Global insights can accelerate India’s journey towards the elimination of lymphatic filariasis as a public health problem

Abstract

India has set an ambitious target to achieve the elimination of lymphatic filariasis (LF) as a public health problem by 2027, 3 years ahead of the global target. Achieving this goal demands accelerated progress and evidence-based strategies. This review synthesises insights from the policies and interventions of 21 countries that achieved LF elimination in the past decade (2015–2024). Key lessons for India include integrated disease management, tailored drug distribution, capacity building, targeted outreach to migrant and never-treated populations and enhanced morbidity management strategies. It also highlights the role of robust social mobilisation, vector control strategies and strategic deployment of digital technologies. Tailoring these global practices to India’s diverse contexts can address the existing challenges and strengthen last-mile elimination efforts. Moreover, these insights provide a valuable blueprint for other endemic nations striving to achieve similar goals.

Summary box.

• By 2024, 21 countries had successfully eliminated lymphatic filariasis (LF) as a public health problem, reflecting significant global progress.

• India bears the highest LF burden globally, accounting for ~62% (404.3 million) of the at-risk population, with 619 000 lymphoedema and 150 708 hydrocele cases.

• Suboptimal mass drug administration coverage, treatment gaps among migrants, high-risk and urban populations and inadequate morbidity management remain key barriers to LF elimination in India.

• India can accelerate LF elimination by adapting proven strategies from successful countries, including integrated disease management, tailored drug delivery, dedicated morbidity care units, strengthened vector control, robust community engagement and technology-enabled monitoring.

• Targeted outreach to mobile and never-treated populations is essential for sustainable elimination in India.

Introduction

Lymphatic filariasis (LF) is a parasitic infection and a leading cause of chronic disability in tropical regions, with symptoms including lymphoedema and hydrocele.¹ The disease is caused by three species of nematode parasites—Wuchereria bancrofti, Brugia malayi and Brugia timori—and is transmitted by mosquitoes belonging to the Anopheles, Culex, Aedes and Mansonia species.² Globally, 657 million people in 39 countries are at risk, with 36 million suffering chronic symptoms.³ The WHO’s South-East Asian Region (WHO-SEAR) bears the highest burden of the global at-risk population. India alone accounts for~62% (404.3 million people) of this at risk group and reports 619 000 cases of lymphoedema and 150 708 hydrocele cases.⁴

The Global Programme to Eliminate Lymphatic Filariasis (GPELF) was launched in 2000 to eliminate LF as a public health problem (EPHP) in 73 endemic countries by 2020. It is built on two core strategies: mass drug administration (MDA) in at-risk populations to interrupt transmission and morbidity management and disability prevention (MMDP) for those already affected. MDA involves the annual distribution of anthelminthic drugs to all individuals aged 2 years and above in endemic areas, regardless of infection status, as many may be asymptomatic carriers of microfilaria (mf). The choice of regimen- single-drug (diethylcarbamazine (DEC)), double-drug (ivermectin with albendazole or DEC with albendazole (DA)), or triple-drug therapy (ivermectin, DEC and albendazole (IDA)) depends on the co-endemicity of LF with other filarial diseases. Although standard MDA regimens do not kill adult worms, they primarily target mf, thereby interrupting transmission through mosquito vectors. The drugs act to reduce the density of mf circulating in the bloodstream. For safety reasons, pregnant women, children under two and individuals with severe illnesses are excluded from treatment. To break the transmission cycle, sustained MDA coverage of at least 65% of the eligible population is required for five to six consecutive years with DA, or two to three annual rounds when using IDA. By 2023, more than 9.7 billion treatments had been delivered across 71 countries.⁴ The GPELF target has since been extended to 2030, aiming for EPHP in at least 58 of the 72 endemic countries.⁵

The WHO’s 2016 guidelines set criteria for validating EPHP, focusing on transmission interruption and morbidity management.⁶ To stop MDA, countries must pass three Transmission Assessment Surveys (TAS), a standardised method using blood tests to confirm interruption of transmission. For areas treated with the DA, these surveys test school-aged children (6–7 years) for mf or circulating filarial antigens (CFA). To qualify, countries must demonstrate mf prevalence below 1%, antigen (Ag) prevalence under 2% in children or antibody prevalence below 2% for Brugian filariasis.⁷ Additionally, effective management of lymphoedema and hydrocele cases is required before submitting an elimination dossier.

The global momentum towards LF elimination shows significant progress. As of 2024, 38 of the 39 countries requiring MDA had initiated treatment, with Gabon as the only exception. Overall, the population requiring MDA has declined to 58.6% since the programme’s inception.⁴ From 2015 to 2024, 21 countries have successfully eliminated LF (table 1).⁸ In Africa, Togo was the first country to eliminate LF as a public health problem in 2016, followed by Malawi in 2020. Egypt and Yemen reached this milestone in the Eastern Mediterranean in 2017 and 2020, respectively. In SEAR, five countries have eliminated LF: Sri Lanka in 2015, the Maldives in 2015, Thailand in 2017, Bangladesh in 2023 and Timor-Leste in 2024. In the Western Pacific, 11 countries, including Vanuatu, Cambodia, Niu, Cook Islands, Tonga, Marshall Islands, Wallis and Futuna, Palau, Kiribati, Vietnam and Lao People’s Democratic Republic (PDR) reached elimination by 2023. Brazil achieved this in 2024 in the Americas (figure 1).

Table 1. List of countries by WHO region which eliminated LF as a public health problem from 2015 to 2024.

WHO region	Country	Parasite	Primary vector	Treatment	No of MDA rounds	Coverage (final round)	Year of EPHP
Africa	Togo	W. bancrofti	Anopheles	IVM+ALB	10	82.6	2016
	Malawi	W. bancrofti	Anopheles	IVM+ALB	6	83	2020
Americas	Brazil	W. bancrofti	Culex	DEC	13	69	2024
Eastern Mediterranean	Egypt	W. bancrofti	Culex	DEC+ALB	14	92.8	2017
	Yemen	W. bancrofti	Culex	IVM+ALB	10	82	2020
South-East Asia	Sri Lanka	W. bancroftiB. malayi	Culex	DEC+ALB	7	84	2015
	Maldives	W. bancrofti	Culex	DEC+ALB	6	78	2016
	Thailand	W. bancroftiB. malayi	AnophelesMansonia	DEC+ALB	11	93.4	2017
	Bangladesh	W. bancrofti	Culex	IVM+ALB	18	76.2	2023
	Timor-Leste	B. timori	Anopheles	DEC+IVM+ALB	16	76	2024
Western Pacific	Vanuatu	W. bancrofti	AnophelesAedes	DEC+ALB	7	85	2015
	Niue	W. bancrofti	Aedes	DEC+ALB	7	85	2015
	Cook Islands	W. bancrofti	Aedes	DEC+ALB	8	87.3	2015
	Cambodia	W. bancrofti	Anopheles	DEC+ALB	5	84.6	2015
	Tonga	W. bancrofti	Aedes	DEC+ALB	6	92	2016
	Marshall Islands	W. bancrofti	Culex	DEC+ALB	7	65	2016
	Wallis and Futuna	W. bancrofti	Aedes	DEC+ALB	8	66	2018
	Viet Nam	W. bancroftiB. malayi	CulexMansonia	DEC+ALB	7	86.3	2018
	Palau	W. bancrofti	Culex	DEC+ALB	4	Not available	2018
	Kiribati	W. bancrofti	Culex	DEC+ALB	13	91	2020
	Lao PDR	W. bancrofti	Culex	DEC+ALB	10	87	2023

ALB, Albendazole; B. malayi, Brugia malayi; B. timori, Brugia timori; DEC, diethylcarbamazine ; EPHP, eliminate LF as a public health problem; IVM, Ivermectin; LF, lymphatic filariasis; MDA, mass drug administration; PDR, People's Democratic Republic; W. bancrofti, Wuchereria bancrofti.

Figure 1. World map depicting endemic countries where lymphatic filariasis was eliminated as a public health problem at different time points (2015–2024). PDR, People's Democratic Republic.

These successes offer valuable lessons for India as it advances its efforts to eliminate LF. In India, W. bancrofti is responsible for 98% of infections, transmitted primarily by Culex mosquitoes.^{9 10} While longitudinal nationwide data on LF prevalence trends are not publicly available, individual district-level mf surveys indicate considerable heterogeneity. In Nagpur district, Maharashtra, serial surveys conducted since 2004 have documented a marked decline in mf prevalence, from 4.9% to <1% by 2015. Similarly, cross-sectional surveys conducted between 2014 and 2021 in districts of Madhya Pradesh, Assam, the Andaman Islands and Karnataka reported mf rates ranging from 3.2% to 6.9%.11,14

Efforts towards elimination were initiated by 2004, initially targeting 202 districts with MDA using DA. In 2017, a community-based randomised controlled trial (RCT) by the Indian Council of Medical Research-Vector Control Research Centre (ICMR-VCRC) established the safety and efficacy of the triple-drug regimen (IDA), leading to its adoption in the national programme in 2018.¹⁴ That same year, India launched an Accelerated Plan for Elimination of LF, aiming for LF EPHP by 2020, in line with WHO-SEAR’s strategic framework. The plan outlined three key objectives and 13 action points, including: accelerating transmission interruption through enhanced preventive chemotherapy, providing a minimum package of care to those with chronic disease and preparing for the LF elimination validation dossier. In 2023, India introduced the Enhanced Strategy for LF Elimination, adopting a more holistic approach. This included biannual mission-mode MDAs, that is, carrying out MDA two times a year so as to cover the endemic areas in a phased manner, expanded MMDP with emphasis on early diagnosis and treatment, integrated vector control through surveillance and management, high-level advocacy and the use of digital platforms and alternative diagnostic tools.¹⁵ Despite these efforts, LF remains endemic in 348 districts across 20 states, with 159 districts still undergoing MDA.¹⁶ The average national MDA coverage reported by the programme in 2023 is 81.8% (figure 2),⁸ though significant variation exists across endemic districts. This paper explores the key enablers from countries that have eliminated LF in the past decade to support India’s elimination strategies and help India achieve its goal. Lessons from these countries can offer critical insights for India to strengthen its LF programme and help meet the 2027 target as pledged by the Ministry of Health and Family Welfare.¹⁶

Figure 2. MDA coverage by Indian lymphatic filariasis elimination programme against the eligible population from 2001 to 2023. Source: WHO-The Global Health Observatory Data 2024. MDA, mass drug administration.

Barriers to achieving LF elimination in India

Suboptimal MDA coverage and compliance

Suboptimal MDA coverage, often falling below the effective coverage threshold of 65%, significantly hampers India’s LF elimination efforts.^{9 17} In 2023, 63 districts were under the MDA-IDA, with many requiring additional rounds due to insufficient coverage. Coverage Evaluation Surveys (CES) conducted by the national programme across 11 districts in 2023 found an average 71% coverage, ranging from 60% to 90%.¹⁸ Independent CES in districts such as Yadgir and Nagpur in 2015 and 2019 reported low coverage rates of 56.1% and 48.5%, respectively.^{19 20} In addition, CES in four districts of Uttar Pradesh (U.P.) reported coverage ranging from 49.8% to 87.9%.²¹ Subpopulations, such as the elderly, exhibit even lower compliance.²² Key factors driving underperformance include drug refusal, absenteeism, fear of side effects and fatigue from repeated MDA.23,25 Issues with drug delivery, such as inappropriate timing of drug distribution, particularly when the community is absent due to seasonal migration, agricultural activities or local festivals, lead to non-compliance, ranging from 4.7% to 33.6%.^{26 27} Additionally, the high pill burden required for MDA, especially with varying dosages by weight and age, often discourages adherence.²⁷ Although the programme has taken several steps, including the Directly Observed Treatment (DOT), healthcare workers training and involving local medical colleges in CES,⁹ inconsistent DOT application, healthcare worker overburdening and misinformation from private practitioners weaken outcomes.^{28 29}

Treatment gaps in ineligible, migrant and never-treated populations

Certain demographic groups, such as migrants, pregnant women, young children and the elderly or chronically ill, face treatment gaps, leaving them untreated and at risk.²⁵ With approximately 600 million internal migrants in India and 2–2.5% of the endemic population migrating annually, many miss MDA rounds due to mobility.^{30 31} The never-treated population, defined as eligible individuals who have never participated in any MDA rounds, compounds the issue.³² For instance, studies in Nagpur and Yadgir, 18% and 16.5% of eligible individuals, respectively, reported never receiving MDA.^{22 33} If infected, these untreated individuals can serve as reservoirs and can continue to sustain transmission. Similarly, pregnant women, chronically ill and young children are excluded due to their ineligibility as per programme guideline. However, studies indicate that pregnant women with mf can act as disease reservoirs.³⁴ Therefore, these mothers need to be followed-up thoroughly after delivery and administered drugs as per norms. Similarly, individuals with advanced age are frequently excluded from treatment due to safety concerns, which may be unfounded in several instances.²² Although the programme implements mopping-up rounds to reach missed individuals, targeted follow-ups and tailored treatment plans are essential for these groups.

Lymphatic filariasis in urban areas

Urban areas face unique challenges due to complex demographics and higher non-compliance with MDA.³⁵ Mistrust of the drugs is reported as a key issue; as urban residents often prefer doctor-prescribed medications. Urban residents are often sceptical about the safety of drugs delivered by community health workers, especially when they are asymptomatic.³⁶ This mistrust and care preferences reduce compliance with MDA in this setting. Notably, MDA coverage is much lower in urban districts (39%) compared with rural districts (81%).³⁷ Additionally, urban-specific factors such as high population density, mobility, gated communities and overcrowded informal settlements pose operational difficulties for the effective execution of MDA.⁹

Gaps in morbidity management and disability prevention services

Despite measures being taken up to improve the implementation of MDA in endemic districts, gaps remain in MMDP. In India, the minimum package of care for patients with lymphoedema is largely aligned with the WHO’s Essential Package of Care (EPC). This includes treatment for episodes of adenolymphangitis, access to hydrocele surgery and distribution of self-care kits for lymphoedema management. While the programme aims for 100% coverage, poor execution and insufficient intersectoral coordination hinder progress.^{38 39} For instance, only 167 276 MMDP kits were distributed in 2022, covering less than one quarter of the known patients with lymphoedema.⁴⁰ These kits, containing hygiene essentials like a tub, mug, bucket, towel, soap and antifungal cream, are essential for limb care. Hydrocele management remains inadequate due to insufficient training in hydrocelectomies, as well as stigma and fear around the treatment among patients. Primary health centres, responsible for MMDP, are often overburdened.⁴¹ The success of the minimum package of care or home-based care depends on the skills of the healthcare staff. Additionally, patients’ challenges, such as socioeconomic issues and comorbidities further complicate MMDP.⁴² Women with lymphoedema experience compounded disadvantages due to entrenched gender norms, economic inequities and psychological stress.⁴³ Although the Government of India has notified lymphoedema as a disability in 2018, the benefits have not effectively reached patients.³⁸ Establishing specialised MMDP units such as the ICMR-VCRC filariasis clinic, which offers treatment, physiotherapy, counselling and e-consultation, to the patients from the region can improve the quality of care for chronic patients, espcially those who are in stage III and IV. The clinic serves nearly 400 patients, many travelling from distant places, including neighbouring states, due to inadequate service locally.⁴⁴ To improve care and achieve WHO validation of EPHP, resources must be reorganised to strengthen the MMDP programme in the country.

Challenges in LF surveillance

LF surveillance faces challenges, especially reliance on night blood surveys. These surveys require collecting blood samples from individuals at night (typically from 20:00 onwards) when mf are present in the peripheral blood. However, this method was often met with community resistance due to its timing and invasiveness.²⁵ These mf surveys need to be done 6–9 months after the MDA rounds to understand the clearance of mf. Alternative diagnostic methods, such as Ag-detection tests including the WHO recommended Filariasis Test Strips (FTS) are limited by timely availability and technical disadvantages. The adoption of alternative methods like the STANDARD Q Filariasis Antigen Test (QFAT), validated by ICMR-VCRC, could help mitigate this gap. QFAT has demonstrated high sensitivity (95.5%) and specificity (99.7%) for detecting the W. bancrofti Ag and is considered a cost-effective and promising tool for field-level surveillance.⁴⁵

Key strategies adopted by successful countries by year of elimination

Cambodia (2015)

LF in Cambodia was caused by W. bancrofti and transmitted by Anopheles mosquitoes, placing nearly 500 000 people at risk. The key elimination strategy, MDA, was carried out from 2005 to 2009 using the DA regimen, achieving 84.6% coverage in the final round. Baseline mf was 1.8%, dropping to <1% after two rounds of MDA. Strong community engagement played a crucial role, mobilised through village heads, school teachers and health workers. Treatment adherence was reinforced through a DOT strategy. The health system was strengthened through training and incentivising health workers, who supported lymphoedema and hydrocele patient mapping and management. Complementary programmes, such as insecticide-treated nets (ITNs) for malaria and MDA for soil-transmitted helminths (STH), supported LF efforts.⁴⁶

Cook Islands (2015)

In the Cook Islands, W. bancrofti was transmitted by Aedes mosquitoes, putting nearly 18 000 people at risk of LF. MDA was implemented from 2000 to 2007 using the DA, and 87.3% coverage was achieved. LF was endemic across all islands, with a baseline average Ag prevalence of 8.6%, which declined to 0.2% after six rounds of MDA. Drug distribution was highly tailored to local contexts, involving house-to-house visits, workplace visits, schools, public meetings and child welfare clinics. The DOT strategy ensured treatment adherence, while mass media and church campaigns raised LF awareness in the community. Partnerships with pharmaceutical companies facilitated drug procurement. A ‘test and treat’ approach was implemented for targeted testing and treatment in some islands.⁴⁷

Maldives (2015)

The Maldives was the first country in the WHO-SEAR to achieve EPHP. In the Maldives, W. bancrofti, transmitted by Culex mosquitoes caused LF, placing around 19 000 people at risk. WHO-supported surveys in 1951 in 34 inhabited islands found that 37% of the population were either infected or with clinical signs of LF. Five rounds of MDA were conducted, using the DA, achieving a coverage rate of 77.7%. Community mobilisation, led by island chiefs and health workers, was key. A national regulation in 1996 mandated mf screening for military recruits and students travelling abroad, enhancing case detection.⁴⁸

Niue (2015)

In Niue, W. bancrofti transmitted by Aedes mosquitoes posed a risk of LF to nearly 2000 people. MDA took place from 2000 to 2006 using a DA regimen, with 85% coverage achieved in the final round. Baseline Ag prevalence was 3.1%, which declined to 0.2% after four rounds of MDA. Centralised drug distribution at community centres and DOT reinforced compliance. Active screening and treatment targeted at missed populations. A post-MDA survey identified and treated all positive cases and public–private partnerships (PPP) facilitated drug donations and testing kits. The island’s small population, natural climatic variability and vector control efforts were also critical.⁴⁹

Sri Lanka (2015)

W. bancrofti, transmitted by Culex mosquitoes, caused LF in Sri Lanka, placing over 10 million people at risk. MDA was implemented from 2001 to 2007 using the DA regimen. The programme achieved 84% coverage in its final round. The national mf rate was 0.2% in 2001 at the start of the elimination programme, and declined to 0.06% by 2016. Tailored social mobilisation strategies, supported by WHO’s Communication for Behavioural Impact (COMBI) project, boosted MDA acceptance and coverage. Although vector control was not the primary strategy, it was selectively applied in high-transmission areas to complement MDA efforts. Vector surveillance was strengthened through molecular xenomonitoring. MMDP services were channelled through a network of specialised filarial clinics scattered in endemic regions, offering free treatment for acute and chronic conditions, wound care supplies and personalised health education through one-on-one counselling, demonstrations and illustrated materials in the local languages. The widespread use of bed nets, driven by mosquito nuisance, further complemented the programme’s success.⁵⁰

Vanuatu (2015)

In Vanuatu, W. bancrofti was transmitted by Anopheles mosquitoes, which also carry malaria. Approximately 200 000 people were at risk of infection. MDA was conducted from 2000 to 2006 using a DA regimen, with an average coverage of 81%. The mf prevalence at baseline was 4.8%, which declined to 0.16% after five rounds of MDA. The programme’s success was largely driven by culturally tailored campaigns and strong community engagement, led by trusted local health workers and community leaders. Complementary malaria control measures, including ITNs and indoor residual spraying (IRS), further strengthened the elimination.⁵¹

Marshall Islands (2016)

In Marshall Islands, W. bancrofti was transmitted by Culex mosquitoes. The primary elimination strategy, MDA, was conducted from 2003 to 2009 using the DA regimen, achieving a final coverage of 68%. At baseline, only two islands had a high LF prevalence, with antigenaemia rates of 44.2% and 29.1%, respectively. MDA was targeted specifically at these islands, and after five rounds, Ag prevalence dropped to <1%. The programme emphasised robust social mobilisation, health education and health system strengthening, with targeted campaigns in high-endemic areas to ensure coverage. Partnerships with Pacific countries reinforced the programme’s success.^{52 53}

Togo (2016)

W. bancrofti, transmitted by Anopheles mosquitoes, caused LF in Togo. Approximately 1.2 million people were at risk. Between 2000 and 2009, the country implemented MDA using the DA, achieving an average 82.6% coverage. Baseline mf prevalence ranged from 1% to 36%. Following six to seven rounds of MDA, mf prevalence fell to <1% in all endemic areas. A key factor was the opportunistic integration of LF control with the national onchocerciasis programme, which had been distributing ivermectin since the 1980s. The National Neglected Tropical Disease (NTD) programme further strengthened effectiveness by integrating LF control with efforts against co-endemic diseases like STH and schistosomiasis in targeted areas. Collaboration with the national malaria programme also played a key role. Community participation was strengthened through innovative mass media campaigns. Togo became the first country to establish a nationwide LF surveillance system in 2006, supported by the Centre for Disease Control and Prevention (CDC), which enhanced tracking and identification of active infections. Numerous laboratories across the country participated in the surveillance, providing regular monthly reports, further solidifying the programme’s success.⁵⁴

Tonga (2016)

In Tonga, W. bancrofti, transmitted by Aedes mosquitoes, placed over 100 000 people at risk of infection. MDA was conducted from 2001 to 2006 using the DA regimen, achieving an impressive 92% coverage in the final round. The baseline Ag prevalence rate was 2.7%, which declined to 0.34% after five rounds of MDA. Community mobilisation was a cornerstone of the programme, supported by local leaders, religious figures and Non Governmental Organisations (NGOs) ensured high coverage. Drugs were distributed at community centres such as schools and churches, enhancing programme acceptance and access. In churches, notices on MDA were read out by priests and encouraged the communities to participate. Targeted efforts were made to reach missed populations, supported by mass media campaigns. The DOT strategy ensured treatment adherence, and PPP was leveraged for drug procurement.⁵⁵

Egypt (2017)

W. bancrofti was the causative parasite for LF in Egypt, transmitted by Culex mosquitoes, which posed a risk to approximately 2.7 million people. MDA began in 2000 using DA, achieving 92.8% coverage in its final round. The national baseline mf prevalence was 10.8%, which decreased to 0% by the fifth MDA round. Social mobilisation, including advocacy efforts through inter-ministerial collaboration and engagement of local and religious leaders, supported community participation in MDA. Post-MDA surveillance was strengthened using molecular xenomonitoring. MMDP were prioritised by systematic patients’ registration and morbidity management training. Patients were provided with self-care booklets in Arabic along with hygiene kits. The country built strong partnerships with domestic bodies at both central and peripheral levels. Universities played a key role in operational research, further supporting the national elimination effort.⁵⁶

Thailand (2017)

In Thailand, W. bancrofti and B. malayi caused LF, transmitted by Anopheles and Mansonia mosquitoes. The disease posed a significant public health challenge, affecting an estimated 170 000 people. MDA began in 2002 using the DA regimen, achieving 93.4% coverage in the final round. WHO surveys during 1951 reported an average mf rate of 21.0%. A unique aspect was zoonotic transmission, with domestic cats identified as carriers of B. malayi. This prompted integrated control strategies that included active surveillance and treatment of infected cats with ivermectin. These efforts reduced the prevalence to 0.8% by 2015, effectively interrupting human transmission. Given the country’s long borders with Myanmar and the large influx of migrants, there were concerns about LF reintroduction. To address this, mandatory LF screening for migrants was implemented to strengthen case detection. Compliance with treatment was ensured through the DOT method and robust community mobilisation, including large-scale awareness events held during ‘Filaria Week’ in endemic villages. The programme also benefitted from mutisectoral collaboration among health, labour and animal control sectors strengthened the programme.⁵⁷

Palau (2018)

In Palau, W. bancrofi was transmitted by Culex mosquitoes. Over 20 000 people were at risk of infection. MDA was implemented from 2009 to 2012 using the DA regimen. Sustained surveillance, especially targeting migrants and robust support from development partners were key to the programme’s success.⁵⁸

Vietnam (2018)

In Vietnam, W. bancrofti, transmitted by Culex mosquitoes was identified as the predominant parasite for LF, placing nearly 700 000 people at risk. MDA was implemented from 2002 to 2008 using the DA regimen. The final MDA round achieved 86.3% coverage. In 2001, the baseline LF prevalence in endemic districts ranged from 0% to 3.6%. Strong community mobilisation efforts were integral to enhancing MDA coverage. LF control was integrated with the leprosy programme, which streamlined operations and data collection. The direct inspection protocol (DIP), focusing on 14 quality indicators, helped identify gaps in lymphoedema care. MMDP was further strengthened by empowering local health staff.⁵⁹

Wallis and Futuna (2018)

W. bancrofti, transmitted by Aedes mosquitoes, caused LF, posing an infection risk to over 15 000 people. MDA began in 2002 using the DA regimen that achieved 66% coverage. The success of the programme was attributed to a well-planned MDA strategy that targeted the entire territory, supported by widespread awareness campaigns. The small population size, limited mobility and strong collaboration with development organisations also played a key role.⁶⁰

Kiribati (2020)

In Kiribati, W. bancrofti was transmitted by Culex mosquitoes. MDA was implemented from 2001 to 2013 using the DA regimen, achieving 91% coverage. The success was driven by a robust community mobilisation and awareness campaigns that improved participation in MDA rounds. Collaborative efforts with international partners like Japan International Cooperation Agency (JICA) and Korea Centre for Disease Control and Prevention (KCDC) facilitated drug donations. A national morbidity register was established to systematically track LF cases, which supported MMDP services.⁶¹

Malawi (2020)

W. bancrofti was transmitted by Anopheles mosquitoes in Malawi, which posed a risk to approximately 13 million people. MDA was conducted from 2008 to 2013 using the DA. The final round of MDA achieved 83% coverage. The baseline mf prevalence in the country ranged from 0% to 9.1%. A key factor in the programme’s success was integrated disease control. LF control was integrated with the National Onchocerciasis Elimination Programme. Additionally, integrated surveillance for LF and dengue was established in co-endemic areas, with LF testing incorporated into routine activities. Individuals presenting with acute febrile illness at health facilities were tested for both LF and dengue in these regions. As LF and malaria share the same mosquito vectors (Anopheles funestus and Anopheles gambiae) in the country, periodic malaria control interventions further complemented the elimination efforts. The mHealth tool, MeasureSMS-Morbidity enabled real-time case detection and reporting of LF cases.⁶²

Yemen (2020)

In Yemen, W. bancrofti was transmitted by Culex mosquitoes, placing approximately 110 000 people at risk of infection. MDA was implemented from 2002 to 2011 using the IVM+ALB (ivermectine and albendazole) regimen that achieved 82% coverage. The baseline Ag prevalence ranged from 1.6% to 40.4%. Integration with the leprosy programme helped leverage healthcare infrastructure and manpower to improve programme reach. Vector control measures such as larvicidal spraying, IRS and bed nets as part of the malaria control complemented LF efforts. A strong PPP with the German Leprosy Relief Foundation facilitated drug procurement, health worker training and infrastructure development.⁶³

Bangladesh (2023)

In Bangladesh, the LF programme targeted W. bancrofti, transmitted by Culex mosquitoes, with over 70 million people at risk of LF infection. MDA was conducted from 2001 to 2015 using IVM+ALB, achieving 76.2% coverage in the final round. Baseline mf prevalence in endemic areas ranged from 0.2% to 16%. Key contributors to the programme’s success included strong community mobilisation, health system strengthening and the integration with the STH programme. MMDP was prioritised through training health workers and implementing a digital patient database for case tracking and care.⁶⁴

Lao People’s Democratic Republic (2023)

W. bancrofti, transmitted by Culex mosquitoes, was the causative agent for LF. Approximately 150 000 people were at risk of LF infection. MDA began in 2008 using the DA regimen, reaching 87% coverage in the final round. Baseline surveys in 2008 found Ag prevalence ranging from 1.9% to 27.4%. The programme benefitted from strong social mobilisation efforts, integrated surveillance for malaria, dengue and LF and strategic partnerships with international partners.⁶⁵

Brazil (2024)

In Brazil, W. bancrofti was the causative parasite, transmitted by Culex mosquitoes, placing around 1.5 million people at risk. Brazil relied exclusively on DEC for MDA between 2004 and 2016, focusing efforts in high transmission areas. The final MDA round achieved 69% coverage. The ‘Hope Clubs’ for MMDP supported patients and their families through training and peer engagement. Integration of LF interventions into Brazil’s broader health system, supported by specialised laboratory expertise, ensured accurate case detection and monitoring.^{66 67}

Timor-Leste (2024)

Timor-Leste eliminated LF, addressing both W. Bancrofti and B. Timori, which are transmitted by Anopheles mosquitoes. Approximately 1.1 million people were at risk of infection. MDA was implemented from 2005 to 2018 using the DA regimen and from 2019 onward with IDA. The programme achieved 76% coverage in its final round. Intensive community engagement was central to the programme’s success, supported by widespread mass media campaigns, which increased public awareness and participation. Essential care for patients with lymphoedema was prioritised, with health workers conducting regular home visits for monitoring the self-care.⁶⁸

Select best practices of the successful countries which India can adopt

As seen above, though the 21 countries largely followed WHO’s GPELF guidelines, they employed unique policies, strategies and tools befitting their sociocultural milieu. LF endemicity varied widely, with populations at risk ranging from just 1000 in the Marshall Islands to over 70 million in Bangladesh. The duration of MDA also differed, from as few as four rounds in Palau to as many as 18 rounds in Bangladesh, with coverage spanning from 65% to over 92% (figure 3). Vector ecology significantly influenced programmatic choices. Countries with Anopheles (Cambodia, Malawi, Togo, Sri Lanka) leveraged malaria tools like ITNs and IRS, and those with Culex focused on community mobilisation and health system strengthening. Island nations with Aedes vectors (eg, Cook Islands, Niue, Tonga) relied on localised surveillance and source reduction, aided by their smaller population. Despite these contextual differences, most successful programmes shared some common pillars, including high MDA coverage, strong community engagement, integration with other health programmes and international collaboration (figure 4). India’s LF programme already incorporates many of these approaches; however, a scrutiny and adoption of the best practices deployed by these countries can accelerate the pace of EPHP in India.

Figure 3. Historical overview of lymphatic filariasis elimination efforts in successful countries from 2015 to 2024. MDA, mass drug administration; PDR, People's Democratic Republic.

Figure 4. Adoption of various strategies by countries to achieve the elimination of LF as a public health problem. LF, lymphatic filariasis; MDA, mass drug administration.

Integrated disease management

India can benefit from an integrated disease management approach, as practiced in Egypt, Togo, Malawi, Vietnam, Yemen and Bangladesh. Currently, India’s LF programme is implemented vertically, with separate budgets and monitoring frameworks, leading to inefficiencies and overburdened frontline workers.⁶⁹ In India, such integration is both feasible and necessary due to the co-endemicity of multiple diseases like leprosy, STH, Visceral Leishmaniasis (VL), malaria and dengue, especially in high-burden states such as Uttar Pradesh (U.P.), Bihar, Jharkhand, Odisha and parts of the northeast.⁷⁰ The National Centre for Vector Borne Disease Control, which oversees programmes for control/elimination of LF, malaria, dengue and kala-azar under a single administrative umbrella, provides a strong institutional foundation for such convergence. In LF and malaria co-endemic areas, such as in parts of Odisha, U.P. and Bihar, integrated vector management strategies targeting multiple mosquito species could be implemented, even though in India, Culex is the only vector; tools like ITNs can reduce human vector contact. Since diseases like leprosy and LF share several programme components such as morbidity management (eg, lymphoedema, ulcers), integrating them could reduce operational redundancies. Training grassroots health workers to identify and manage both conditions could address early diagnosis and the shared social and psychological burdens. Albendazole, used in LF MDA, is already part of the biannual National Deworming Day targeting STH. Coordinating LF and STH interventions through school-based and community-based platforms could enhance coverage and reduce operational costs. However, synchronising intervention timelines remains a practical challenge. Addressing these differences requires robust microplanning at the district level to avoid operational mismatches. Integration also demands a coherent communication strategy as most programmes operate with disease-specific Information, Education and Communication (IEC) materials. The WHO NTD road map 2030 also strongly advocates for integrated approaches, including joint delivery of preventive chemotherapy, shared diagnostics platforms and coordinated monitoring strategies, aligned with broader health initiatives like Water, Sanitation and Hygiene (WASH) and vector control.⁷¹

Tailored drug distribution and community ownership

The elimination of LF in countries like Sri Lanka, Bangladesh, Egypt and Niue has been driven by context-specific drug distribution strategies, strong community engagement and sustained capacity building. India, with its vast population and diverse sociocultural landscape, can adapt these approaches to address gaps in MDA coverage. India currently follows a home-based drug distribution model, where community drug distributors visit households to administer drugs. While effective to some extent, this method faces challenges such as worker fatigue, absenteeism, refusals and limited flexibility to accommodate population mobility and festivals. India could diversify and tailor its delivery systems by adopting a flexible approach by combining house-to-house visits with school and religious institution-based distribution to improve reach and adaptability.

Social mobilisation is a proven driver of LF elimination, as seen in Sri Lanka’s COMBI programme and similar efforts in Vanuatu, Yemen and Egypt. India has a strong track record in this area within public health programmes, which can also be adapted for LF elimination. The Social Mobilisation Network, implemented for polio eradication, stands out as an exemplary model.⁷² This four-tiered system involved over 7000 frontline social mobilisers, primarily local women, who conducted house-to-house visits, organised children’s rallies and engaged local influencers to address vaccine hesitancy and refusal. Beyond polio, the network also boosted routine immunisation and maternal and child health services in marginalised communities. Similarly, during the COVID-19 vaccination campaign, India leveraged innovative approaches such as organising evening vaccination camps for agricultural workers and vaccination centres in religious spaces like Gurudwaras and traditional practices (eg, distributing peele chawal or yellow rice) to invite participation and build trust.⁷³ Comparable successes have been seen in expanding Long-lasting Insecticidal Nets (LLINs) coverage for malaria control. India can build on these experiences by adopting culturally tailored mobilisation strategies, flexible MDA scheduling and leveraging trusted community spaces for drug distribution.

Targeted treatment for migrant and never-treated populations

Migrants often miss MDA due to frequent relocations and lack of tracking systems, limiting their access to treatment. Since MDA is only conducted in endemic districts, migrants moving to non-endemic or post-MDA regions are not systematically covered, creating a gap in elimination efforts. There is no dedicated outreach for these mobile populations, raising the risk of reintroduction in areas where LF was previously under control. However, in India, obtaining accurate data on unorganised migrant labourers remains a significant challenge. The unorganised sector is vast and highly fragmented, with workers frequently moving between states or regions in search of employment. Many lack formal contracts or registration with government labour databases, making them invisible to official tracking systems. India could adopt Thailand’s model of mandatory LF testing for migrants, where health check posts at migration hubs like railway stations and state borders could screen them. The National Tuberculosis Elimination Programme in India uses active case finding and migrant mapping in high-risk populations like construction workers and slum dwellers. A similar mapping system could be adapted for LF, identifying migrant clusters for targeted outreach. The existing data platforms, such as eShram (a national database of unorganised workers), can be used to identify and reach migrant workers for MDA. In addition, guidelines should be formulated for mandatory LF testing in the onboarding process by employers in organised sectors. Collaborative efforts between health and labour departments and stronger migrant health policies are essential. Addressing the ‘never-treated’ population is also key, with active screening and treatment of missed populations, as used in Niue and Tonga, could be effective in India.

Strengthening morbidity management

While MMDP services are embedded in the national LF programme, several barriers continue to impede their effectiveness.^{38 39} Establishing dedicated LF care units, similar to Sri Lanka’s filarial clinics, could enhance care. Integrating LF care with other health programmes, as in Yemen’s combined LF and leprosy approach, can enhance treatment delivery. India's leprosy programme, which successfully provides post-exposure prophylaxis, regular disability monitoring, self-care training and footwear distribution through Primary Health Centres (PHCs), offers a replicable model for enhancing MMDP. Quality assessment frameworks like Vietnam’s DIP could improve MMDP services. Integrating digital tools like MeasureSMS-Morbidity could improve the real-time tracking of and reporting of cases. Brazil’s ‘Hope Clubs’, which provide a model for India to build similar community-based support systems for patients. Similar palliative care models have been successfully experimented in Kerala, which could inform strategies for managing advanced lymphoedema. Although a 6-week course of doxycycline has shown promising options for MMDP in some countries, an RCT conducted in India found no additional benefit when doxycycline was added to the essential package of care.⁷⁴ Finally, integrating regional medical colleges into LF care could enhance the capacity to address both clinical and social aspects of the disease.

Strengthening vector control

Malawi, Cambodia and Yemen used vector control strategies which contributed to the success. In Malawi, where Anopheles mosquitoes transmit both LF and malaria, the distribution of ITNs and IRS significantly reduced LF transmission. Similar approaches in Yemen, Cambodia, Lao PDR and Vanuatu, often under malaria programmes, yielded synergistic outcomes. Sri Lanka’s widespread use of bed nets played a key role in LF elimination. Indian experiences, especially evidence from Tamil Nadu and Pondicherry highlights the effectiveness of combining vector control measures, such as expanded polystyrene beads, larvivorous fish and chemical larviciding, with MDA.^{75 76} Notably, early efforts in 1992 showed that a 5-year programme in Pondicherry successfully reduced Culex quinquefasciatus density by 90% and mf prevalence by 60%.⁷⁷

Leveraging digital technology and data systems

India’s current LF elimination programme relies heavily on paper-based data collection, leading to delays and inefficiencies.⁷⁸ Digital tools, such as mobile apps and Global Positioning System (GPS)-enabled tracking systems, can improve data accuracy and real-time monitoring. Successful examples from Bangladesh and Malawi, where digital platforms streamlined case detection, reporting and treatment tracking, show how digital systems can enhance LF programme. India has already implemented digital platforms for other diseases like the Nikusth portal for leprosy, CoWIN for COVID-19 vaccination and Aarogya Sathi for tuberculosis (TB), but LF still relies on manual systems. The 2023 LF revised strategy emphasised the use of digital platforms for real-time programme monitoring.¹⁶

Conclusion

India has successfully eliminated guinea worm disease, polio, smallpox, trachoma and yaws, and is on track to eliminate TB, visceral leishmaniasis, malaria and LF. As the country approaches its target of eliminating LF by 2027, this is a critical juncture to review and possibly adopt the successful strategies of countries that have achieved elimination in the past decade. By learning from these experiences, India can identify best practices and refine strategies tailored to its unique sociocultural landscape and health infrastructure. A focused approach that emphasises integrated disease management, tailored drug administration, targeted efforts for migrants and never-treated populations, enhanced morbidity management, vector control response, robust community engagement and the strategic use of technology and partnerships will accelerate India’s journey toward LF elimination.

Data availability statement

All data relevant to the study are included in the article or uploaded as supplementary information.