740m people are at risk in India from a neglected tropical disease

An estimated 740 million people across India are at risk of a disease that is largely neglected in the public discourse. Even if multiple cues are provided -- that it is a disease spread by mosquitoes or that the clinical symptoms of the disease appear 10 to 15 years after the initial infection or that it causes swelling and scarring of hands and legs of the affected person -- the chances are that most people would not be able to name it. The disease is Lymphatic Filariasis (LF), and it is endemic in around 339 districts across 20 states of India, and thus a public health challenge in the country.

LF causes disability in affected persons as a chronic disease through Lymphedema (tissue swelling) or swollen limbs (in both genders), elephantiasis (skin/tissue thickening) of the limbs or swelling of the scrotum (in men). It causes some form of disability and has a cost on health services’ utilisation. There are at least two reasons why LF does not get the attention it deserves. One, it mostly affects poor, vulnerable and voiceless people. Second, unlike other mosquito-borne diseases such as dengue or malaria, in which clinical symptoms appear soon after infection, the clinical symptoms of LF appear 10-15 years after exposure.

Fortunately, in the last two decades, there have been global and national efforts to bring down the burden of LF. In 2000, the World Health Organisation launched a global programme for elimination of LF by 2030. India has also committed to eliminate LF by 2027 -- three years ahead of the global timeline. Lymphatic Filariasis Elimination is one of the goals in India’s National Health Policy 2017.

In 2023, India adopted the “enhance” strategy for the elimination of lymphatic filariasis, which has five pillars of interventions. One of the key pillars is mission mode Mass Drug Administration (MDA). As part of MDA, the eligible population living in the endemic areas is administered a single either two drug regimens of Diethylcarbamazine (DEC) and albendazole or three drug regimens, which includes ivermectin -- once annually. These drugs are safe and essentially without major side effects. The MDA is the single most important and proven therapy that effectively interrupts the transmission of the disease. To the eligible population, the drugs need to be given once in a year; however, for administrative reasons of operational planning and availability of medicines, these activities are done twice in a year on fixed dates: February 10 and August 10. In an endemic area, MDA is done on either of the two dates only.

The other four pillars of the enhanced strategy are morbidity management and disability prevention; vector control; high level advocacy and innovative approaches.  These five pillars of interventions in the enhanced strategy are based upon solid foundation of evidence and learnings from experience of the past such as polio and measles elimination efforts in India.

India is in the last leg to eliminate LF. It is time to derive and use lessons from past public health programmes with a similar approach. The MDA for LF elimination is very similar to oral polio vaccine (OPV) administration under the polio elimination programme. The way OPV is needed to reach the target eligible children -- in every successive round of polio vaccination during national and sub-national immunisation days, the MDA needed to reach every eligible child and adult during national MDA rounds and high coverage should be achieved.

We have learnt from past elimination and control efforts for polio and measles and under HIV/AIDS control programmes that success of public health programmes requires both supply and demand side interventions. Both of us have been involved in polio elimination and measles control efforts in India. The learnings from the past indicate that the elected representatives at every level -- national, state and districts -- taking ownership of mass campaigns and the strong leadership of district magistrates/collectors to review the planning and daily evening meetings during the special drives -- ensure accountability, awareness and effective implementation. For last-mile community mobilisation, the panchayati raj institutions and their leaders, school and college teachers, and self-help groups are very important to raise awareness. The use of traditional communication modes such as loudspeaker announcements from local religious institutions can encourage people to avail the medicines provided by the health department. In large-scale community programmes, the field supervision of the campaign by national, state and district officers ensure improved functioning and implementation.

In LF elimination in India, on the supply side, there is high government commitment and sufficient financial allocation to implement the programme. It is time to raise awareness among people to come forward to take preventive medical interventions such as MDA and get treatment for the existing lymphedema and other related clinical conditions, all of which are provided free. Key stakeholders like professional associations of doctors and public health professionals and medical colleges need to be proactively engaged in this process.

The persistence of LF diseases in many districts of India reflects health inequity as the burden is disproportionately highest on the poor, underserved and marginalised communities and individuals. The upcoming MDA round in select states and districts is from August 10. Every citizen can contribute to ensure that India achieves the LF elimination target by learning about the disease, raising awareness about the MDA and taking the recommended medicine, if eligible. We all would like to see the day when LF is totally eliminated from India, and it should happen sooner than later. It is scientifically feasible.