Authors

Discussion

>Purpose of research. Giardia duodenalis is a worldwide gastro-intestinal protozoan pathogen. Symptomatic giardiasis afflicts around 200 million people in Asia, Africa and Latin America with around 500,000 new cases per year. Sensitive and specific DNA-based identification in resource-limited settings may enhance diagnosis, which currently relies on microscopy or antigen test of stool. Here we apply isothermal recombinase-polymerase amplification (RPA) to identify Giardia by specific β-giardin DNA sequences in human faecal samples from an endemic setting, and in addition we perform intra-species assemblage typing.

Principal results. n≤ 238 of faecal samples collected from schools around Lake Albert, Uganda, were successfully DNA extracted. Results obtained to date reveal that n≤ 21/122 were positive by initial qPCR screening for the presence of Giardia DNA, and that n ≤ 20/79 were positive by RPA during the optimisation phase. In addition, n≤ 30 were typed by qPCR of the triose phosphate isomerase gene as assemblage A, n≤ 15 as Assemblage B, and n≤ 14 as mixed assemblage infection

Major conclusions. This is the first application of RPA to field samples from Uganda or Africa; with further refinement, it can be adapted to a point-of-care, rapid, sensitive and specific test for the diagnosis of Giardia in faecal samples. The Giardia assemblages identified from human faecal samples expand the knowledge of circulating assemblages in Uganda, and can be used as the basis for association studies of symptomatic giardiasis.