CHENNAI: The state government’s goal of achieving complete elimination of lymphatic filariasis (elephantiasis) before 2030 has become a challenge owing to imported cases by the migrant population.
According to the Directorate of Public Health and Preventive Medicine (DPH), the microfilarial rate in the state remains below 1%, but cases are being reported in migrant population apart from one or two indigenous cases. Microfilarial rate is the number positive cases among all those screened in a community.
Dr P Vadivelan, DPH officer on special duty, said, “People from lymphatic filariasis endemic states who migrate to Tamil Nadu import the cases. One or two positive cases of microfilaria is being reported. There are indigenous cases also, but the microfilarial rate in the state has not crossed one. We are working out strategies for regular screening of all migrant population,” said Dr Vadivelan.
Former Director of Public Health Dr K Kolandaswany said, “There is always threat of resurgence of cases in endemic districts because of migrant population. Also prevalence of culex mosquitoes which mostly transmit the parasite is a problem.” Culex mosquitoes breed in dirty and stagnant water. “In many villages, there still are open septic tanks or also in some places the effluents are released in the storm water drains and this poses risk,” he added.
To achieve elimination state, there should be zero cases in blood samples tested and in mosquitoes there should be zero carriers of microfilaria (immature larva). “After the State reported micro folarial rate less than 1% in endemic districts including Kancheepuram, Kanyakumari and Chennai, the Union Government told to stop mass drug administration (MDA) in endemic districts in 2013. From 2014, survey conducted in all districts taking blood smear showed the microfilaria rate less than 1%. The survey was conducted till 2022.
Last month, Union Health Minister Mansukh Mandaviya chaired the National Symposium on India’s Roadmap to Eliminate Lymphatic Filariasis, in which he said, “India is committed to eliminating Lymphatic Filaroasis by 2027, three years ahead of the global target.”