RANAVIRUS EPIZOOTIC IN CAPTIVE EASTERN BOX TURTLES (TERRAPENE CAROLINA CAROLINA) WITH CONCURRENT HERPESVIRUS AND MYCOPLASMA INFECTION: MANAGEMENT AND MONITORING

Abstract

Frog virus 3 (FV3) and FV3-like viruses are members of the genus Ranavirus (family Iridoviridae) and are becoming recognized as significant pathogens of eastern box turtles (Terrapene carolina carolina) in North America. In July 2011, 5 turtles from a group of 27 in Maryland, USA, presented dead or lethargic with what was later diagnosed as fibrinonecrotic stomatitis and cloacitis. The presence of FV3-like virus and herpesvirus was detected by polymerase chain reaction (PCR) in the tested index cases. The remaining 22 animals were isolated, segregated by severity of clinical signs, and treated with nutritional support, fluid therapy, ambient temperature management, antibiotics, and antiviral therapy. Oral swabs were tested serially for FV3-like virus by quantitative real-time PCR (qPCR) and tested at day 0 for herpesvirus and Mycoplasma sp. by conventional PCR. With oral swabs, 77% of the 22 turtles were FV3-like virus positive; however, qPCR on tissues taken during necropsy revealed the true prevalence was 86%. FV3-like virus prevalence and the median number of viral copies being shed significantly declined during the outbreak. The prevalence of herpesvirus and Mycoplasma sp. by PCR of oral swabs at day 0 was 55% and 68%, respectively. The 58% survival rate was higher than previously reported in captive eastern box turtles for a ranavirus epizootic. All surviving turtles brumated normally and emerged the following year with no clinical signs during subsequent monitoring. The immediate initiation of treatment and intensive supportive care were considered the most important contributing factors to the successful outcome in this outbreak.

Peer Review #1 of "Ranaviruses and reptiles (v0.2)"

“…Descriptions of pathogenesis in reptiles infected with a variety of ranaviral strains in several host species under experimental, wild, and captive conditions are presented in Table 1. Despite differences in descriptions of pathogenesis and the fact the reports are often confounded with co-infections (Sim et al, 2016, Adamovicz et al, 2018, some common patterns of ranaviral pathology have emerged. General lethargy and inappetence are associated with many cases of ranaviral infection in reptiles; however, such clinical signs are common to many diseases and are not pathognomonic for ranaviral infection.…”

“…Reptilian hosts of ranaviruses experience a range of histological changes including necrosis and inflammation of the respiratory tract, pneumonia, conjunctivitis, stomatitis, esophagitis, tracheitis, necrosis of endothelial cells and the submucosa of the gastrointestinal tract, glomerulonephritis, multifocal hepatic necrosis, splenitis, intracytoplasmic inclusion bodies in many tissues, and necrotizing myositis (see Table 1). Evidence from epizootics in reptiles indicates that ranaviral infection can be accompanied by secondary pathogens that may exacerbate the disease and mask clinical signs of ranaviral infection (Stohr et al, 2013;Sim et al, 2016;Archer et al, 2017).…”

“…Although there are reports of ranaviral infection in traded reptiles (Hyatt et al, 2002;Stohr et al, 2013), no systematic survey of ranaviral infection in traded reptiles has been conducted. There have been some ranaviral disease outbreaks in private reptile collections and zoos (Marschang et al, 2005;Sim et al, 2016), but the full extent of disease prevalence is hard to assess, both because of inapparent infections, and lack of reporting of dead animals amongst reptile breeders and collectors. Ranaviral DNA sequences have been identified in mosquitoes associated with a ranavirus outbreak in box turtles, providing evidence for vector transmission (Kimble et al, 2014).…”

Population pharmacokinetics of enrofloxacin and its metabolite ciprofloxacin in clinically diseased or injured Eastern box turtles (Terrapene carolina carolina), yellow‐bellied sliders (Trachemys scripta scripta), and river cooters (Pseudemys concinna)

“…Infectious agents in wild and captive chelonians in North America include Mycoplasma , herpesvirus, ranavirus, and multiple co‐infections as significant causes of morbidity and mortality (Adamovicz et al, ; De Voe et al, ; Feldman et al, ; Kane et al, ; Sim et al, , ). There is a significant impact of vehicular trauma on both terrestrial and freshwater aquatic turtle populations, especially given the relatively higher risk of mortality for female turtles (Gibbs & Shriver, ; Steen et al, ).…”

Population pharmacokinetics of ceftazidime after a single intramuscular injection in wild turtles

“…Ceftazidime is used for management of traumatic injuries in turtles that may acquire secondary infections. The use in turtles has been documented by other veterinarians who treat infections in turtles (Allender et al., ; Gibbons & Steffes, ; Sim et al., ).…”