Document Type

Article

Publication Title

Pathogens

Abstract

A novel schistosome from Planorbella snails currently known as avian schistosomatid sp. C (ASC) was recently described as being capable of causing the papules associated with swimmer’s itch. We conducted a paired study with 24 human volunteers, exposing each of their forearms to five drops of water containing cercariae of ASC or Trichobilharzia stagnicolae, and examined the skin for papules 1–3 days later. A mixed effects model showed that only the parasite species significantly affected the number of papules, while prior experimental exposure, swimming history, and swimmer’s itch experience did not. The total number of papules produced by the two species were very different: ASC produced a total of 2 papules from the 298 cercariae used, compared to 49 papules from 160 T. stagnicolae cercariae, a difference factor of more than 43X, which was comparable to the odds ratio of 45.5 computed using the statistical model. A well-known agent of swimmer’s itch, T. stagnicolae, is able to penetrate human skin more frequently than ASC, likely meaning that ASC is only a minor cause of swimmer’s itch where T. stagnicolae is present. We also completed limited experiments that compared the cercarial behavior of the two species in vitro and in situ. A known stimulant of schistosome cercarial penetration, α-linolenic acid, did not stimulate ASC cercariae to initiate penetration-associated behaviors as frequently as T. stagnicolae. However, when placed on esophageal tissue of the known vertebrate host for ASC, Canada goose (Branta canadensis), ASC cercariae were observed penetrating the esophageal epithelium quickly, whereas T. stagnicolae cercariae did not exhibit any penetration behaviors.651

First Page

651

DOI

https://doi.org/10.3390/pathogens11060651

Publication Date

6-4-2022

Share

COinS
 
 

To view the content in your browser, please download Adobe Reader or, alternately,
you may Download the file to your hard drive.

NOTE: The latest versions of Adobe Reader do not support viewing PDF files within Firefox on Mac OS and if you are using a modern (Intel) Mac, there is no official plugin for viewing PDF files within the browser window.