Artículos de revistas
Infecção aguda fatal por Toxoplasma gondii em macaco-barrigudo (Lagothrix lagotricha) - relato de caso
Fecha
2009Registro en:
Clínica Veterinária, São Paulo, v. 14, n. 81, p. 100-104, 2009
1413-571X
Autor
MALUENDA, Ana Carolina Holanda
CASAGRANDE, Renata Assis
NEMER, Viviane Cristhiane
KANAMURA, Cristina Takami
KLUYBER, Danilo
TEIXEIRA, Rodrigo Hidalgo Friciello
MATUSHIMA, Eliana Reiko
Institución
Resumen
A infecção por Toxoplasma gondii é um problema para a manutenção de primatas não humanos em cativeiro, sendo as espécies do Novo Mundo altamente suscetíveis à doença. O objetivo deste trabalho é relatar um caso de toxoplasmose aguda em um macaco-barrigudo (Lagothrix lagotricha) adulto, proveniente de vida livre, que morreu e foi encaminhado para necropsia. Os principais achados anatomopatológicos estavam no pulmão, baço, fígado e linfonodos, com a visualização de estruturas compatíveis com T. gondii no exame citológico, histopatológico e na imunomarcação positiva com anticorpo policlonal anti-T. gondii – achados esses que condizem com os casos encontrados na literatura. Como os primatas neotropicais normalmente desenvolvem infecção aguda e fatal, ressalta-se a importância do manejo preventivo e suas possíveis vias de transmissão em cativeiro The protozoan Toxoplasma gondii is one of the most common parasitic infections of man and other warm-blooded animals. Toxoplasma gondii is a coccidian obligate intracellular parasite, with a sexual cycle (enteroepithelial cycle) in the definitive host (domestic cats and other member of the Felidae family) and an asexual cycle (extraintestinal cycle) in intermediate hosts (man, many mammals and birds). There are three infections stages of T. gondii for all animals: tachyzoites (individually and in groups), bradyzoites (in tissue cysts), and sporozoites (in oocysts). This protozoan represents a problem for the maintenance of non-human primates in captivity, especially the New World primates that are highly susceptible to this infection. The objective of the present study is to report an acute toxoplasmosis case in an adult free-living woolly monkey (Lagothrix lagotricha) that was sent by IBAMA from Roraima State to Criadouro Conservacionista Toca da Raposa in São Paulo State. This monkey was lethargic, anorexic, and it died two days later. This dead animal was sent to the Animal Pathology Laboratory at University of São Paulo for post-mortem examination. Necropsy revealed cachexia, pale mucous membrane, heterogeneous red-colored and consolidated lungs, severe splenomegaly, mild hepatomegaly and enlarged and red-colored lymph nodes, mainly mesenteric. The cytology exam by imprint of the lungs, liver, spleen and mesenteric lymph nodes showed compatible T. gondii tachyzoites free or in macrophages (individually or in small groups). Sections of all tissues were collected, fixed in 10% buffered neutral formalin for 48 hours, embedded in paraffin, sectioned at 4µm, stained with hematoxylin and eosin, and submitted to a light microscopy examination. Histopathologically, exams revealed nonsuppurative, acute, diffuse, severe pneumonia; nonsuppurative, multifocal, mild myocarditis; nonsuppurative, moderate hepatitis with severe, multifocal necrosis; interstitial, nonsuppurative, multifocal, moderate nephritis. The spleen presented lymphoid depletion and moderate necrosis with haemorrhage and histiocitic splenitis. In the lymph nodes, which were mainly mesenteric, multifocal to coalescing severe necrosis with haemorrhage was observed, as well as moderate diffuse histiocitic lymphadenitis. Intralesion, individual or in small groups, T. gondii tachyzoites were visualized free or within macrophages in the lungs, liver, spleen and lymph nodes. Paraffin-embedded tissue blocks were sent to the Immunohystochemistry Laboratory at Adolfo Lutz Institute. Immunohystochemistry (IHC) was performed with the streptavidin-biotin peroxidase technique and the use of polyclonal antibodies against T. gondii. IHC showed a specific antigen-antibody reaction which was very intense in the lungs, liver, spleen, lymph nodes, moderate in the kidneys, and mild in the central nervous system, heart, and adrenal glands. These findings were in accordance with the lesions reported in literature. Toxoplasmosis is considered to be a fatal parasitic disease in some animals, such as New World primates. This disease is one of the main diseases in New World primates, and there are many outbreaks in zoos and private breeders in Brazil and in other countries. According to literature, free-living New World primates (Cebus spp and Alouatta spp) have had antibodies against T. gondii. They are much more susceptible than Old World primates, rarely surviving the disease. The reasons for such high susceptibility are not clear; however, data suggested that, due to their arboreal habits, these primates were isolated, during their evolution, from both felids and T. gondii oocysts; as a result, they failed to develop a resistance to toxoplasmosis. Moreover, data suggest that vertebrates of this type do not develop an effective cellular immune response to T. gondii. Normally, New World primates die without premonitory signs having been observed, indicating the acute nature of the disease. If the clinical signs are present, they are not specific, such as lethargy, malaise, anorexia, and the animals die in few days In previous reports and in the present study, the gross and microscopic lesions were similar. These lesions were characterized by necrosis in the lungs, liver, spleen, mesenteric lymph nodes, and absent or variable lesions in the gastroenteric system. The presence of the tachyzoites or cysts of bradyzoites was detected in the histology, mainly in the lesion or associated with inflammatory cell infiltration. Toxoplasma gondii may be transmitted by the consumption of infected meat, by the oral-faecal route, or congenitally. Experimental studies indicated the possibility of aerosol transmission of T. gondii to squirrel monkeys (Saimiri sciureus) 6. In many cases described in literature, the route of T. gondii transmission to New World primates was not identified. It was then assumed that transmission had occurred by ingestion of infected raw meat or food or drink contaminated with sporulated oocysts. As New World primates usually develop acute and fatal infection, this fact militates against the use of therapeutic measures, and it is important to emphasize the need for rigorous prophylactic procedures to prevent the occurrence of these parasites in captive colonies La infección por Toxoplasma gondii representa un problema en el mantenimiento en cautiverio de los primatas no humanos, siendo que las especies del nuevo mundo son muy susceptibles a la enfermedad. El objetivo de este trabajo es relatar un caso de toxoplasmosis aguda en un mono lanudo (Lagothrix lagotricha) adulto, originario de vida libre, enviado para necropsia despues de haber muerto en un periodo de dos dias. Los principales hallazgos anatomopatologicos fueron encontrados en el pulmón, bazo, hígado y ganglios linfáticos, con visualización de extructuras compatibles con T. gondii por la citología, histopatología y imunomarcación positiva con anticuerpo policlonal anti-T. gondii; estos hallazgos son iguales a los descriptos en la literatura. Como los primates neotropicales normalmente desenvueven infección aguda y fatal, se destaca la importancia del manejo
preventivo y sus posibles vías de transmisión