Aspectos macroscópicos e histológicos da cisticercose bovina

Abstract

ABSTRACT.-Panziera W., Vielmo A., Bianchi R.M., Andrade C.P., Pavarini S.P., Sonne L., Soares J. Bovine cysticercosis is an important zoonotic parasitic disease with high prevalence in several regions of Brazil. Considering the need of improvement of the accuracy of diagnosis of these lesions, as well as the difficulty of classification of the cysts, this study aimed to correlate gross and histopathological changes of bovine cysticercosis and to use polymerase chain reaction (PCR) as an aid in their identification. Cystic and nodular lesions from cattle, grossly compatible with cysticercosis, were sampled in slaughterhouses from Rio Grande do Sul State. Lesions were allotted in one of the following groups. Group 1: viable cysticercus; Group 2 (subdivided 2a e 2b): degenerating cysticercus with a potentially viable scolex; and Group 3: dead cysticercus (mineralized). The gross and microscopic aspects of every cysticerci of each group were compared. Two hundred and thirty two cysts and nodules compatible with cysticercus were sampled from 127 bovine. Twenty six of those lesions were tested with PCR. Out of 127 cattle, 46 (36.2%) had more than one cyst and the remaining 81 (63.8%) had on cyst each. Myocardium was the most frequently involved anatomical site (55.9%), followed by masseter muscle (22.8%). When there was more than one organ involved in the same bovine, myocardium a master muscle sum up 11 cases (8.6%). In general, the average of cysticercosis frequency was 10-15%. However the average in some cattle lots was in excess of 50%, 80% and 90%. Morphologically, 232 cysticerci were classified in three groups. In Group 1, 23 cysticerci (9.9%) were considered viable and were characterized by cysts of translucent or slightly opaque wall, containing clear and a white point (scolex) within the cyst. Histologically, the cysts consisted of a membrane from which a scolex of Taenia saginata invaginated. One hundred and fifty six cysts (67.2%) were allotted in Group 2; grossly these cysts revealed two different morphological patterns. In 111 (71.1%) cases of Group 2 (Group 2a) nodular caseous lesions were observed. Histologically, the cysts were characterized by nodules consisting by a central area containing the scolex and membrane, both degenerated, and caseous necrosis. In the remaining 45 (28.9%) cases of Group 2 (Group 2b), lesions were also caseous; however, at cut surface the cysts had a central hole amidst the caseous material. The microscopic aspect of the 45 cysts included in the second was similar to that of the first pattern. However in eight (17.8%) of the 45 cysts only a viable parasitic membrane was observed and in one cyst the membrane and viable scolex were observed. In the remaining 36 cases (80%), the cysts consisted of a central area containing both degenerated membrane and scolex, and caseous necrosis. In Group 3, 53 dead cysts (mineralized) (22.9%) were found among the total of 232 cysts. The 1 Recebido em 20 de fevereiro de 2017.Aceito para publicação em 28 de março de 2017.

Atypical parasitic lesions in slaughtered cattle in Southern Brazil

“…Similar data have been described in humans, in which cardiac involvement is rare and usually affects the left ventricle (Uygur et al, 2017), being a result of myocardial seeding with hexacanth embryos, which can be deposited by means of the coronary circulation (Pasaoglu et al, 1992). This condition should also be differentiated from cysticercosis in cattle, which may be achieved by the gross observation of lesions, since cysticercosis lesions are usually smaller when compared to hydatid cysts, and viable cysticerci constantly present a central scolex (Panziera et al, 2017). The identification of the viable hydatids in this study was simple, since the parasitic structures were preserved.…”

“…Heart and skeletal muscles are sites routinely inspected for the diagnosis of cysticercosis (Cysticercus bovis/ cysticercus of Taenia saginata), which facilitates the detection of lesions. Occasionally, degenerate cysticercosis constitutes the main differential diagnosis for this condition, mainly when eosinophilic myositis forms small nodules (Panziera et al, 2017). However, when eosinophilic myositis has this presentation, the nodules are usually multiple and in close proximity, what is not observed in cysticercosis (Cooper & Valentine, 2016).…”

Relationship between early finishing and reduced prevalence of cysticercosis in cattle

“…Infection of humans with T. saginata is common in areas where sanitation is inadequate (USIP et al, 2011;ACEVEDO-NIETO et al, 2012). This parasite is commonly found in South America, North America, and Africa (USIP et al, 2011), with high prevalence in several regions of Brazil (PANZIERA et al, 2017) and mainly in economically impoverished areas.…”