Ecological Routes of Avian Influenza Virus Transmission to a Common Mesopredator: An Experimental Evaluation of Alternatives

Authors

J. Jeffrey Root, USDA/APHIS/WS National Wildlife Research CenterFollow
Kevin T. Bentler, United States Department of AgricultureFollow
Susan A. Shriner, USDA/APHIS/WS National Wildlife Research CenterFollow
Nicole L. Mooers, United States Department of Agriculture
Kaci K. VanDalen, USDA/APHIS/WS National Wildlife Research CenterFollow
Heather J. Sullivan, USDA/APHIS/WS National Wildlife Research CenterFollow
Alan B. Franklin, United States Department of AgricultureFollow

Document Type

Article

Date of this Version

2014

Citation

Root JJ, Bentler KT, Shriner SA, Mooers NL, VanDalen KK, et al. (2014) Ecological Routes of Avian Influenza Virus Transmission to a Common Mesopredator: An Experimental Evaluation of Alternatives. PLoS ONE 9(8): e102964. doi:10.1371/journal.pone.0102964

Comments

U.S. government work.

Abstract

Background: Wild raccoons have been shown to be naturally exposed to avian influenza viruses (AIV). However, the mechanisms associated with these natural exposures are not well-understood.

Methodology/Principal Findings: We experimentally tested three alternative routes (water, eggs, and scavenged waterfowl carcasses) of AIV transmission that may explain how raccoons in the wild are exposed to AIV. Raccoons were exposed to 1) water and 2) eggs spiked with an AIV (H4N6), as well as 3) mallard carcasses experimentally inoculated with the same virus. Three of four raccoons exposed to the high dose water treatment yielded apparent nasal shedding of >10^2.0 PCR EID₅₀ equivalent/mL. Little to no shedding was observed from the fecal route. The only animals yielding evidence of serologic activity during the study period were three animals associated with the high dose water treatment.

Conclusions/Significance: Overall, our results indicate that virus-laden water could provide a natural exposure route of AIV for raccoons and possibly other mammals associated with aquatic environments. However, this association appears to be related to AIV concentration in the water, which would constitute an infective dose. In addition, strong evidence of infection was only detected in three of four animals exposed to a high dose (e.g., 10^5.0 EID₅₀/mL) of AIV in water. As such, water-borne transmission to raccoons may require repeated exposures to water with high concentrations of virus.