First case of ranavirus and associated morbidity and mortality in an eastern mud turtle Kinosternon subrubrum in South Carolina

Abstract

Ranaviruses are double-stranded DNA viruses that infect amphibians, fish, and reptiles, causing global epidemics in some amphibian populations. It is important to identify new species that may be susceptible to the disease, particularly if they reside in the same habitat as other at-risk species. On the Savannah River Site (SRS) in Aiken, South Carolina, USA, ranaviruses are present in several amphibian populations, but information is lacking on the presence, prevalence, and morbidity of the virus in reptile species. An eastern mud turtle Kinosternon subrubrum captured on the SRS in April 2014 exhibited clinical signs of a ranaviral infection, including oral plaque and conjunctivitis. Quantitative PCR analyses of DNA from liver tissue, ocular, oral, nasal, and cloacal swabs were all positive for ranavirus, and sequencing of the template confirmed infection with a FV3-like ranavirus. Histopathologic examination of postmortem tissue samples revealed ulceration of the oral and tracheal mucosa, intracytoplasmic epithelial inclusions in the oral mucosa and tongue sections, individualized and clusters of melanomacrophages in the liver, and bacterial rods located in the liver, kidney, heart, stomach, and small intestine. This is the first report of morbidity and mortality of a mud turtle with a systemic ranaviral infection.

Ranavirus in an outbreak of dermatophilosis in captive inland bearded dragons (Pogona vitticeps)

“…Ranavirus infections in amphibians and chelonians are systemic and often fatal, and virus is most highly concentrated in the kidney, spleen and liver . In European amphibians, chronic ranaviral disease has been characterized by skin ulceration without gross internal lesions .…”

Molecular Confirmation of Ranavirus Infection in Amphibians From Chad, Africa

“…This finding highlights the importance of wildlife health and disease monitoring, even when a positive result may be unexpected. Ranaviruses have been associated with disease in other species of aquatic turtles from Asia, Europe and North America (37)(38)(39)(40) but there is also evidence that some species of aquatic turtles can have asymptomatic ranavirus infections (41,42). As we detected only a single positive animal, and sampled only two, additional understanding of Chadian turtle populations and surveillance for ranavirus may elucidate what impact, if any, they have on these animals and animal populations.…”

Trace Amounts of Ranavirus Detected in Common Musk Turtles (Sternotherus odoratus) at a Site Where the Pathogen Was Previously Common

“…In Australia, BIV (Bohle iridovirus isolate; FV3 species) has been detected in wild turtles in northern Queensland [ 22 ] and used in challenge experiments to demonstrate pathogenicity in chelonians and influence of temperature and exposure time [ 23 , 24 ]. In North America, FV3 and FV3-like ranaviruses have been reported in the wild in one Gopher Tortoise in Florida ( Gopherus polyphemus ) [ 25 ], one Eastern Mud Turtle ( Kinosternon subrubrum ) in South Carolina [ 26 ], one Common Snapping Turtle in southern Ontario ( Chelydra serpentina ) [ 20 ], Eastern Painted Turtles in Virginia ( Chrysemys picta picta ) [ 27 ], a Florida box turtle ( Terrapene carolina bauri ) in Florida [ 25 ], and Eastern Box Turtles in Georgia, Pennsylvania, New York, North Carolina, Tennessee, Texas, and Virginia ( Terrapene carolina carolina ) [ 25 , 28 , 29 , 30 ]. In T. c. carolina , outbreaks have led to population declines of 28–71% over 2–3 years (reviewed in [ 17 ]); however, we know little about the population-level dynamics of ranavirus in other turtles due to a lack of regular monitoring or only single individuals presenting symptoms that result in testing for ranavirus.…”