Why is the mortality rate from tuberculosis (TB) high in India despite being a curable disease?

Why Tuberculosis Remains a Major Cause of Death in India Despite Being Curable

Despite tuberculosis (TB) being a curable disease, approximately two-thirds of drug-resistant TB cases in India go undetected and therefore untreated, leading to continued high mortality rates. 1

Key Factors Contributing to TB Mortality in India

Detection and Diagnosis Challenges

• Only about one-third of drug-resistant TB cases are detected and treated annually in high-burden countries like India, leaving the majority of cases undiagnosed 1
• In 2020, there was a 22% decrease in detection of drug-resistant TB cases globally, with only 157,903 new cases detected, reflecting gaps in diagnostic capacity 1
• The COVID-19 pandemic significantly disrupted TB services, resulting in decreased case notifications and increased TB deaths 1

Treatment Access and Completion Issues

• Approximately 2 in 3 individuals who develop multidrug-resistant/rifampicin-resistant TB (MDR/RR-TB) each year do not receive appropriate treatment 1
• Treatment success rates for MDR/RR-TB, while improving, remain suboptimal at 59% globally (as of 2018 data) 1
• In India, studies have shown declining favorable treatment outcomes for MDR-TB patients over time 2

Socioeconomic and Demographic Risk Factors

• Patients with age ≥35 years, male sex, and undernourishment (BMI <18.5) at treatment initiation have significantly increased likelihood of unfavorable MDR-TB treatment outcomes 2
• Socioeconomic disadvantages, political unrest, and limited drug availability contribute to treatment access barriers 1
• Poor primary healthcare infrastructure in rural areas of many Indian states limits effective TB control 3

Drug Resistance: A Major Challenge

• Drug-resistant TB is classified into different categories based on resistance patterns, with extensively drug-resistant TB (XDR-TB) being the most challenging to treat 1
• MDR-TB (resistance to isoniazid and rifampicin) and XDR-TB (resistance to rifampicin, fluoroquinolones, and other priority drugs) carry worse outcomes 1
• Experience with XDR-TB treatment in India has not been encouraging, with high rates of mortality and treatment failure 4

Diagnostic Advancements and Challenges

• Newer rapid diagnostic methods like GeneXpert, whole genome sequencing, and Myc-TB offer solutions for rapid detection of resistance but are not universally available 1
• Molecular testing is increasingly the method of choice for diagnosis and assessment of drug-resistant mutations for TB 1
• Testing for rifampicin resistance has improved globally (71% of bacteriologically confirmed cases), but testing for fluoroquinolone resistance remains significantly lower at around 50% worldwide 1

Treatment Improvements

• By the end of 2020,109 countries were using bedaquiline and 90 countries were using modified regimens to improve treatment outcomes 1
• The availability of new TB drugs and shorter treatment regimens have been recommended for the management of drug-resistant TB 1
• Treatment success rates for MDR/RR-TB have improved from 50% to 59% between 2012 and 2018 globally 1

Systemic Challenges in India

• Unregulated private healthcare leading to widespread irrational use of first-line and second-line anti-TB drugs 3
• Corrupt administration and lack of political will impede effective TB control programs 3
• The DOTS (directly observed treatment-short course) program in India, while extensive, faces implementation challenges 3

Path Forward

• Control of TB and elimination will only occur if cases are detected, diagnosed, and treated promptly 1
• Active case finding (ACF) in addition to passive case finding may improve outcomes in patients with pulmonary TB and reduce transmission in high TB prevalence populations 1
• Strategies for TB diagnosis in low-income countries should focus on improved case detection rather than solely on diagnostic testing 1

To reduce TB mortality in India, addressing the detection gap of the approximately two-thirds of drug-resistant cases that go undetected each year must be prioritized, alongside improving treatment access and success rates through newer drugs and shorter regimens.