The research team took advantage of genes that have multiple copies in the parasite genome to reveal parasites present at concentrations that are 10 times lower than the detection limit of current standard assays. Researchers compared three methods- light microscopy, the current standard molecular assay and the new assays, to detect malaria parasites in 498 samples randomly selected from a malaria survey in Tanzania.
Parasites were detected in 25 percent of samples by light microscopy, in 50 percent by the standard assay, and in 58 percent samples by the new assays. Compared to the new assays, the current molecular standard assay failed to identify 16 percent of malaria infections, and at least 40 percent of those contained parasite gametocytes, the parasite stage that is transmitted when mosquitoes bite an infected person.
The study is published in PLOS Medicine.