3 years ago

Repeated inoculations with the lung and heartworm nematode Angiostrongylus vasorum result in increasing larval excretion and worm burden in the red fox (Vulpes vulpes)

Repeated inoculations with the lung and heartworm nematode Angiostrongylus vasorum result in increasing larval excretion and worm burden in the red fox (Vulpes vulpes)
The French heartworm Angiostongylus vasorum is found in European red fox (Vulpes vulpes) and dog populations, where it appears to be spreading geographically. Once introduced into new areas, it establishes in local fox populations, typically to over 50% prevalence in a few years. High susceptibility and constant excretion of first stage larvae (L1) by the definitive hosts are prerequisites for sustaining high parasite biomass in a particular habitat. The present study explores the hypothesis that repeated ingestion of gastropods in nature will result in accumulation of adult worms and elevated excretion of L1 in feces. Experimentally infected foxes were subsequently inoculated via stomach tube once (9 weeks post initial inoculation) or twice (9 and 13 weeks post inoculation (wpi)) with 100 third stage A. vasorum larvae (L3) previously isolated from aquatic snails infected with L1 from a naturally infected dog. Despite large variation in fecal larval excretion for the individual animals within the groups, excretion of L1 was significantly higher in foxes twice inoculated as compared to foxes inoculated only once. With an outlier in the once inoculated group removed, excretion became significantly higher in the three times inoculated group. Establishment of adult worms varied and only a trend to higher worm burdens was found in the group of foxes inoculated three times. However, this became significant with the same single outlier removed. Overall, it appears that protective immunity to A. vasorum does not appear to occur in V. vulpes with animals exhibiting high infection intensities without obvious clinical signs. The increasing larval excretion in foxes being repeatedly exposed to A. vasorum L3 support the hypothesis that foxes under natural conditions may repeatedly ingest infected gastropods and remain a source of environmental contamination for several months, potentially contributing to the establishment of endemic foci through increasing L1 excretion.

Publisher URL: www.sciencedirect.com/science

DOI: S2213224416300451

You might also like
Discover & Discuss Important Research

Keeping up-to-date with research can feel impossible, with papers being published faster than you'll ever be able to read them. That's where Researcher comes in: we're simplifying discovery and making important discussions happen. With over 19,000 sources, including peer-reviewed journals, preprints, blogs, universities, podcasts and Live events across 10 research areas, you'll never miss what's important to you. It's like social media, but better. Oh, and we should mention - it's free.

  • Download from Google Play
  • Download from App Store
  • Download from AppInChina

Researcher displays publicly available abstracts and doesn’t host any full article content. If the content is open access, we will direct clicks from the abstracts to the publisher website and display the PDF copy on our platform. Clicks to view the full text will be directed to the publisher website, where only users with subscriptions or access through their institution are able to view the full article.