RESUMEN
The St. Lawrence Estuary (SLE) beluga Delphinapterus leucas in Quebec, Canada, is endangered due to intensive hunting in the 19th and 20th centuries and subsequent anthropogenic contamination and human activities in the region. Infectious disease is a primary cause of death in this population. The protozoan parasite Toxoplasma gondii is reported in numerous marine mammal species, including beluga. In the present study, 55 tissue samples (heart and brain) collected from 34 stranded SLE beluga were analysed by PCR followed by DNA sequencing and restriction fragment length polymorphism analysis (RFLP) to determine the PCR prevalence and genotypes of T. gondii in these beluga. Of 34 beluga tested, 44% were positive for T. gondii by PCR, with males having a higher prevalence of infection than females and with more infected neonates and juveniles than adults. Molecular analyses indicated that all T. gondii infecting stranded SLE beluga grouped into genotype II, which predominates in humans. While our results indicate that a high prevalence of stranded beluga are PCR-positive for T. gondii infection, very few deaths are attributed to toxoplasmosis based on published necropsy results. Toxoplasma gondii can cause a range of diseases, including neurological deficits, and more data are needed to investigate this parasite's effect on population recovery.
Asunto(s)
Ballena Beluga , Estuarios , Toxoplasma , Toxoplasmosis Animal , Animales , Ballena Beluga/parasitología , Canadá , Femenino , Gelatina , Genotipo , Masculino , Polimorfismo de Longitud del Fragmento de Restricción , Quebec , Toxoplasma/aislamiento & purificaciónAsunto(s)
Animales Salvajes , Ballena Beluga/parasitología , Borrelia burgdorferi/aislamiento & purificación , Erysipelothrix/aislamiento & purificación , Calentamiento Global/estadística & datos numéricos , Toxoplasma/aislamiento & purificación , Zoonosis/epidemiología , Animales , Animales Salvajes/microbiología , Animales Salvajes/parasitología , Animales Salvajes/virología , Regiones Árticas/epidemiología , Canadá/epidemiología , Dieta , Encefalitis Transmitida por Garrapatas/epidemiología , Encefalitis Transmitida por Garrapatas/virología , Humanos , Cubierta de Hielo , Incidencia , Indígenas Norteamericanos , Enfermedad de Lyme/epidemiología , Enfermedad de Lyme/microbiología , Salud Pública/métodos , Salud Pública/tendencias , Siberia/epidemiología , Toxoplasma/genética , Toxoplasmosis/epidemiología , Toxoplasmosis/parasitología , Toxoplasmosis/prevención & control , Incertidumbre , Zoonosis/parasitología , Zoonosis/prevención & control , Zoonosis/transmisiónRESUMEN
Human anisakidosis is a recognized Arctic zoonosis that is directly related to the consumption of traditional Inuit foods, particularly raw fish. The epidemiology of infections with the zoonotic anisakid nematodes Anisakis simplex and Pseudoterranova decipiens was investigated from August 2007 to July 2009 in Inuit-harvested fish and marine mammals from Inuit regions of Nunavik, Nunavut, and Nunatsiavut, Canada. Fish were tested for anisakid larvae using the pepsin-HCl digestion method, and the stomachs or stomach contents of beluga whales, walruses, and three seal species were examined for anisakids. Anisakids were found in seven of eight fish species, as well as in ringed seals (18.2%; 31/170), bearded seals (75.0%; 12/16), and beluga whales (78.9%; 15/19), but not walruses (0%; 0/15). In fish, the odds of being infected with A. simplex and/or P. decipiens was 68.6 (95% confidence interval, 11.6-627.7) times higher in marine fish than in anadromous fish, after adjusting for length of fish. Negative binomial models were created for animal species with large enough sample sizes and parasite prevalence estimates to assess risk factors associated with anisakid abundance. In seals, the only risk factor significantly associated with increasing anisakid abundance was increasing length (p < 0.01), while in beluga whales, the only significant risk factor was year of capture (p = 0.03). In fish, length was the variable most commonly associated with increased anisakid larval abundance, with longer fish having significantly higher larval abundances than shorter fish of the same species. The presence of A. simplex and P. decipiens in bearded seals, ringed seals, and beluga whales from Inuit hunting grounds suggests that they likely act as definitive hosts for these parasites in these environments. With respect to zoonotic disease risk associated with Inuit country foods, among the species of fish examined, Atlantic tomcod, polar cod, and sculpins represented the greatest risk of foodborne disease from A. simplex and P. decipiens.
Asunto(s)
Infecciones por Ascaridida/veterinaria , Ascaridoidea/aislamiento & purificación , Enfermedades de los Peces/epidemiología , Mamíferos/parasitología , Zoonosis , Animales , Anisakis/aislamiento & purificación , Regiones Árticas/epidemiología , Infecciones por Ascaridida/epidemiología , Infecciones por Ascaridida/parasitología , Ballena Beluga/parasitología , Canadá/epidemiología , Femenino , Enfermedades de los Peces/parasitología , Peces , Humanos , Inuk , Larva , Masculino , Prevalencia , Factores de Riesgo , Phocidae/parasitología , Zoonosis/epidemiología , Zoonosis/parasitologíaAsunto(s)
Trichinella/aislamiento & purificación , Triquinelosis/veterinaria , Morsas/parasitología , Animales , Ballena Beluga/parasitología , Aves/parasitología , Cetáceos/parasitología , Enfermedades de los Perros/parasitología , Perros/parasitología , Ecosistema , Humanos , Phoca/parasitología , Factores de Riesgo , Sciuridae/parasitología , Phocidae/parasitología , Siberia , Triquinelosis/epidemiologíaRESUMEN
Synthesium pontoporiae n. comb. is redescribed, together with Synthesium tursionis and Synthesium seymouri n. comb.; the parasites were obtained from stranded and accidentally caught cetaceans. The sucker ratio (ratio between widths of the oral and ventral suckers) in S. pontoporiae was 1:1.8-3.0 (mean 1:2.2); in S. tursionis was 1:0.8-1.2; and in S. seymouri was 1:0.5-0.7. Synthesium pontoporiae differed from its congeners by additional diagnostic characters, including: oval to lobed testes; small cirrus with pyriform proximal region and flexible, tubular distal region formed by evagination of ejaculatory duct; and vitellarium in small follicles extending from the level of the seminal vesicle to the posterior extremity of the body and not forming dendritic radial bunches. Data on the morphology of adult S. pontoporiae and S. tursionis were inferred from confocal laser microscopical observations.
Asunto(s)
Cetáceos/parasitología , Parasitosis Intestinales/veterinaria , Trematodos/clasificación , Infecciones por Trematodos/veterinaria , Animales , Ballena Beluga/parasitología , Delfín Mular/parasitología , Parasitosis Intestinales/parasitología , Intestino Delgado/parasitología , Microscopía Confocal/veterinaria , Trematodos/anatomía & histología , Trematodos/ultraestructura , Infecciones por Trematodos/parasitología , Ballenas/parasitologíaRESUMEN
Cryptosporidium spp. and Giardia spp. are protozoan parasites that are often associated with severe diarrheal disease in a variety of mammals. Although these parasites have been extensively studied in terrestrial ecosystems, little is known about either parasite in the marine environment. Therefore, the objective of this study was to determine the prevalence of both Cryptosporidium spp. and Giardia spp. in 5 marine mammal species. Fecal samples were collected from 39 bowhead whales (Balaena mysticetus), 49 North Atlantic right whales (Eubalaena glacialis), 31 ringed seals (Phoca hispida), 22 bearded seals (Erignathus barbatus), and 18 beluga whales (Delphinapterus leucas) between 1998 and 2003. Using an immunofluorescent assay, parasites were detected in the feces of bowhead whales, right whales, and ringed seals, while neither parasite was detected in samples from bearded seals or beluga whales. Overall, prevalences were highest in ringed seals (Cryptosporidium spp., 22.6%; Giardia spp., 64.5%) and right whales (Cryptosporidium spp., 24.5%; Giardia spp., 71.4%) and lowest in bowhead whales (Cryptosporidium spp., 5.1%; Giardia spp., 33.3%). To our knowledge, this is the first report of Cryptosporidium spp. and Giardia spp. in either whale species and of Cryptosporidium spp. in the ringed seal.