Serological diagnosis of neurocysticercosis: evaluation of ELISA tests using cyst fluid and other components of Taenia solium cysticerci as antigens

Abstract

An ELISA system was developed to assist with the diagnosis of neurocysticercosis. Antigens were prepared from the fluid, the protoscolex and the cyst wall of cysticerci dissected from infected pigs. The fluid antigen was tested both fresh and after freeze-drying and one year's storage. Sera from patients with proven neurocysticercosis were most reactive using the fluid and least reactive using the cyst wall antigens. Freeze-drying and prolonged storage of fluid antigen did not reduce its reactivity and repeated testing of sera with this antigen gave optical density values within 15% of the original value. Using this ELISA system positive results were obtained from all patients with active neurocysticercosis. Sera from patients with calcified cysts were usually non-reactive or marginally reactive to the fluid antigen.

PESQUISA DE ANTICORPOS CONTRA <i>Cysticercus bovis</i>, POR TESTE ELISA EM BOVINOS DE ABATEDOURO

“…Quando se analisou os animais positivos segundo o estádio evolutivo do cisticerco observou-se, para o teste imunoenzimático, uma sensibilidade de 81,6% para cistos vivos, 84,1% para cistos caseosos e de 85,1% para cistos calcificados (Tabelas 2 e 3). A prova ELISA segundo Bailly et al (1988) tem alta sensibilidade variando de 75% a 90%. Portanto, os dados obtidos (81,6 a 85,1%) estão dentro do esperado.…”

“…No Brasil o Serviço de Inspeção Federal (SIF) fiscaliza em torno de 49% da carne consumida pela população. Todavia, na inspeção de rotina podem não ser detectados de 25 a 50% dos animais afetados, particularmente nos casos de infecção leve (Greets et al, 1980;Cabaret et al, 2002;Minozzo et al, 2004). Se levarmos em consideração a probabilidade de detecção, de acordo com o número de cistos (4% de probabilidade para um cisto), o método "corta e olha" não é hábil para detectar todos os animais parasitados, e a maioria dos cistos continua na musculatura, servindo de fonte de infecção para humanos.…”

Antibodies to the metacestode of taenia solium in the saliva from patients with neurocysticercosis

“…The finding of anticysticercus IgG antibodies in cerebrospinal fluid (CSF) and serum by means of enzyme-linked immunosorbent assay (ELISA) provides a valuable aid for the diagnosis of NC (7)(8)(9)(10). Moreover, the use of ELISA in epidemiological surveys may help to identify high-risk communities where the population could benefit from the introduction of preventive measures aimed at interrupting the parasite's life cycle (1 1).…”

Tropical medicine

“…87 Limited evidence suggests that antigen derived from cysticercal fluid possesses far greater reactivity than that from the cyst-wall. 88 An indirect haemagglutination test has proved useful, but negative results certainly do not rule out active infection.79 '89 An ELISA with sensitivity which varied between 61% and 79% was documented in 1982,86,°but cross-reactions with hydatid and schistosomal infections, proved troublesome. A group in Mexico considered that serological tests for neurocysticercosis still lacked reliability.9' However, when antigen from Cysticercus cellulosae fluid is available, the ELISA now produces results which are both sensitive and specific.88 Experience with serum and cerebrospinal fluid testing using an ELISA designed to detect IgG antibodies against C. cellulosae and T. solium antigens has been reported from Columbia,92 Mexico,86'93'94 Durban, South Africa95 and Brazil.…”