CHARACTERIZING THE EPIDEMIOLOGY OF HISTORIC AND NOVEL PATHOGENS IN BLANDING'S TURTLES (EMYDOIDEA BLANDINGII)

Comparison of Baseline Painted Turtle (Chrysemys picta) Health Assessments at a Confined Disposal Facility and a Protected Coastal Marsh in Southwestern Lake Erie, Ohio, USA

Dredging is commonly used to maintain navigational channels in freshwater lakes such as Lake Erie, and the dredged material may be discarded in confined disposal facilities (CDFs). The effects of these CDFs on wildlife health are largely unknown. We compared health assessments of painted turtles (Chrysemys picta) at two sites in southwestern Lake Erie, Ohio, USA in May 2022: CDF for dredged material (n=27), and a protected coastal marsh (PCM; n=24). Each turtle underwent a physical examination, blood collection for hematology and plasma biochemistry profiles, and testing for Chlamydia spp., herpesviruses, ranavirus (frog virus 3), and Mycoplasmopsis spp. via oral and cloacal swabs. Six turtles were positive for Chlamydia spp. (11.8%; 95% confidence interval [CI]: 4.4%-23.9%), two from the CDF and four from the PCM. One Chlamydia-positive turtle was co-infected with herpesvirus (2.0%; 95% CI: 0%-10.5%) with 96.3% homology with emydid herpesvirus. No ranavirus or Mycoplasmopsis species were detected (0%, 95% CI: 0%-6.7%). Turtles captured from the CDF had significantly higher heterophil percentages, heterophil/lymphocyte ratios, and glucose levels, but significantly lower total protein and calcium/phosphorus ratios than turtles from PCM. Turtles living in the CDF were hyperglycemic, potentially indicating increased stress levels compared to the normoglycemic turtles from PCM. As humans continue to alter wetland habitats, the impact of anthropogenic sites such as CDFs on freshwater chelonian health and welfare should be monitored.

Emydomyces testavorans Surveillance in Multiple Free-Ranging Terrestrial and Aquatic Chelonian Species in Illinois, USA

The order Onygenales contains multiple fungal pathogens that affect free-ranging and zoo-housed reptilian species. Emydomyces testavorans, an onygenalean fungus associated with skin and shell disease, has been sporadically detected in aquatic chelonians. Because of the recent discovery of this organism, little is known about its prevalence in free-ranging chelonians. The objective of this study was to perform surveillance for E. testavorans in six free-ranging aquatic and terrestrial chelonian species in Illinois, USA: Blanding's turtles (n=437; Emydoidea blandingii), painted turtles (n=199; Chrysemys picta), common snapping turtles (n=35; Chelydra serpentina), red-eared sliders (n=62; RES; Trachemys scripta elegans), eastern box turtles (n=73; Terrapene carolina carolina) and ornate box turtles (n=29; Terrapene ornata). Combined cloacal-oral swabs (COSs) or shell (carapace and plastron surfaces) swabs were collected from 2019 to 2021 and tested for E. testavorans using quantitative PCR. The PCR detected E. testavorans in COSs of an adult male, subadult female, and juvenile male Blanding's turtle (0.6%; 95% confidence interval [CI], 0.2-1.9%) and a shell swab from an adult female RES (1.6%; 95% CI, 0-8.7%). Shell lesions consistent with E. testavorans infection were present in two of the positive Blanding's turtles. These results document the rarity of this pathogen on the landscape in Illinois. Additional studies should determine this pathogen's impact on individuals and clarify its significance for conservation efforts of Blanding's turtle, in which E. testavorans has not been reported previously.

Hematology, Plasma Biochemistry, Protein Electrophoresis, and Pathogen Surveillance in Headstarted and Wild-Reared Populations of Blanding's Turtles (Emydoidea blandingii) in Three Northern Illinois, USA, Counties

Blanding's turtles (Emydoidea blandingii) are a species of conservation concern throughout their natural range. Headstarting is a common chelonian conservation technique in which neonates are reared in managed-care settings before release, but health assessments are rarely incorporated. From 2020 to 2021 we assessed headstarted turtle health pre-release and 1 mo, 1 yr, and 2 yr after release using physical examination, hematology, plasma biochemistry, protein electrophoresis, and pathogen detection in three Illinois counties. Results were compared to wild-reared juveniles in the same habitats. Overall, 767 assessments from 561 turtles were included. Wild-reared and 2 yr post-release headstarts had higher incidence of hemoparasites, asymmetrical nares, and increased creatine kinase and aspartate aminotransferase activities (P<0.05) compared to all other groups. Erythrocyte sedimentation rate and heterophil:lymphocyte ratio were greater, while total leukocyte and lymphocyte counts were lower (P<0.05) in pre-release headstarts compared to wild-reared juveniles. Total solids, albumin, and beta globulins were higher, while the calcium:phosphorous ratio was lower (P<0.05) in pre-release headstarts and wild-reared juveniles vs. other groups. Bile acid levels were highest in pre-release headstarts (P<0.05). Body condition and gamma globulins increased following release, while alpha globulins and the albumin:globulin ratio decreased following release (P<0.05). Two pre-release and one post-release headstart tested positive for Emydomyces testavorans, one post-release headstart was positive for Mycoplasmopsis sp., and nine post-release turtles were positive for adenoviruses. Overall, rearing conditions have a profound and temporally dynamic impact on Blanding's health assessment parameters. Future studies should evaluate long-term impacts on morbidity and mortality to support positive health status and conservation outcomes.

Herpesviruses in Captive Chelonians in Europe Between 2016 and 2020

Herpesviruses are important pathogens in tortoises and turtles, yet little is known about the epidemiology of these viruses. We analyzed herpesviruses detected by PCR in samples from captive chelonians in Europe according to virus strain, host species, year and season in which the animal was tested, and country in which the animal was kept. A total of 4,797 samples submitted to a diagnostic laboratory in Europe between January 2016 and December 2020 were evaluated. Of these, 312 (6.50%) were positive for herpesviruses. The types most commonly found were testudinid herpesvirus (TeHV)1 (143 positive, 45.83%) and TeHV3 (153 positive, 49.04%), but also included TeHV2 (1 positive, 0.32%), TeHV4 (3 positive, 0.96%), Terrapene herpesvirus 1 (7 positive, 2.24%), Trachemys herpesvirus 1 (2 positive, 0.64%), and three previously undescribed herpesviruses (0.96%). Herpesviruses were detected in chelonians in the families Testudinidae, Emydidae, Geoemydidae, and in the suborder Pleurodira. Among the species for which 100 samples or more were available, the highest proportions of positive samples (positivity rates) were found in samples from Horsfield's tortoises (Testudo horsfieldii) (14.96%), and radiated tortoises (Astrochelys radiata) (14.05%). Among tortoises (Testudinidae), viruses were most often detected in the spring, while in emydid turtles (Emydidae) they were most often detected in the summer. A comparison of the positivity rates according to country showed significant differences, with the highest rate in samples from Italy (16.01%). This study indicated possible differences in herpesvirus positivity rates depending on host species, virus strain, year of sampling, season, and country of origin. It provides useful information in further understanding fluctuations in infection rates as well as in helping to guide decision making for herpesvirus diagnostics in chelonian patients. It also provides evidence for the international dispersal of herpesviruses with their hosts through international trade.