Histopathology of infections by Learedius learedi Price, 1934 and Neospirorchis schistosomatoides Price, 1934 (Digenea: Spirorchiidae) in wild green turtles, Chelonia mydas L., from Bermuda

Vermetid gastropods as key intermediate hosts for a lineage of marine turtle blood flukes (Digenea: Spirorchiidae), with evidence of transmission at a turtle rookery

Blood flukes of the family Spirorchiidae Stunkard, 1921 are significant pathogens of marine turtles, both in the wild and in captivity. Despite causing considerable disease and mortality, little is known about the life cycles of marine species, with just four reports globally. No complete life cycle has been elucidated for any named species of marine spirorchiid, but the group is reported to use vermetid and fissurellid gastropods, and terebelliform polychaetes as intermediate hosts. Here we report molecular evidence that nine related spirorchiid species infect vermetid gastropods as first intermediate hosts from four localities along the coast of Queensland, Australia. ITS2 rDNA and cox1 mtDNA sequence data generated from vermetid infections provides the first definitive identifications for the intermediate hosts for the four species of Hapalotrema Looss, 1899 and Learedius learedi Price, 1934. Additionally, we provide a new locality report for larval stages of Amphiorchis sp., and evidence of three additional unidentified spirorchiid species in Australian waters. Based on the wealth of infections from vermetids during this study, we conclude that the previous preliminary report of a fissurellid limpet as the intermediate host for L. learedi was likely mistaken. The nine species found infecting vermetids during this study form a strongly supported clade exclusive of species of the other two marine spirorchiid genera for which sequence data are available; Carettacola Manter & Larson, 1950 which falls sister to the vermetid-infecting clade + a small clade of freshwater spirorchiids, and Neospirorchis Price, 1934 which is distantly related to the vermetid-infecting clade. We provide further evidence that spirorchiid transmission can occur in closed system aquaria and show that spirorchiid transmission occurs at both an important turtle rookery (Heron Island, southern Great Barrier Reef, Australia) and foraging ground (Moreton Bay, Australia). We discuss the implications of our findings for the epidemiology of the disease, control in captivity, and the evolution of vermetid exploitation by the Spirorchiidae.

Sleep in Parkinson's disease

Sleep disturbances are common in Parkinson's disease and comprise the entire spectrum of sleep disorders. On the one hand regulation of sleep and wakefulness is affected in Parkinson's disease, leading to the development of disorders, such as insomnia and daytime sleepiness. While on the other hand control of motor activity during sleep is impaired, with subsequent manifestation of parasomnias (mainly REM sleep behavior disorders, but also, albeit more rarely, sleepwalking, and overlap parasomnia). Restless legs syndrome has been reported to be frequent in patients with Parkinson's disease, although there is no consensus on whether it is more frequent in Parkinson's disease than in the general population. The same is true for sleep-related breathing disorders. Regarding the diagnosis of sleep disorders in patients with Parkinson's disease, one of the main challenges is correctly identifying excessive daytime sleepiness as there are many potential confounding factors, for example it is necessary to distinguish sleep-related breathing disorders from medication effects, and to distinguish restless legs syndrome from the concomitant presence of potential mimics specific to Parkinson's disease, such as akathisia, nocturnal leg cramps, nocturnal hypokinesia, early morning dystonia, etc. The correct diagnosis of REM sleep behavior disorder is also not always easy, and video-polysomnography should be performed in order to exclude mimic-like movements at the end of sleep apneas or violent periodic leg movements of sleep. These aspects and specific considerations about diagnosis and treatment of sleep disorders in patients with Parkinson's disease will be reviewed.

Spirorchiidiasis in marine turtles: the current state of knowledge

Blood flukes of the family Spirorchiidae are important disease agents in marine turtles. The family is near cosmopolitan in distribution. Twenty-nine marine species across 10 genera are currently recognized, but taxonomic problems remain and it is likely that more species will be discovered. Spirorchiids infect the circulatory system, where they and their eggs cause a range of inflammatory lesions. Infection is sometimes implicated in the death of the turtle. In some regions, prevalence in stranded turtles is close to 100%. Knowledge of life cycles, important for control and epidemiological studies, has proven elusive until recently, when the first intermediate host identifications were made. Recent molecular studies of eggs and adult worms indicate that a considerable level of intrageneric and intraspecific diversity exists. The characterization of this diversity is likely to be of importance in exploring parasite taxonomy and ecology, unravelling life cycles, identifying the differential pathogenicity of genotypes and species, and developing antemortem diagnostic tools, all of which are major priorities for future spirorchiid research. Diagnosis to date has been reliant on copromicroscopy or necropsy, which both have significant limitations. The current lack of reliable antemortem diagnostic options is a roadblock to determining the true prevalence and epidemiology of spirorchiidiasis and the development of effective treatment regimes.

Evidence of Diversity, Site, and Host Specificity of Sea Turtle Blood Flukes (Digenea: Schistosomatoidea: "Spirorchiidae"): A Molecular Prospecting Study

Neospirorchis (Digenea: "Spirorchiidae") are blood flukes of sea turtles. Trematodes tentatively identified as Neospirorchis sp. infect various sites within sea turtles inhabiting waters of the southeastern United States, but efforts to obtain specimens adequate for morphologic study has proven difficult. Two genetic targets, the internal transcribed spacer region of the ribosomal RNA gene and the partial mitochondrial cytochrome c oxidase subunit I gene, were used to investigate potential diversity among parasite specimens collected from stranded sea turtles. Sequence data were obtained from 215 trematode and egg specimens collected from 92 individual free-ranging cheloniid sea turtles comprising 4 host species. Molecular analysis yielded more than 20 different genotypes. We were able to assign 1 genotype to 1 of the 2 recognized species, Neospirorchis pricei Manter and Larson, 1950 . In many examples, genotypes exhibited host and site specificity. Our findings indicate considerable diversity of parasites resembling Neospirorchis with evidence of a number of uncharacterized blood flukes that require additional study.

Checklist of sea turtles endohelminth in Neotropical region

This paper presents a list of parasites described in sea turtles from the Neotropical region. Through the review of literature the occurrence of 79 taxa of helminthes parasites were observed, mostly consisting of the Phylum Platyhelminthes with 76 species distributed in 14 families and 2 families of the Phylum Nematoda within 3 species. Regarding the parasite records, the most studied host was the green turtle (Chelonia mydas) followed by the hawksbill turtle (Eretmochelys imbricata), olive ridley turtle (Lepidochelys olivacea), loggerhead turtle (Caretta caretta) and leatherback turtle (Dermochelys coriacea). Overall helminths were reported in 12 countries and in the Caribbean Sea region. This checklist is the largest compilation of data on helminths found in sea turtles in the Neotropical region.

Report ofNeospirorchis schistosomatoides Price 1934 (Digenea: Spirorchiidae) infecting a Green Turtle, Chelonia mydas Linnaeus, 1758 (Testudines, Cheloniidae), from Brazil

We report the occurrence of Neospirorchis schistosomatoidesPrice 1934 in a juvenile green turtle (Chelonia mydas L.1758) from the Brazilian coast. This species has been reported only in green turtles from the USA, Bermuda and Australia. Only two entire specimens and parts of six worms were found in the host’s heart. The collection, identification and morphometric data of intact specimens of N. schistosomatoides are rare and restricted to the original description. This paper presents the first report of N. schistosomatoides in green turtles from the western South Atlantic Ocean.

Spirorchiid Infection in Olive Ridley Turtle, Lepidochelys olivacea (Eschscholtz, 1829) (Testudines: Cheloniidae), from Brazil

The Olive Ridley turtle, Lepidochelys olivacea (Eschscholtz, 1829) (Testudines: Cheloniidae), is 1 of the 5 species of sea turtle found along the coast of Brazil. Little is known regarding infection by species of the family Spirorchiidae in the host, as only 1 report exists. This case report describes granulomas in different tissues associated to type 1 and 3 spirorchiid eggs in 5 L. olivacea from the Brazilian coast. The occurrence of the eggs was considered an incidental finding and may have contributed to the debility and death of the hosts. This is the second report of tissue lesions due to spirorchids eggs in this host and the first occurrence in Olive Ridley turtle from the Brazilian coast.

Fluke (Spirorchiidae) infections in sea turtles stranded on Taiwan: prevalence and pathology

The prevalence of spirorchiid fluke infections of marine turtles is high and may cause the death of the hosts throughout their ranges. Virtually nothing has been reported regarding the infective status of sea turtles stranded on Taiwan. Between 2007 and 2010, 30 green turtles (Chelonia mydas) and 2 loggerhead turtles ( Caretta caretta ), stranded and dead, were examined for spirorchiid flukes and their eggs. Twenty-four of the green turtles were juveniles, and the stranded loggerhead turtles were subadults. Adult spirorchiid flukes were found in 13 green turtles but not in the loggerheads. Four species of flukes were identified, namely, Leardius learedi , Hapalotrema postorchis , H. mehrai , and Carettacola hawaiiensis . The main infection sites were the major arteries and heart. Seventy percent of the green turtles harbored spirorchiid eggs, but no eggs were found in loggerheads. The largest eggs with bipolar spines, type I eggs, were found in every case. Although more than half of the stranded turtles were infected, parasite infections were not the main cause of death in the green turtles. Fishery by-catch is probably responsible for the mortality of these stranded turtles.

Spirorchiids (Digenea: Spirorchiidae) infecting a Hawksbill sea turtle Eretmochelys imbricata (Linnaeus 1758) from Brazil

The occurrence of Amphiorchis caborojoensis Fischthal & Acholonu 1976 and Carettacola stunkardi Martin & Bamberger 1952 in a young specimen of Hawksbill sea turtle Eretmochelys imbricata Linnaeus 1758 in Brazil was reported. Five A. caborojoensis trematodes were found in the small intestine (n=2) and liver (n=3), and two adult C. stunkardi specimens were collected from body wash. This is the first report of parasites of E. imbricata in Brazilian waters and Southwestern Atlantic Ocean and the second report of members of the Spirorchiidae family in that region. In addition, E. imbricata is a new host recorded for C. stunkardi.

Learedius learedi Infection in Black Turtles (Chelonia mydas agassizii), Baja California Sur, Mexico

Black turtle (Chelonia mydas agassizii) carcasses, recovered as a result of incidental capture in Magdalena Bay, Mexico, revealed invasion by spirorchiid trematode eggs in liver, kidney, intestines, muscle, heart, pancreas, and duodenum. Seventy-five adult Learedius learedi Price, 1934, were recovered from the heart of 1 turtle. Most of the organs showed a mild or absent inflammatory response in histological sections, with the exception of a pancreatic-duodenal section that revealed severe lymphocyte and phagocyte infiltration associated with an infestation of more than 200 eggs. A linear formation of 35 eggs from the pancreas toward the intestinal lumen is described as resembling migration. This is among the first reports of a parasitic infection of L. learedi Price 1934, in C. m. agassizii in Mexico.

Lesions caused by cardiovascular flukes (Digenea: Spirorchidae) in stranded green turtles (Chelonia mydas)

Evidence of infection with spirorchid flukes (Digenea: Spirorchidae) was sought at necropsy of 96 stranded green turtles, Chelonia mydas, that were examined during the course of a survey of marine turtle mortality in southeastern Queensland, Australia. Three species of spirorchid (Hapalotrema mehrai, H. postorchis, and Neospirorchis schistosomatoides) were identified. Severe disease due to spirorchid fluke infection (spirorchidiasis) was implicated as the principal cause of mortality in 10 turtles (10%), and appeared to be one of multiple severe problems in an additional 29 turtles (30%). Although flukes were observed in only 45% of stranded C. mydas in this study, presumed spirorchid fluke infection was diagnosed in an additional 53% of turtles, based principally on characteristic necropsy lesions and to a lesser extent on the histopathological detection of spirorchid eggs. Characteristic necropsy lesions included miliary spirorchid egg granulomas, which were observed most readily on serosal surfaces, particularly of the small intestine. Cardiovascular lesions included mural endocarditis, arteritis, and thrombosis, frequently accompanied by aneurysm formation. Resolution of thrombi was observed to occur via a combination of granuloma formation about indigestible components (spirorchid fluke egg shells) and exteriorization through the vessel wall, which resulted in granulomatous nodules on the adventitial surface. Septic aortic thrombosis complicated by disseminated bacterial infection, observed in five turtles, was recorded for the first time. Egg granulomas were ubiquitous in turtle tissues throughout this study. Although they generally appeared to be mild or incidental lesions, they were occasionally associated with severe multifocal granulomatous pneumonia or meningitis.

Efficacy of praziquantel in the treatment of green sea turtles with spontaneous infection of cardiovascular flukes

OBJECTIVE

To assess the efficacy of praziquantel as a treatment for cardiovascular flukes in turtles.

PROCEDURE

Six green sea turtles (Chelonia mydas) spontaneously infected with cardiovascular flukes (Digenea: Spirorchiidae) were treated orally with praziquantel, and necropsied 3 or 7 days later to look for flukes in the heart and major blood vessels. Six similar animals were maintained as untreated controls.

RESULTS

Absence of flukes in treated, but not control turtles, indicated that a one day course of treatment at a dose rate of 3 x 50 mg/kg body weight is effective.

CONCLUSION

This result should be of value for preventing disease in wild caught green turtles introduced into farms or aquaria.