From being one of the 9 States that contributed to 95% of the total burden of lymphatic filariasis in India some two to three decades ago, Tamil Nadu is now closer to achieving elimination of filariasis.
The doctors of the Directorate of Public Health (DPH) and Preventive Medicine and Institute of Community Medicine, Madras Medical College (MMC) — in an article “Tamil Nadu at the brink of eliminating lymphatic filariasis” — have pointed out that Tamil Nadu “stands as the only State in the country to successfully accomplish all requisite Mass Drug Administration (MDA) rounds and attain a microfilaria (Mf) rate of below one per cent”.
“By elimination, we mean that the disease has reached a threshold when it is no longer a public health issue. This is a big milestone. Lymphatic filariasis is a neglected tropical disease, and if not attended to properly, it can lead to lifelong disability. While reducing deaths due to filariasis is on one side, we should also reduce the stigma associated with the disease, as it has a huge impact on the person and the family,” said T. S. Selvavinayagam, Director of Public Health and Preventive Medicine. He, along with P. Vadivelan and D. Barani Kumar of the DPH, and Sudharshini Subramaniam of the Institute of Community Medicine, MMC, authored the article published in the Tamil Nadu Journal of Public Health and Medical Research.
Tamil Nadu, along with Andhra Pradesh, Bihar, Gujarat, Kerala, Maharashtra, Odisha, Uttar Pradesh and West Bengal had contributed to 95% of the total burden of filariasis in the country. According to the authors, Tamil Nadu was the pioneer State in the country to launch the MDA programme in Cuddalore district, during 1996, as a pilot project, even before the declaration by World Health Organisation Assembly for Elimination of Lymphatic Filariasis. Based on its success, the programme was extended to 25 other endemic districts in the State, from 1998.
“We needed to do things systematically. This was a long-drawn process, and we needed everyone’s contribution, including efforts from staff, public and local bodies that took measures for vector control,” Dr. Selvavinayagam added.
To begin with, the drug regimen that was adopted for MDA in Tamil Nadu was diethylcarbamazine citrate (DEC) six mg/kg of body weight. Since 2001, 400 mg albendazole was added. MDA was implemented in all 26 districts from 2007 to 2012, achieving a coverage of over 65% in all these rounds.
Transmission Assessment Surveys (TAS) carried out in 2014, 2016 and 2018 showed a Mf rate of 0.18%, 0.21% and 0.10% respectively. The MDA with DEC was stopped from 2015, but surveillance measures continued. One-time confirmatory mapping was done in all TAS confirmed blocks of previously endemic districts and in non-endemic districts. Among a total of 2,80,305 night blood samples collected in 45 health unit districts in 2022, three tested positive for Mf, the report said.
A testing and treating strategy was implemented among high-risk populations, such as migrants. The directorate carried out entomological data collection by identifying sentinel and random sites each year, while morbidity management and disability prevention strategies, including morbidity survey, line listing of patients with morbidity related to filariasis, promotion of hydrocele operation in camp approach and training of all patients from lymphoedema by doctors on limb oedema management, were done.
Tamil Nadu is now in the stage of the verification process for which the dossier is being prepared. The document will be submitted to the appropriate authority for certification of lymphatic filariasis elimination status, the authors said.
