RESUMEN
Histomoniasis, caused by the protozoan, Histomonas meleagridis, is an economically important disease of turkeys, and it also affects several other species of domesticated and wild Galliformes, including chickens. Under natural conditions, the parasite is transmitted through eggs of a nematode, Heterakis gallinarum, that shares its hosts with Hi. meleagridis. The protozoan infects tissues of both male and female He. gallinarum and eventually is carried within the worm egg. Histomonas meleagridis more readily infects and develops in chickens, and the proximity of chicken farms is a major risk factor for outbreaks in turkeys. Chemoprophylaxis had controlled Hi. meleagridis in turkeys very successfully, but histomoniasis has recently reemerged in turkeys because anti-histomonal drugs are no longer permitted by the United States Food and Drug Administration because of the concerns for residual toxins in poultry meat. Horizontal transmission of the protozoan in the absence of worm eggs remains a mystery because the flagellate trophozoite excreted in the feces of turkeys is not viable for any length of time. A proposed resistant stage of the protozoan has not yet been conclusively demonstrated. Here we review the discovery of the protozoan and the current status of the disease and its control.
Asunto(s)
Enfermedades de las Aves de Corral , Infecciones Protozoarias en Animales , Pavos , Animales , Pavos/parasitología , Enfermedades de las Aves de Corral/parasitología , Enfermedades de las Aves de Corral/historia , Enfermedades de las Aves de Corral/epidemiología , Enfermedades de las Aves de Corral/transmisión , Infecciones Protozoarias en Animales/epidemiología , Infecciones Protozoarias en Animales/parasitología , Infecciones Protozoarias en Animales/historia , Infecciones Protozoarias en Animales/transmisión , Estados Unidos/epidemiología , Historia del Siglo XX , Trichomonadida/aislamiento & purificación , Femenino , Masculino , Historia del Siglo XXIRESUMEN
The bionomy of Chelopistes meleagridis off the host was observed with the aim of better understanding the aspects of this species' life cycle. For this purpose, C. meleagridis adults were collected and maintained under controlled conditions to reproduce (35°C and RH > 80%), with turkey feathers as the food source. From the offspring of these lice, the development of 150 individuals was observed from the egg to the adult phase. These eggs were divided into two groups of 75 each. After hatching, one group was given a diet composed of feathers while the other received feathers plus skin of the host turkey (Meleagris gallopavo). The “feather + skin” diet resulted in the greatest number of adults, so this diet was given to the next generation of lice reared in vitro, starting from the first instar, to observe their fertility, fecundity and longevity. High reproduction rates were found in relation to other lice of the Ischnocera sub-order, particularly the number of eggs per day and number of eggs produced per female over the lifetime (means of 2.54 and 26.61 eggs, respectively, for wild females and 2.11 and 29.33 eggs for laboratory-reared females). The inclusion of skin in the diet was a determining factor for development to the adult stage, since 48% of the lice fed this diet reached that stage, versus 1.3% that reached maturity fed only with feathers. The development time of the males and females was similar (mean of 29.38 days), without any difference in the sexual proportion of the adults.
A bionomia de Chelopistes meleagridis fora do hospedeiro foi observada com o objetivo de compreender aspectos relacionados ao ciclo de vida desta espécie. Para isto, adultos de C. meleagridis foram coletados e colocados em condições controladas (temperatura de 35°C e umidade relativa superior a 80%) para se reproduzir, oferecendo-se pena como alimento. Da prole destes adultos, foi observado o desenvolvimento de 150 indivíduos desde o ovo até a fase adulta. Para 75 destes, foi oferecida a dieta composta de pena, enquanto para os outros 75 a dieta foi composta de pena e pele do hospedeiro (peru, Meleagris gallopavo). Ao verificar que a dieta “pena + pele” foi a que resultou no maior número de adultos, foram observadas a fertilidade, fecundidade e a longevidade de piolhos criados in vitro desde o primeiro ínstar alimentados com esta dieta. Valores altos relacionados à reprodução desta espécie foram encontrados em relação a outros piolhos da subordem Ischnocera, destacando-se: número de ovos produzidos por dia e número de ovos produzidos por fêmeas durante a vida (médias de 2,54 e 26,61 ovos, respectivamente, para fêmeas selvagens e 2,11 e 29,33 ovos, respectivamente, para fêmeas criadas in vitro.). A inclusão de pele na dieta foi determinante para o desenvolvimento até o estágio adulto, uma vez que 48% dos piolhos alimentados com essa dieta atingiram a fase adulta. Quando foi oferecido apenas pena, 1,3% dos piolhos atingiram a maturidade. O tempo de desenvolvimento de machos e fêmeas foi semelhante (média de 29,38 dias) sem haver diferença na proporção sexual dos adultos.
Asunto(s)
Animales , Femenino , Masculino , Ischnocera/fisiología , Estadios del Ciclo de Vida/fisiología , Dieta , Ischnocera/clasificación , Ischnocera/crecimiento & desarrollo , Laboratorios , Reproducción/fisiología , Pavos/parasitologíaRESUMEN
Duas especies de cestóides em perus, Meleagris gallopavo (Galliformes, Phasianidae), no Brazil: patologia induzida por Hymenolepis cantaniana e ocorência de Raillietina tetragona. A patologia induzida em perus pelo cestóide H. cantaniana é descrita, com dados sobre prevalência, intensidade media e amplitude das cargas parasitarias. H. cantaniana ocorreu com urna prevalência de 5.0 por cento nas 40 aves examinadas, com intensidade media de 17.5 e amplitude de 14-21 espécimes de cestóides. Não foram observadas lesões macroscópicas nos perus parasitados. As lesões provocadas por H. cantaniana eram representadas, principalmente, ou por múltiplos segmentos dos parásitos, acompanhados por discreta reação inflamatoria mista com a presera de células mononucleares e heterófilos, ou por severos processos inflamatorios transmurais, caracterizados pela presera de células mononucleares, ao longo das carnadas muscular e serosa das vilosidades e criptas intestinais. Estes representam os primeiros achados patológicos relacionados a presera de cestóides em perus a serem relatados no Brasil. Raillietina tetragona, não patogênica para as aves investigadas, ocorreu com baixa prevalência e amplitude de infecção de 2.5 por cento e 1-2 parásitos, respectivamente.
The pathology induced in turkeys (Meleagris gallopavo) by one cestode species Hymenolepis cantaniana is described together with data on prevalence, mean infection and range of worm burdens. H. cantaniana occurred with a prevalence of 5.0 percent in the 40 examined hosts in a range of 14-21 specimens and a mean intensity of 17.5. Gross lesions were not observed in the parasitized birds. Lesions due to H cantaniana mainly consisted of multiple segments of parasites, together with a mild mixed inflammatory reaction with the presence ofmononuclear cells and heterophils or severe transmural inflammatory processes, characterized by the presence ofmononuclear cells along the muscular and serosa layers of the intestinal villi and crypts. These are the first pathological findings related to the presence ofcestodes in turkeys to be reported in Brazil so far. Raillietina tetragona, not pathogenic to the present investigated turkeys, occurred with a low prevalence and range of infection of 2.5 percent and 1-2 worms, respectively.
Asunto(s)
Masculino , Animales , Femenino , Enfermedades de las Aves/parasitología , Infecciones por Cestodos/epidemiología , Infecciones por Cestodos/patología , Pavos/parasitología , Brasil/epidemiología , Enfermedades de las Aves/epidemiología , Enfermedades de las Aves/patología , Infecciones por Cestodos/veterinaria , PrevalenciaRESUMEN
The pathology induced in turkeys (Meleagris gallopavo) by two capillariid nematodes, Baruscapillaria obsignata and Eucoleus annulatus is described together with data on prevalences, mean infection and range of worm burdens. B. obsignata occurred with a prevalence of 72.5 percent in the 40 examined hosts in a range of 2-461 nematodes and a mean intensity of 68.6, whereas E. annulatus was present in 2.5 percent of the animals, with a total amount of five recovered parasites. Gross lesions were not observed in the parasitized birds. Lesions due to B. obsignata mainly consisted of the thickening of intestinal villi with a mild mixed inflammatory infiltrate with the presence of mononuclear cells and heterophils. The lesions induced by E. annulatus were represented by foci of inflammatory infiltrate with heterophils in the crop epithelium and esophagus of a single infected female. These are the first pathological findings related to the presence of capillariid worms in turkeys to be reported in Brazil so far. Capillaria anatis, although present, was not pathogenic to the investigated turkeys.
Asunto(s)
Animales , Femenino , Masculino , Infecciones por Nematodos/veterinaria , Pavos/parasitología , Brasil , Infecciones por Nematodos/parasitología , Infecciones por Nematodos/patología , Recuento de Huevos de Parásitos , Índice de Severidad de la EnfermedadRESUMEN
The prevalence of infection and associated pathology induced by two helminth and one protozoan species infecting Brazilian turkeys are reported. The intestinal nematode Heterakis gallinarum appeared with a prevalence of 70 percent in the infected birds, without gross lesions when not associated to the protozoan Histomonas meleagridis. Histological findings in the ceca were represented by the presence of H. gallinarum worms, intense chronic diffuse inflammatory processes with mononuclear and polymorphonuclear (heterophils) leucocyte infiltrations. The prevalence of the protozoan H. meleagridis associated to H. gallinarum was of 2.5 percent and microscopic examination revealed a severe inflammatory process in the liver and cecum with the presence of small clear areas with round eosinophilic parasites. Gross lesions were absent in turkeys infected with the renal digenetic trematode Paratanaisia bragai; the parasite was prevalent in 20 percent of the cases and cross-sections of the kidneys showed a remarkable distension of the collecting ducts with several worms in the lumen. The walls of the ducts presented a discrete heterophilic infiltrate among mononuclear cells.
Asunto(s)
Animales , Femenino , Masculino , Infecciones por Nematodos/veterinaria , Infecciones Protozoarias en Animales/epidemiología , Infecciones por Trematodos/veterinaria , Pavos/parasitología , Brasil/epidemiología , Infecciones por Nematodos/epidemiología , Infecciones por Nematodos/patología , Prevalencia , Infecciones Protozoarias en Animales/patología , Infecciones por Trematodos/epidemiología , Infecciones por Trematodos/patologíaRESUMEN
Relata-se o primeiro caso de infecção de perus, Meleagris gallopavo, por Cheilospirura hamulosa no Brasil, com base no achado de três espécimes fêmeas de C. hamulosa, inseridos na submucosa da moela de um peru, retirado de um lote de 15 aves, provenientes de criadouros domésticos no estado de Minas Gerais. A ocorrência foi de 6,7 por cento. A ave parasitada não apresentava sinais clínicos. As lesões microscópicas da moela eram severas, caracterizando-se por intensos processos inflamatórios crônicos e difusos, com infiltrados mistos de granulócitos, estendendo-se à mucosa e às camadas musculares. Nessa área, foram observados fragmentos dos parasitos e perfuração da mucosa, com destruição das camadas musculares.