Investigating the Potential Role of North American Animals as Hosts for Zika Virus

Abstract

The recent emergence of the mosquito‐borne Zika virus (ZIKV) in the Americas has become a global public health concern. While little is known about potential animal reservoirs for ZIKV, nonhuman primates are thought to play a role during enzootic transmission cycles. We describe a series of experimental infections designed to investigate whether species within certain taxonomic groups in North America have the potential to serve as ZIKV amplifying hosts or reservoirs. The objectives of this study were to (1) identify potential animal reservoirs in North America with an emphasis on wildlife and livestock, (2) examine ZIKV pathogenicity in neonatal and adult animals, and (3) evaluate the ability of animal models to recapitulate neonatal birth defects as seen in human patients. Species investigated include armadillos, cottontail rabbits, goats, mink, chickens, pigeons, ground hogs, deer mice, cattle, raccoons, ducks, Syrian Golden hamsters, garter snakes, leopard frogs, house sparrows, and pigs. Animals ranging in age from neonates to adults were inoculated with 105 PFU of one of two ZIKV strains (PRVA BC59 and FSS13025) by subcutaneous and intradermal injection. All animals were monitored daily for clinical signs of disease. Blood samples and body temperatures were collected on days 0–5, 7, 14, 21 and 28 post inoculation. Plaque assays, polymerase chain reaction (PCR), and plaque reduction neutralization tests were performed to detect viral presence and antibody production. Infectious virus was isolated from seven frogs and one armadillo. In addition, neutralizing antibodies were detected in goats, rabbits, ducks, frogs, and pigs. This study indicates that the animals tested to date are unlikely to act as animal reservoirs for ZIKV. However, goats, rabbits, frogs, and pigs could potentially serve as a sentinel species. Future work includes examining the role of amphibians in the transmission dynamics of ZIKV. Understanding the transmission cycle and maintenance of ZIKV in animals will help in developing effective surveillance programs and preventative measures for future outbreaks.Support or Funding InformationThis material is based upon work supported by Colorado State University Animal Models Core and the U.S. Department of Homeland Security under Grant Award Number DHS‐2010‐ST‐061‐AG0001. The views and conclusions contained in this document are those of the authors and should not be interpreted as necessarily representing the official policies, either expressed or implied, of the U.S. Department of Homeland Security.