Why India still carries the heaviest burden of neglected tropical diseases

In little over two decades, India has eliminated three neglected tropical diseases (NTDs), sharply reduced cases of visceral leishmaniasis (kala-azar), lymphatic filariasis and trachoma, and driven down deaths from rabies by more than 70%. Mass drug administration campaigns now reach hundreds of millions and technical expertise has deepened.

And yet India continues to carry the world’s greatest burden of neglected tropical diseases.

According to the World Health Organization’s Global Report on Neglected Tropical Diseases 2025, about 42% of the global population requiring at least one NTD intervention lives in India. The figure does not mean India accounts for nearly half of all cases worldwide. “It reflects the country’s large population living in endemic or at-risk settings where public health interventions for one or more WHO-listed NTDs are required for protection, control and/or elimination,” says Payden, acting WHO representative to India.

India has made substantial progress in controlling some of the key NTDs, said S. V. Subramanian, professor of population health and geography at Harvard University. “But the country’s large population base, seasonal surges of mosquito-borne diseases, and the continuing burden of snakebites underline why sustaining momentum is such a challenge.”

How does progress look so far?

Few countries have attempted NTD elimination at the scale India has. Kala-azar cases fell from more than 9,000 in 2014 to just 429 in 2025, according to data from the National Centre for Vector Borne Diseases Control. Dengue deaths dropped from nearly 300 in 2024 to fewer than 100 the following year. Chikungunya cases also halved. India achieved elimination targets for kala-azar at the block level in 2023, and trachoma was officially eliminated through a mix of targeted antibiotic distribution, hygiene interventions and surveillance.

Rabies, long considered intractable, has seen sustained reduction. A recent nationwide survey¹ by the ICMR–National Institute of Epidemiology estimates around 5,700 human rabies deaths annually — down from roughly 20,000 two decades ago — driven largely by expanded access to post-exposure treatment.

“In the last two decades, India has achieved a 75% reduction in rabies deaths,” said Jeromie Thangaraj, a scientist at ICMR–NIE. “Free anti-rabies vaccines in public health facilities have made a major difference.”

These gains reflect years of coordinated effort between national programmes, state health departments, global donors and research institutions. “India’s technical know-how, drug availability and programmatic coverage have all improved,” said S. Subramanian, a consultant at the National Diseases Modelling Consortium at IIT Mumbai.

Why the burden persists

But the same forces that make India’s progress impressive also make elimination precarious.

India’s NTD burden is concentrated among communities living in poverty, in remote rural areas, forested regions, flood-prone districts and sprawling urban informal settlements. Surveillance remains uneven, particularly where health systems are weakest.

“Underreporting and weak surveillance continue to cloud the true burden of NTDs,” said Sanjay Sarin, Asia continental lead at the Drugs for Neglected Diseases initiative. “Cases are often missed in exactly the places where disease risk is highest.”

Data gaps affect everything from resource allocation to outbreak response. The WHO report identifies poor-quality, delayed or incomplete data as a central barrier across the NTD portfolio, particularly for diseases that require sustained monitoring even after elimination targets are met.

Mass drug administration (MDA), a cornerstone of NTD control, faces its own limits. In theory, high coverage can interrupt transmission. In practice, uptake depends heavily on community trust.

“Coverage gaps — even small ones — can significantly reduce programme impact,” said S. Subramanian. “If people don’t trust the system, they don’t participate.”

Urban settings pose a distinct challenge. Informal settlements are often poorly mapped, administratively fragmented and highly mobile, said Himanshu Jayswar, deputy director of the Vector Borne Disease Control Programme in Madhya Pradesh. High density and population movement make both treatment delivery and follow-up difficult.

The risk of reversal

Public-health experts are unanimous that elimination gains are fragile.

“Kala-azar resurged in the 1970s when vector control weakened and surveillance declined,” said Payden. “That history matters.”

Post–kala-azar dermal leishmaniasis (PKDL) remains a particularly stubborn threat. Patients with PKDL often feel well but harbour parasites that can sustain transmission.

“Unless we develop a safe, effective and shorter treatment for PKDL, the risk of resurgence remains very real,” said Shyam Sundar, professor at Banaras Hindu University (BHU) and honorary director of the Kala-Azar Medical Research Center in Muzaffarpur. HIV–visceral leishmaniasis co-infection, though less common, poses an additional long-term risk, he added.

Similar patterns have been observed elsewhere. Localised trachoma resurgence has followed lapses in water, sanitation and hygiene infrastructure or lengthened surveillance intervals after elimination validation. Vector control interruptions, population movement and health-system shocks, including the COVID-19 pandemic, can all undo hard-won gains.

“Elimination is not an endpoint,” Payden said. “Without sustained vigilance, these diseases return.”

Beyond drugs

India’s next phase of progress will depend less on biomedical tools than on systems, experts argue.

Leprosy illustrates the challenge. Although prevalence has declined, early diagnosis remains elusive in hard-to-reach and endemic areas. “The last-mile challenge is detecting cases early,” said P. Narasimha Rao, former president of the Indian Association of Leprologists. Delayed diagnosis prolongs transmission and disability.

“There’s still too much focus on drugs alone,” said Mohan Gupte, former director of ICMR–NIE argued in an article². Case finding, rehabilitation, surveillance and social support must be strengthened alongside treatment, he said.

Trachoma, once widespread, was eliminated through tailored strategies that went beyond antibiotics. “Awareness was key,” said Deepak Mishra of BHU. “Symptoms were often mistaken for routine eye infections.”

The road to 2030

With the global 2030 NTD targets looming, experts emphasise realism over declarations.

“42% does not mean India has failed,” Payden said. “It reflects the scale of the task.”

What matters now, she and others argue, is sustained financing, integration of NTD services into primary healthcare, better real-time data, and deeper community engagement. Trust, especially, remains a decisive variable.

“Targets matter,” Payden said. “But delivery, persistence and system resilience matter more.”