Preliminary comparison of an in-house real-time PCR with the automated BD Max Enteric Parasite Panel for the detection of Giardia intestinalis

Giardia intestinalis is a parasite that commonly causes diarrheal disease throughout the world. An accurate and rapid diagnosis is essential to reduce the infection. Classically, diagnosis of giardiasis is performed by microscopic examination of stool samples, but in the recent years many DNA-based methods have been developed. In this preliminary observational study we compared the results of the commercial BD Max Enteric Parasite Panel (EPP) with an in-house real-time PCR for Giardia intestinalis. The study population was composed by 73 samples; of these, 27 resulted positive at both techniques and 39 negative. Seven samples were positive at the in-house real-time PCR and negative at the BD Max EPP. The Cohen's Kappa resulted 0.805 (95% CI 0.670-0.940). In conclusion, these preliminary results suggest that the Rt-PCR could possibly demonstrate higher sensitivity for the diagnosis of Giardia intestinalis than BD Max EPP, that tended to miss infection of low intensity.