Poor biosecurity could lead to disease outbreaks in amphibian populations

Outbreaks of ranavirus and chytrid fungus have contributed to amphibian population declines. It has been suspected that biologists could contribute to pathogen outbreaks through poor biosecurity practices during sampling.... [ view full abstract ]

Outbreaks of ranavirus and chytrid fungus have contributed to amphibian population declines. It has been suspected that biologists could contribute to pathogen outbreaks through poor biosecurity practices during sampling. Biologists frequently co-house captured amphibians and do not change gloves between handling different individuals. We tested whether these poor biosecurity practices could facilitate transmission of ranavirus from infected to uninfected wood frog (Lithobates sylvaticus) tadpoles, and increase the likelihood of mortality. Co-housing tadpoles for only 15 minutes with 10% of individuals initially infected resulted in transmission and mortality of 50% of uninfected tadpoles. Not changing gloves between individuals when 10% were initially infected resulted in transmission of ranavirus and mortality of 70% of uninfected tadpoles. More extreme mortality was observed when tadpoles were co-housed for longer durations, or when the initial infection prevalence was >10%. Our results indicate that poor biosecurity practices can cause pathogen transmission between individuals, which could lead to disease outbreaks and decrease survival in populations. Biologists should change gloves or decontaminate them between handling individuals, and not co-house animals.