Answer to Case 593

Answer to Parasite Case of the Week 593: Strongyloides fuelleborni

This fascinating zoonotic parasite is endemic to parts of sub-Saharan Africa and infects both human and non-human primates. It is likely under-reported, which may be due to the resemblance of its eggs to those of the hookworms. Unlike hookworm eggs which are shed in an unembryonated state, the eggs of S. fuelleborni typically contain fully-developed larvae.

Similar appearing eggs with larvae may also be seen with heavy infections with Strongyloides stercoralis; however, the eggs are seen in conjunction with larvae, and occasionally adult worms, which are not seen with S. fuelleborni cases. Here are a couple of past examples of S. stercoralis from my blog with adults, larvae and eggs:
Case 469 Question and Answer
Case 499

Idzi Potters and his colleagues suspected S. fuelleborni in this case based on the appearance of the eggs, and were later able to confirm the identity through sequencing of the 18S rRNA gene.

After leaving the specimen in the refrigerator for 5 days, Idzi was also able to observe larvae from the parasite including the following example:

You can read the whole report in his recent publication: https://doi.org/10.1016/j.clinpr.2020.100031

Thanks again to Idzi and the Institute of Tropical Medicine Antwerp for donating this case!