Determining Potential Vectors and Potential Hosts.

Jones and Woo provided us with some very useful information about the transfer of Trypanosoma catostomi. Delving deep into their work, one can discover a world of vector biology as well as host specificity and how closely related intermediate hosts may aid in the effect transfer of parasites upon a definitive host or lack thereof. Specifically, T. catostomi infects various species of fish in North America. Up until the work of Jones and Woo, it was unknown which species of fish play host to T. catostomi and which vectors are most effective in the transfer of this trypanosome.

            Jones and Woo cultured T. catostomi on a blood agar medium, and used their cultures to inoculate (mechanically introduce) potential definitive host species of fish, as well as potential vectors (leeches). The researchers determined that Actinobdella inequiannulata allowed metatrypanosomes to develop in their proboscis sheath. These metatrypanosomes (which were deemed to be T. catostomi) were infective to the white sucker fish (Catostomus commersoni) when the fish were both fed upon by A. inequiannulata and when the fish were inoculated with them. Two leeches which are vectors of other flagellate species were also observed to see if they would pose as effective vectors of T. catostomi however both potential vectors did now allow the complete development of the trypanosome which therefore inhibited the infection of white suckers when they were fed upon.

            Ultimately, this work determines that it is indeed helpful to look at the vector to determine what a particular host has been infected with. In the medical field, it may help to narrow down what a possible infection is by looking at exposure of potential vectors. It also poses the question of why certain parasites do not develop to completion within other species of the same genus of the intermediate host. Maybe the answers to this question can lead to eventual immunity of vaccinations to keep pesky parasites out of our bodies. And to think, the year 1992 wasn’t only known for my birthday!

Jones, Simon R. M., & Woo, Patrick T. K., 1992. Vector specificity of Trypanosoma catostomi and its infectivity to freshwater fishes. Journal of Parasitology. 78(1): 87-92.