Assessing Onchocerca volvulus intensity of infection using mitochondrial sequence data
Skin snips were collected from people with epilepsy, incubated for 24 h in isotonic saline to allow emergence of microfilariae, and transferred to 80% ethanol. The ethanol solution containing the microfilariae was transferred into a 15ml falcon tube, filled to 15ml with MilliQ water, and centrifuged at 500g for 5min. Approximately 14 ml was aspirated carefully from the tube, leaving the microfilarial pellet in approximately 1 mL. This was transferred into a clean glass petri dish and each individual microfilaria was picked by aspiration using a pipette into 20 L lysis buffer. Whole genome amplification (WGA) was performed using the DOPlify kit (Perkin Elmer)according to the manufacturer's instructions 2 L lysate as the starting material. Sequencing libraries were constructed on samples whose DNA concentrations were above 1.0 ng/L using the Nextera DNA Flex/Illumina DNA prep library construction kits and barcoded using unique dual indexes, according to the manufacturers instructions (Illumina, San Diego, California, USA).