Fig. 1

Reduction of host DNA by restriction enzyme digestion enhances PCR amplification of parasite DNA. DNA extraction from parasite-infected whole blood yields a DNA sample containing high amounts of host DNA (blue) and low amounts of parasite DNA (bright red). a Performing conventional PCR on this sample, using universal primers, amplifies primarily host DNA (blue), and yields sequencing reads almost entirely belonging to the host. b In contrast, restriction enzyme digestion of host DNA prior to PCR alters the ratio of host to parasite DNA in the initial sample, allowing for selective amplification of parasite DNA (bright red) and resulting in an increase in the relative number of parasite amplicons post-PCR and an increase in the sensitivity of parasite detection via NGS