Answer to Case 821

Answer to the Parasite Case of the Week 821: Giardia duodenalis cysts and trophozoites

Dr. Juhaina Bajaman noted that the trophozoites look like little ghosts floating around, and Idzi Potters commented on how they always have a nice smile 😊😂. The following image of a Giemsa-stained preparation from a duodenal aspirate is the best I've ever seen of a Giardia 'smile' - very nice, but nothing I ever want to have personally!

Several readers also commented on the use of AI to identify and classify intestinal protozoan parasites and asked for additional information. Therefore, I'm including it here for those who are interested (and I'll note that I make no money from this 😊): The system we use is the Techcyte Parasitology trichrome solution, part of the Fusion Parasitology suite. It's been a game changer for our laboratory, decreasing our screening time from 5 minutes to <30 seconds for negative specimens. Since we are in a low prevalence region for intestinal parasites, our positivity rate is <10%, so having a tool to quickly screen out negatives has greatly increased our testing capacity. The algorithm has also increased our sensitivity for detecting parasites. Importantly, it does not replace the need for skilled and highly trained technologists; our technologists use it as a tool to assist in the identification of parasites, but they are the ones that make the final call. All positive specimens are examined by traditional microscopy for confirmation. Our staff love the system - our staff satisfaction doubled after we implemented it. I'd be happy to speak to anyone off line if they would like more information! You can also view a webinar I gave on the topic a while back. Enjoy!