Evaluation of Mass Drug Administration through Transmission Assessment Survey in Udupi District of Karnataka, India

Annual Mass Drug Administration (MDA) of single dose of antifilarial drugs to all the eligible population was initiated in 2004 in Udupi district, a known endemic district for bancroftian filariasis. Nine rounds were implemented in this Implementation Unit (IU) with drug coverage ranging from 83% to 90% in different MDA rounds and with drug compliance rate of more than 65% in each of the MDA round. The baseline mf prevalence of 1.3% in 2004 was brought down to 0.09% in the year 2013. The impact assessment performed after 9 MDA rounds revealed <1% mf prevalence in each of the sentinel and spot check sites. The mf prevalence was further measured in 10 additional sites, which recorded <1% mf prevalence in all the sites. Having qualified for Transmission Assessment Survey (TAS), school-based survey was conducted in March 2014 in EUvaluation unit (EU) targeting 6 to 7-year children. The number of clusters, sample size, sampling fraction, critical cut off value, clusters and additional clusters to be sampled were estimated using Survey Sample Builder tool. A total of 1579 children from 53 clusters were screened against the target of 1553 and 5 were found positive for filaria antigen (0.3%) against the critical cut off value of 18 and hence the decision of stoppage of further rounds of MDA was taken. The “Post MDA Surveillance” was implemented in the EU, wherein the mf prevalence among 5-9-year age group in sentinel and spot check sites was measured annually for two years. The mf prevalence of such surveys was less than 1%. The second TAS conducted in 2016 after a gap of 2.4 years has shown presence of 0.6% filarial antigenemia thus passing the second TAS also.