As per the Global Tuberculosis Report 2022, eight countries account for two-thirds of the disease cases globally. India tops the list with 28% of all cases; a little over 21 lakh TB cases were notified in the country in 2021.
Tuberculosis, which is caused by the bacterium Mycobacterium tuberculosis, mainly affects the lungs. Though the United Nations Sustainable Goals have set the target of ending the TB pandemic by 2030, the road ahead seems to be challenging.
Multidrug-resistant TB (MDRTB) and many affected people not taking their medications as prescribed are among the chief concerns, experts say.
TB prevalence in India
According to Dr Bornali Dutta, director, department of respiratory and sleep medicine, Medanta – The Medicity, Gurugram, Haryana, the need is to understand the fact that incidence and prevalence of TB in India is very high. “With the world’s [highest] burden of TB [being in] in India, almost everyone will be at risk,” says Dutta, who also heads Medanta’s drug-resistant TB centre.
Talking about pulmonary TB, Dr Ravindra Mehta, chief of pulmonology, Apollo Specialty Hospitals, Bengaluru, says the typical symptoms are persistent cough, weight loss and lack of appetite. Some affected people might even cough up blood.
In some cases, TB could manifest as chest pain. “In extra pulmonary TB, there could be pain in the abdomen,” he says.
Drug-resistant TB — a major worry
WHO terms drug-resistant TB (DRTB) a public health threat. In DRTB — a form of antimicrobial resistance — the disease-causing bacteria is resistant to rifampicin and isoniazid, the primary anti-TB drugs.
According to Dr K Vinodini, senior consultant microbiologist, Neuberg Diagnostics, Chennai, the biggest challenge is the early diagnosis of TB and detection of its drug-resistant pattern.
She says the drug-resistant pattern is not fully addressed by the available molecular tests. In such cases, a culture-based phenotypic drug susceptibility testing method — the gold standard for DRTB — is used. “It has a longer turnaround time,” said Dr Vinodini.
In 2021, India (26%) had the largest share of MDRTB — a type of DRTB — cases in the world, followed by the Russian Federation (8.5%), Pakistan (7.9%).
Possible side-effects
Dr Dutta recalls the case of a 26-year-old woman from Punjab who was treated for MDRTB in 2019. The woman had already been treated for TB for a year but the disease was inadequately diagnosed, says Dr Dutta. The TB had spread to her lymph nodes too.
“She was suffering from MDRTB,” says the doctor. “We monitored her condition closely and she was put on injectable drugs. While being affected with TB in the prime of life can be depressing, anti-TB drugs too can cause depression as a side-effect,” says Dr Dutta.
Since the woman had also developed joint pain, her medicines had to be tweaked. She was on clofazimine, an anti-TB drug known to cause pigmentation of the skin. The result was that the fair-skinned woman became darker.
“She got completely cured after 18 months of monitoring and treatment,” says Dr Dutta. “She got back her complexion too.”
MDRTB in children
According to Dr Nitin Shah, HOD, pediatrics, PD Hinduja Hospital, Mumbai, MDRTB cases make up 10%-15% of the total number, especially in cities like Mumbai. “It’s a terrible problem,” said Dr Shah. “It’s no more a problem of the underprivileged. We have seen MDRTB even in kids from high-rise buildings. At any given point of time, there would be 15-20 kids with MDRTB under my treatment. Non-adherence to the treatment regimen in some TB-affected persons is a concern. They potentially spread it to others.”
‘Completely curable’
Dr Dutta says that tuberculosis is a completely curable disease. “It is an infection for which very good treatment is available and it is completely curable,” she says. “[But] that’s only if the person completes six months of the treatment regimen and does not cut it short. The problem [in many cases] is that the infected persons follow [the regimen] for two months, feel [better] and stop. If the treatment is discontinued, TB will come back for sure.”
While adherence to the treatment regime is a major challenge before the WHO’s ‘End TB Strategy’, Dr Mehta says educating infected people, engaging them and clearing doubts can help. “Explaining the downside of non-compliance to medicines is a must,” he says. “Infected persons must visit the doctor for regular and timely follow-ups. In case of non-compliance, they are put under the government monitoring system,” said Dr Mehta.
Under the WHO-endorsed Directly Observed Therapy, a person infected with TB is monitored by healthcare workers and families to ensure adherence to TB drugs.
Why latent TB is a concern
Another challenge is latent TB, where the bug gets into the system but is localised — that is, not spreading or causing any trouble. “It’s like a criminal in the jail and not rampant in the community,” says Dr Mehta. “If a criminal is kept in jail and they reform, they won’t create havoc. But if the criminal is released, there will be havoc, and that’s latent TB. Unless screened, latent TB won’t be known — and there is no screening done for latent TB.”
According to Dr Dutta, about 40% of the Indian population suffers from latent TB infection. “It basically means that we have been exposed to TB but our immune system has kept it in control,” Dr Dutta says. She adds that if any individual with latent TB undergoes a period of immune suppression, there will be reactivation of bacteria and the TB will flare up.
Takeaways
- Tuberculosis is caused by Mycobacterium tuberculosis, which mainly affects the lungs.
- In cases of drug-resistant TB, affected people develop resistance against the primary line of treatment.
- However, with strict adherence to the treatment regimen, TB can be completely cured.