Looking back to the strength of a people's movement against filariasis

The Hindu

22-04-2025

The World Health Organization has sought to eliminate filariasis, globally, by 2030, a decade later than its original target of 2020. While India's target year is now 2027, this deadline has been arrived at after several revisions: the National Health Policy had originally set the goalpost for 2015. Filariasis, clearly, has been difficult disease to eradicate.
While pioneering experiments by vector specialists over the years have helped India reduce its disease burden, consistent efforts are needed to eliminate the disease, reports have acknowledged.
'Filariasis is the common term for a group of diseases caused by parasitic nematodes belonging to the superfamily Filarioidea. Adult worms of these parasites live in the lymphatic system, cutaneous tissues or body cavity of the humans and are transmitted through vectors', explains a documents from the National Centre for Vector Borne Diseases Control.
Filariasis caused by nematodes that live in the human lymph system is called Lymphatic Filariasis (LF). The burden of lymphatic filariasis is massive in India, with as many as 670 million persons at risk for the disease, according to a report published in the Indian Journal of Medical Research in 2022.
While the disease has been around for decades in India, there still exist many misconceptions about it, says S. Sabesan, former director of the Indian Council of Medical Research -- Vector Control Research Centre, Puducherry.
Kerala's story with filariasis
Kerala was instrumental in spotlighting filariasis in India. In 1984-85, a group of filariasis affected persons in Alappuzha formed an association, and its president contested the general election that year, aiming to attract the attention of politicians and bureaucrats. It bore fruit. A Member of Parliament from Kerala S. Krishna Kumar, became the deputy minister in the Union Health Ministry. He called for action against filariasis in Kerala, which set the ball rolling, recalls Dr. Sabesan.
Kerala's culture of associations helped to further the project of eliminating filariasis, he says. All associations were amassed under the umbrella of the Filariasis control movement or 'Filco' movement. The project targeted removing floating vegetation where mosquitoes that cause the disease breed. The mosquitoes lay eggs on leaves and the larvae absorb oxygen from the air sacs in the roots of the plants. Understanding the breeding pattern of the mosquitoes helped remove the floating vegetation, which was then placed as manure in coconut groves.
To control mosquitoes the State Health Department also targeted Kerala's large resource of ponds and water bodies to develop aquaculture, using fish from dams. The fish would feed on the larvae, curtailing mosquito breeding.
Interdepartmental support
Support also came from Kerala's Agriculture Department which saw the potential of improving livelihoods in rural areas. Shramdhan workers cleaned temple tanks, canals and water bodies, and NABARD pitched in with financial support to remove the plants, and establish aquaculture.
In two years, inland fisheries had been developed. To add value to the removed water vegetation, hemp was cultivated. This improved the quality of fertilisers that coconut groves received. Ultimately, the Health Department roped in the Education Department to raise an army of schoolchildren who could spread awareness to help improve adherence to treatment of the disease.
The Health Department also used the knowledge of how village residents checked the feet of eligible young women to check if they harboured the disease before offering a marriage proposal. The Department made a young woman with lymphatic oedema, in whose family many women had been rejected owing to the disease, their mascot. The young woman recovered from filariasis after treatment and this boosted people's confidence. Her story was made into a short film, Yudham (war) and exhibited, giving further fillip to treating the disease. Alongside, the Department trained Filco workers to detect the disease and bring in patients for treatment.
Free clinics were opened to offer treatment. The next step was checking for hidden disease, which involved mass drug administration. Soon, the number of cases fell drastically indicating that the disease was in the elimination stage.
A win, and a mass strategy
The success of the experiment was shared at the WHO's meeting in 1996 in Kuala Lampur and the World Health Assembly decided on a strategy of administering a single dose of diethylcarbamazine citrate (DEC).
In India, the annual single dose mass therapy was introduced in 2002, but the nation-wide the scheme did not help in eliminating the disease, for want of follow-up care.
In 2006, the Union Health Ministry introduced the drug Albandazole that can have an effect on adult worms of the parasite. But there was a lack of compliance, even though the drugs were distributed. The Health Ministry found that despite distributing the drug there, was no reduction in the number of cases.
Meanwhile in Kerala another development took place.
The salt story
Through a project, salt-infused with a low dose of the drug DEC was introduced in Kerala. This project was launched with the support of the salt corporation in Thoothukudi in Tamil Nadu. Within a year, the number of filariasis cases fell significantly. The project's success was expanded in Tamil Nadu's Kanyakumari district in 2003.
By 2020, the Indian Council of Medical Research launched DEC salt in Andaman and Nicobar and successfully eliminated another variety of filariasis. This salt therapy could be used as an adjunct therapy across the country Dr. Sabesan has said in the white paper he has published on the subject: Not only is it odourless, but it also doesn't change the colour of food and is safe for pregnant women and children as well.
For the success to be sustained it is imperative that we achieve the target of elimination, he says. 'Tamil Nadu is doing well. But filariasis is found in Karnataka, Andhra Pradesh, Bihar and Uttar Pradesh as well. There are areas where filariasis is a challenge. If uncontrolled, filariasis will be reintroduced, as the vector is already present in the atmosphere. The low density carriers will build up gradually. So it is necessary to continue surveillance even after elimination is declared. Vector entomologists must focus on the mosquitoes and the vector,' he emphasises.