Case of the Week 683

Answer to Case 683:Cryptosporidiumsp. oocystsThe following OUTSTANDING discussion is from our guest author, Hadel Go, a third year medical student with a strong interest in clinical parasitology._________________________________________We received some excellent feedback! Thank you all for leaving comments on the blog, on Twitter, and on LinkedIn.Yes, these areCryptosporidium oocysts. These protozoans can be identified by their size and consistent red color on modified acid-fast staining of stool samples. They can also be diagnosed from H&E stained tissue biopsies (see images here:Cryptosporidium, parasitewonders.com), but nucleic acid amplification tests (NAATs) andimmunofluorescence microscopy have the greatest sensitivity and specificity. The two main species that cause infection in humans areC. parvumandC. hominis, although several others are also capable. Species identification requires molecular methods like NAAT and/or sequencing.Transmission is fecal-oral through food and water contaminated by stool from an infected person or animal. Some examples include swallowing pool water, eating unwashed fruits/vegetables from unsafe farms where produce is contaminated with feces containing oocysts (@StephenTristam on Twitter noted a strong association with farming communities), handling infected farm animals especially calves (@KevKeel brought up infections among vet students!), caring for an infected person, engaging in anal sexual contact (as mentioned by @RA_MLS), and to...
Source: Creepy Dreadful Wonderful Parasites - Category: Parasitology Source Type: blogs