Lymphatic filariasis elimination: Update for mission possible.

In India, lymphatic filariasis is reported to be endemic in 250 districts (presently 256) in 16 states and 5 UTs. This disease is targeted for elimination, and to achieve this goal, the Government of India, in year 2004, launched the strategy of annual mass drug administration (MDA) with a single dose of diethylcarbamazine citrate (DEC) to the population living at risk of filariasis except for children below 2 years, pregnant women and seriously ill persons. The co-administration of DEC and albendazole was introduced for MDA in the country since 2007. The current strategy of the annual mass drug administration (MDA) is to reduce the microfilaria rate to below 1% so that the transmission is interrupted and the new generation will not get the infection. The affected people with this disease mainly known as elephantiasis will be provided home-based lymphoedema management procedure by simple washing and drying. The people affected with hydrocele will be motivated for surgical intervention. The programme has already listed more than 800,000 lymphoedema and 400,000 hydrocele cases. About 130,000 hydrocele cases have been operated.

The programme scaled up to reach about 600 million population achieving 100% geographical coverage in all 256 endemic districts. Coverage rates also improved from 73% in 2004 to 88% in 2015. The efforts to scale up MDA to reduce mf rate have shown promising results as 222 out of 256 endemic districts have reported microfilaria prevalence below 1% bringing them for validation through transmission assessment survey (TAS). Seventy-two districts have already cleared the first round of TAS.

It is estimated that the first round of TAS will be taken up in all endemic districts by the end of 2017. However, as per WHO guidelines, three rounds of TAS at intervals of 2–3 years have to be conducted to ensure elimination. Therefore, in spite of the achievement of microfilaria rate below 1% in all the 255 districts, the elimination process will start after 3–4 years. However, all efforts are to be made to achieve the target of reducing microfilaria rate to below 1% by the end of 2017.

The programme has also been evaluated by the Joint Monitoring Mission with national and international experts in few districts. The independent appraisal has also been done separately by ICMR which indicated in its report about strong commitment and leadership at national level for LF elimination. Adequate funds have been ensured so as to facilitate continuation of annual cycles of MDA implementation in all the endemic districts. Guidelines have been made available to the programme managers. The Directorate of NVBDCP receives adequate and timely scientific support from research organizations. A good rapport is maintained with the WHO Regional Office, and regular supply of albendazole and diagnostics is received from the donor. Technical support and additional financial requirements for capacity building and diagnostics are received from the WHO.

There are last mile challenges like survey of nonendemic districts for current status of LF endemicity, liquidating foci in nonendemic districts with treatment and vector control under integrated vector management as the whole district may not require MDA, sustaining the achievements gained so far and preventing failure in TAS, etc.