Initial pen and field assessment of baits to use in oral rabies vaccination of Formosan ferret-badgers in response to the re-emergence of rabies in Taiwan

PLoS One. 2018 Jan 2;13(1):e0189998. doi: 10.1371/journal.pone.0189998. eCollection 2018.

Abstract

Background: Taiwan had been considered rabies free since 1961, until a newly established wildlife disease surveillance program identified rabies virus transmission within the Formosan ferret-badger (Melogale moschata subaurantiaca) in 2013. Ferret-badgers occur throughout southern China and Southeast Asia, but their ecological niche is not well described.

Methodology/principle findings: As an initial feasibility assessment for potential rabies control measures, field camera trapping and pen assessment of 6 oral rabies vaccine (ORV) baits were conducted in Taiwan in 2013. 46 camera nights were recorded; 6 Formosan ferret-badgers and 14 non-target mammals were sighted. No baits were consumed by ferret-badgers and 8 were consumed by non-target mammals. Penned ferret-badgers ingested 5 of the 18 offered baits. When pen and field trials were combined, and analyzed for palatability, ferret-badgers consumed 1 of 9 marshmallow baits (11.1%), 1 of 21 fishmeal baits (4.8%), 0 of 3 liver baits, and 3 of 3 fruit-flavored baits. It took an average of 261 minutes before ferret-badgers made oral contact with the non-fruit flavored baits, and 34 minutes for first contact with the fruit-based bait. Overall, ferret-badgers sought out the fruit baits 8 times faster, spent a greater proportion of time eating fruit baits, and were 7.5 times more likely to have ruptured the vaccine container of the fruit-based bait.

Conclusions/significance: Ferret-badgers are now recognized as rabies reservoir species in China and Taiwan, through two independent 'dog to ferret-badger' host-shift events. Species of ferret-badgers can be found throughout Indochina, where they may be an unrecognized rabies reservoir. Findings from this initial study underscore the need for further captive and field investigations of fruit-based attractants or baits developed for small meso-carnivores. Non-target mammals' competition for baits, ants, bait design, and dense tropical landscape represent potential challenges to effective ORV programs that will need to be considered in future studies.

MeSH terms

  • Animals
  • Carnivora
  • Ferrets
  • Food*
  • Rabies / epidemiology
  • Rabies / prevention & control*
  • Rabies Vaccines / administration & dosage*
  • Rabies Vaccines / immunology
  • Taiwan / epidemiology

Substances

  • Rabies Vaccines

Grants and funding

The authors received no specific funding for this work.