Serological Association Between Spirorchidiasis, Herpesvirus Infection, and Fibropapillomatosis in Green Turtles From Florida

Abstract

Serodiagnostic tests for detecting green turtle (Chelonia mydas) antibody responses were developed to test the strength of association between exposure to spirorchid trematode antigens or herpesvirus antigens and having green turtle fibropapillomatosis (GTFP). Plasma samples from 46 captive-reared green turtles, including paired pre- and 1-yr post-inoculation samples from 12 turtles with experimentally induced GTFP, were found by enzyme-linked immunosorbent assay (ELISA) to be negative for antibodies to adult spirorchid (Learedius learedi) antigens. In contrast, all 12 turtles that developed experimentally induced GTFP converted within 1 yr from having negative to positive antibody reactivity to GTFP-associated herpesvirus antigens, whereas the three controls and four turtles that failed to develop tumors remained negative. Plasma samples from 104 free-ranging green turtles from two Florida (USA) coastal feeding grounds with different GTFP prevalences were tested by ELISA for antibodies to L. learedi adult antigens; and there was no statistically significiant association between antibody prevalence and sampling site. When a low optical density cutoff value (0.15) was used to interpret ELISA results, 98% of the turtles from each site were spirorchid antibody-positive and there was no association between antibody reactivity to spirorchids and GTFP status. When a higher negative cutoff value was used, however, a statistically significant association between antibody reactivity to spirorchids and GTFP-free status was found. These results suggest that spirorchids do not have a role in GTFP pathogenesis. All 20 of the tumor-bearing lagoon turtles had antibodies to herpesvirus antigens whereas only two (10%) of the tumor-free reef turtles had detectable anti-herpesvirus reactivity. The strong association between antibody reactivity to herpesvirus antigens and GTFP status in both captive-reared and free-ranging turtles is consistent with the hypothesis that the transmissible agent that causes GTFP is a herpesvirus.

Hematological profile of Chelonia mydas (Testudines, Cheloniidae) according to the severity of fibropapillomatosis or its absence

“…Data on fibropapillomatosis in sea turtles suggest a viral origin (Herbst et al 1998). However, demographic development, industrial and agronomic activities in sites located near beaches, bays and lakes may contribute for the increase in the incidence of the disease (Balazs 1991;Adnyana et al 1997).…”

Determinação de pesticidas organoclorados em tecidos de tartarugas-verdes (Chelonia mydas) provenientes da costa sudeste do Brasil: estudo da ocorrência em animais com e sem fibropapilomatose

“…As informações encontradas sugerem que a ocorrência de fibropapilomas em C. mydas pode ser de origem viral, pois várias famílias de vírus como Herpesviridae, Papoviridae, Poxviridae, Adenoviridae e Retroviridae são conhecidas por causarem lesões proliferativas e tumores (HERBST et al, 1998;ORÓS et al, 1998). A presença das sequências virais confirmada por PCR em tempo real, tanto em animais com lesões características da FP quanto na pele de animais aparentemente saudáveis , sugere que a progressão das lesões seja multifatorial e envolve potencialmente uma fase de promoção ou fase de desenvolvimento tumoral (QUACKENBUSH et al, 1998 (HERBST, 1994;HERBST;KLEIN, 1995;LANDSBERG et al, 1999;ARTHUR et al, 2008).…”

Diversity, impacts and diagnosis of pathogenic parasites in sea turtles from Queensland, Australia

“…Previous research has investigated the potential role of spirorchiids as causative agents of fibropapillomatosis (Aguirre et al, 1998;Dailey and Morris, 1995;Herbst et al, 1998;Work and Balazs, 2002).…”

“…Aguirre et al (1998) suggest that the diseases may often be concurrent due to immune suppression of the host, and that ova may accumulate in pre-existing tumours due to their highly vascularised nature. Herbst et al (1998) and Graczyk et al (1995) assessed plasma samples from sea turtles using enzyme linked immunosorbent assay (ELISA) and failed to find a consistent response to spirorchiid antigens in turtles with fibropapilloma. Subsequent evidence suggests an alphaherpesvirus as the primary causative agent (Herbst, 1994;Herbst et al, 1998;Quackenbush et al, 2001;Quackenbush et al, 1998).…”

“…Herbst et al (1998) and Graczyk et al (1995) assessed plasma samples from sea turtles using enzyme linked immunosorbent assay (ELISA) and failed to find a consistent response to spirorchiid antigens in turtles with fibropapilloma. Subsequent evidence suggests an alphaherpesvirus as the primary causative agent (Herbst, 1994;Herbst et al, 1998;Quackenbush et al, 2001;Quackenbush et al, 1998). It is suggested that although spirorchiids are unlikely to be the primary cause or the vector of the virus, they may have a role in the clinical progression of fibropapillomatosis (Herbst et al, 1998).…”