School based filaria transmission assessment survey at Purba Medinipur District, West Bengal; India in 2014.

Lymphatic filariasis is one of the neglected tropical diseases of world. India was set a target to eliminate lymphatic filarial within the year 2015 by administering Mass Drugs Administration (MDA) with diethyl carbamazine and albendazole for five consecutive years. MDA coverage was more than 80% - 92% of different MDA rounds in Purba Medinipur district. Impact of MDA programme was assessed by searching microfilaria through night blood survey. Prevalence of microfilaria was 2.4% to zero in all sentinel sites. Finally transmission assessment survey (TAS) as per WHO guidelines - 2011 of microfilaria was conducted on September and October’ 2014 among student of class I and II for making decision to stop or continue MDA. This district was sub-divided into three evaluation units (EUs), named Evaluation Unit-I, Evaluation Unit-II and Evaluation Unit-III to implement TAS programme. Sample Survey Builder (SSB) tool was used for sampling. Cluster survey was conducted with critical cut off value 20 in each EU. Immuno-chromatographic test (ICT) card was used to detect microfilaria among school students of class I and II (6 - 7 years age). All students of class-I and II of selected school were tested with ICT card, no sampling interval. Among the total enrolled school student of class-I and II, 3.67% were tested for microfilaria with ICT card. Among them, 51.3% were boys and 47.3% were girls. Out of total 5108 children surveyed only three (0.06%) was found positive for filarial antigen. All three cases had migratory history to filaria endemic areas and remain with relatives for >11 months. As proportion of positive cases did not cross the critical cut off value. So these three Evaluation Units were qualified to stop further MDA.