An inexpensive open source 3D-printed membrane feeder for human malaria transmission studies

Kathrin Witmer, Ellie Sherrard-Smith, Ursula Straschil, Mark Tunnicliff, Jake Baum, Michael Delves

The study of malaria transmission requires the experimental infection of mosquitoes with Plasmodium gametocytes. In the laboratory, this is achieved using artificial membrane feeding apparatus that simulate body temperature and skin of the host, and so permit mosquito feeding on reconstituted gametocyte-containing blood. Membrane feeders either use electric heating elements or complex glass chambers to warm the infected blood; both of which are expensive to purchase and can only be sourced from a handful of specialized companies. Presented and tested here is a membrane feeder that can be inexpensively printed using 3D-printing technology. Using the Plasmodium falciparum laboratory strain NF54, three independent standard membrane feeding assays (SMFAs) were performed comparing the 3D-printed feeder against a commercial glass feeder. Exflagellation rates did not differ between the two feeders. Furthermore, no statistically significant difference was found in the oocyst load nor oocyst intensity of Anopheles stephensi mosquitoes (mean oocyst range 1.3-6.2 per mosquito; infection prevalence range 41-79%). Open source provision of the design files of the 3D-printed feeder will facilitate a wider range of laboratories to perform SMFAs in laboratory and field settings, and enable them to freely customize the design to their own requirements.