DAO 47:159-167 (2001)  -  doi:10.3354/dao047159

Survey of Florida green turtles for exposure to a disease-associated herpesvirus

Sadie S. Coberley1, Lawrence H. Herbst2, Llewellyn M. Ehrhart3, Dean A. Bagley3, Shigetomo Hirama3, Elliott R. Jacobson4, Paul A. Klein5,*

1Interdisciplinary Program in Biomedical Sciences, College of Medicine, University of Florida, Gainesville, Florida 32610, USA
2Department of Pathology, Albert Einstein College of Medicine, Bronx, New York 10461, USA
3Department of Biology, University of Central Florida, Orlando, Florida 32816, USA
4Department of Small Animal Clinical Sciences, College of Veterinary Medicine, University of Florida, Gainesville, Florida 32611, USA
5Department of Pathology, Immunology, and Laboratory Medicine, College of Medicine, Box 100275, University of Florida, Gainesville, Florida 32610, USA
*Corresponding author: E-mail:

ABSTRACT: A recently developed enzyme-linked immunosorbent assay (ELISA) was used to assess exposure of Florida wild green turtles Chelonia mydas to LETV, the herpesvirus associated with lung-eye-trachea disease (LETD). Plasma samples from 329 wild juvenile green turtles netted in the Indian River lagoon, along the Sebastian reef, or in the Trident basin (Indian River and Brevard Counties, Florida) were tested by ELISA for the presence of antibodies to LETV. Plasma samples from 180 wild juvenile green turtles were tested from these study sites to compare the prevalence of anti-LETV antibodies. While some plasma samples from each site contained anti-LETV antibodies (confirmed by Western blot analysis), plasma samples collected from the Indian River lagoon had statistically higher optical density values measured in the ELISA. No statistical differences were observed when these same plasma samples were analyzed for changes in the level of anti-LETV antibodies over 3 years (1997, 1998, and 1999). To explore the relationship between anti-LETV antibodies and fibropapillomatosis (FP), plasma from 133 green turtles scored for fibropapilloma tumor severity were tested by ELISA. There was no correlation between tumor severity and the presence of antibodies against LETV. Additional plasma samples collected from 16 tagged green turtles captured and sampled more than once (recaptures) were also tested to monitor antibody levels to LETV relative to the FP status of individual turtles over time. Again there was no clear relationship between FP tumor status and the presence of antibodies to LETV. Finally, ELISA tests on plasma from 13 nesting female turtles (9 green and 4 loggerhead) revealed high levels of anti-LETV antibodies in 11 individuals, including 2 loggerhead turtles. These results provide strong evidence that wild Florida green turtle populations at these 3 study sites are exposed to LETV or a closely related virus and that loggerhead turtles may be exposed as well. Based on a cutoff optical density value of 0.310, 71 out of the 329 wild Florida green turtles tested were seropositive for LETV antibodies (seroprevalence = 21.6%). In addition, no relationship between FP tumor severity or status and the presence of anti-LETV antibodies was found, further supporting the hypothesis that LETV and the FP-associated herpesvirus (FPHV) are separate infections of marine turtles.

KEY WORDS: Lung-eye-trachea disease · LETD · LETD-associated herpesvirus · LETV · Green turtle · Chelonia mydas · Chelonian herpesviruses · Antibodies · ELISA

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