Molecular xenomonitoring as a post-MDA surveillance tool for global programme to eliminate lymphatic filariasis: Field validation in an evaluation unit in India

This study validates a standard protocol for molecular xenomonitoring of infection in vectors (MX) at an EU as a complem entary tool for TAS to stop MDA and its utility for post-MDA or post-validation surveillance. MethodologyThe study was conducted in Cuddalore district, Tamil Nadu, India, which was found eligible for TAS after 15 annual rounds of MDA (4 with DEC alone and 11 with DEC plus albendazole). The district was divided into two EUs as per the TAS protocol and one EU was randomly selected for the study. A two-stage cluster design vector sampling, developed and validated at a sub-district level, was implemented in 30 randomly selected clusters in the EU. FemaleCulex quinquefasciatus were collected placing gravid traps overnight (1800 –0600 hrs) inside the premises of systematically selected households. Pools of 20–25 blood-fed, semi-gravid and gravidCx.quinquefasciatus were subjected to real-time quantitative PCR (polymerase chain reaction) assay for detectingWuchereria bancrofti DNA. Pool infection rate (% of pools positive forW.bancrofti DNA), and the estimated prevalence ofW.bancrofti DNA in mosquitoes and its 95% confidence interval were calculated. Additionally, in these 30 clusters, microfilaria (Mf) survey among individuals>5 years old was carried out. School-based TAS was conducted using Immunochromatographic Card Test (ICT) in the EU. Prepared itemized cost-menu for different cost components of MX survey and TAS were estimated and compared. ResultsMX surv...
Source: PLoS Neglected Tropical Diseases - Category: Tropical Medicine Authors: Source Type: research