Poor biosecurity could lead to disease outbreaks in animal populations

Abstract

Human-mediated disease outbreaks due to poor biosecurity practices when processing animals in wild populations have been suspected. We tested whether not changing nitrile gloves between processing wood frog (Lithobates sylvaticus) tadpoles and co-housing individuals increased pathogen transmission and subsequent diseased-induced mortality caused by the emerging pathogen, ranavirus. We found that not changing gloves between processing infected and uninfected tadpoles resulted in transmission of ranavirus and increased the risk of mortality of uninfected tadpoles by 30X. Co-housing tadpoles for only 15 minutes with 10% of individuals infected resulted in ranavirus transmission and 50% mortality of uninfected tadpoles. More extreme mortality was observed when the co-housing infection prevalence was >10%. Our results illustrate that human-induced disease outbreaks due to poor biosecurity practices are possible in wild animal populations.

Water sports could contribute to the translocation of ranaviruses

“…Gray et al . 23 recently provided evidence that ranavirus could adhere to examination gloves and hence contribute to transmission among amphibians that are processed as part of a pathogen surveillance study if gloves are not changed between animals. Ranaviruses can co-occur with other pathogens like Batrachochytrium spp 19,24–26 , which can also be translocated by human activities.…”

Frog Virology: Biosafety in an Experimental Farm

“…A herpesvirus-like dermatitis with numerous dorsal and lateral epidermal vesicle, was also detected in specimens of the spring frog, Rana dalmatina, in a north Italy region [24]. These enveloped viruses tend to be less stable in the environment, and transmission, from one enclosure to another by human vectors, is feasible but could be prevent by good hygiene practices [18].…”

“…Structural aspects should, then, be considered as the water supply (an effective transmission medium for ranaviruses) warm and frequently filtered; effective means of physical separation and facilities for people entry including access control; vehicle and vessel access [2,23,35]. Inadequate transportation prior to arrival at the facility, inappropriate housing and overcrowding are husbandry practices that facilitate infection diseases [18,32].…”

“…The infectious process involves genetics, environmental factors (pollution, temperature and other stressors) and inherent biological characteristics of the host (age, life stage, physiological aspects) that directly affect immune competence. Anthropogenic stressors also may facilitate emergence, compromising the imune system [2,18]. Additionally, subclinical infected hosts may serve as reservoirs for more susceptible amphibian species [18].…”

“…Anthropogenic stressors also may facilitate emergence, compromising the imune system [2,18]. Additionally, subclinical infected hosts may serve as reservoirs for more susceptible amphibian species [18].…”