Evaluation of a Novel Herpesvirus as a Sentinel for Population Health in Endangered Blanding’s Turtles (Emydoidea blandingii)
Abstract
While herpesvirus outbreaks have been associated with high morbidity and mortality in populations of captive Emydid chelonians worldwide, novel herpesviruses have also recently been identified in apparently healthy free-ranging Emydid populations.2-4,6,7,10 The clinical significance of this finding in the absence of an outbreak is currently unknown. The authors hypothesize that herpesvirus prevalence may be used as a sentinel of population health due to the virus’ propensity to recrudesce in times of stress or concurrent disease.1,5 Blanding’s turtles (Emydoidea blandingii), an endangered species in Illinois, have experienced range-wide declines because of habitat loss, degradation, and fragmentation.8,9 A novel herpesvirus, Emydoidea herpesvirus 1 (EBHV-1), was identified in Blanding’s turtles in DuPage County, Illinois in 2015. Subsequently, the investigators developed a highly sensitive and specific quantitative TaqMan PCR assay to target the DNA polymerase gene. Combined oral-cloacal swabs were collected from radiotelemetered and trapped Blanding’s turtles in DuPage (n=60 turtles) and Lake (n=81 turtles) County from May–September 2016. Radiotelemetered females had a significantly higher prevalence of EBHV-1 in May (24.4%) than June (3.7%), July (0%), August (0%), or September (7.7%) (p=0.001). This corresponds to the onset of nesting and may be associated with increased physiologic demands; however, all positive turtles were negative in subsequent months. Furthermore, there were no clinical signs associated with any turtle at the time they were detected with EBHV-1. This investigation is the critical first step to characterizing the implications of EBHV-1 on Blanding’s turtle population health and identifying management changes that may improve sustainability.
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