Antigenic evidence of lymphatic filariasis transmission in infection persistent endemic districts of Central Nepal during post mass drug administration

BackgroundIn Nepal, out of 75, 61 districts were endemic with lymphatic filariasis (LF) and completed 6 to 11 rounds of mass drug administration (MDA) with diethylcarbamazine (DEC) and albendazole from 2007 to 2017 in almost all endemic districts of Central Nepal with the aim of eliminating lymphatic filariasis by 2020 but due to fail in transmission assessment Survey (TAS) in some Terai districts of Nepal, aim of elimination was extended to 2030. Antigenemia prevalence have been consistently <2% in all sentinel and check spot sites since 2017 and transmission assessment survey passed in 2018 but in some foci there was low level persistent of infection of W. bancrofti was seen in 4 endemic districts of central Nepal so present study has been carried out with the aim of assessing antigenic prevalence in children borne after MDA program to understand evidence of new infection of LF in selected districts Methodology and principal findingsAntigenemia survey was carried out in communities children whose borne after MDA program from selected districts of central Nepal. Two study districts had significantly improved infection to the prior study but two other districts had drastic change. Few hydrocele cases were found but no any children found antigen positive with hydrocele cases. ConclusionsThese results indicates that W. bancrofti transmission was near to break point in one hilly district (Lalitpur) and one Terai district (Bara) while other two districts from Terai (Mahottari) and hills (Dhading) may requires further intervention. Targeted testing and treatment along with comparative study of children with adult should be required similarly number of MDA rounds should be increased. Author summaryLymphatic filariasis is neglected tropical disease which cause the disability to human beings which is caused by filarial nematode and transmitted by mosquitoes. Nepal government was completed 6-11 rounds of antifilarial medicine with DEC and albendazole between 2007 to 2017 in all endemic districts of central Nepal. TAS report showed low level of infection in all study sites. The present study reports assessed antigenic prevalence of 4 infection persistent endemic districts of central Nepal with high signals than prior study in 2 areas while other 2 areas showed in elimination phase so further investigation along with number of MDA rounds should be required to interrupt transmission in high antigenic prevalence districts. Our results suggest that further xenomonitoring and microfilaremia study should be required for informed decision, targeted test and treatment should required.