the epidemic and to capitalise on technological advancements. The first ever United Nations High-Level Meeting on TB in September 2018 called on world leaders to commit to and be accountable for ending TB.
Investment priorities identified at the meeting, for high TB burden countries, include accelerated research and development of new tools and technologies, such as improved diagnostics, therapies and vaccines, and increased resources to implement TB programs. Due to huge improvements in TB diagnosis and treatment, an estimated 54 million lives were saved between 2000 and 2017. The rate of new infections is declining at less than 2% per year, according to the World Health Organisation (WHO), but this needs to accelerate to 5% annual decline if we are to reach the 2020 milestones of the End TB Strategy. Globally, in 2017, there were 10 million newly infected TB cases and 1.6 million deaths from the disease. Two thirds of the new infections were in eight countries: India (27%), China (9%), Indonesia (8%), the Philippines (6%), Pakistan (5%), Nigeria (4%), Bangladesh (4%) and South Africa (3%).
Technological breakthroughs are needed to drive the infection rate down. These can only come from intensified research and development. According to WHO’s Global TB Report 2018, research priority areas include a vaccine to lower infection risk, a vaccine or new drug to reduce the risk of TB disease in the latently infected, rapid diagnostics for use at the point of care, and simpler, shorter drug regimens for treating TB disease. There are developmental progresses, with 20 drugs, a number of treatment regimens and 12 vaccines being tested in clinical studies. Countries have also been exploring the use of innovative tools to improve treatment adherence.
The Genexpert test, internationally endorsed in 2010, was a major breakthrough in TB diagnostics. This molecular test detects TB bacteria using a sputum sample, while simultaneously testing for resistance to Rifampicin, a first line drug used the treat TB. Results are available in under two hours. India, South Africa and Swaziland are some of the countries that introduced countrywide Genexpert testing. Genexpert paved the way for investment into TB diagnostics. However since its development, few other diagnostic technologies have materialized.
Resistance to first line TB drugs occurs when TB medicines are incorrectly prescribed or when patients do not adhere to their treatment. Multidrug-resistant TB (MDR-TB) is a form of TB that arises when TB bacteria become resistant to isoniazid and rifampicin, the two primary anti-TB drugs. Of the estimated 558,000 new drug resistant TB cases in 2017, 82% had MDR-TB, with India, China and the Russian Federation bearing the highest burden. Current treatment regimens for MDR-TB often consist of many large pills or injectable treatments, which can take up to 2 years to complete. In countries with high HIV and TB co-infection, the high dosage of pills discourages patients from adhering to their treatment. Injectable treatments have also been associated with severe side effects, including irreversible hearing loss, in some patients. Shorter 9-12 month treatment regimens have been introduced in several countries. Bedaquiline, a recently developed and approved drug to treat MDR-TB, is being used in 62 countries. South Africa has the highest bedaquiline uptake, and recently announced that the drug will be part of the standard recommended treatment regimen for rifampicin-resistant tuberculosis.
Recently, technology has also given rise to a range of mobile apps aimed at promoting treatment adherence, increasing TB knowledge, better case reporting as well as addressing smoking cessation. The Government of India developed a mobile app, called NIKSHAY, that links to the central database of all TB patients in the country. It allows healthcare workers to report and track all TB patients and monitor their treatment. The piloted TB Mitra mobile app provides users in India with information on TB symptoms and maps their closest diagnostic or treatment centre. The use of geospatial information systems (GIS) methods is being explored in high burden communities in South Africa for tracking and prioritising patients.
However there is a dire need for developing more innovative technologies to win the fight against TB. WHO’s End TB Strategy calls for new tools to be introduced no later than 2025. In an interview given recently to Citizen News Service (CNS) Dr Soumya Swaminathan, Chief Scientist at WHO had categorically stated that, “Without new tools elimination goal of TB is not going to be possible. And these new tools would mean a point of care rapid diagnostic test which can be performed in the field settings to screen as well as to diagnose TB; a treatment combination of drugs that would cure TB in a short period, say 1-2 months; a better vaccine for TB and a better detection and treatment strategy for latent TB. These are the identified gaps where R&D is needed. The whole concept of eliminating TB (by 2030) is based on the fact that we are going to have some of these tools available as we go forward”.
As per WHO's Global TB Report 2018, global funding for prevention, diagnostics and treatment was $ 6.9 billion in 2018, with the majority of funding (86%) coming from domestic sources. Funding for TB research and development has also increased in recent years, peaking at US$ 724 million in 2016. However, this is only 36% of the estimated requirement of US$ 2 billion per year. Without plugging this funding gap for TB R&D to have new and improved tools for TB care and control, a TB free world is likely to remain a distant dream.
Ronel Sewpaul, Citizen News Service - CNS
April 12, 2019