Immunological Aspects of Infections with Schistosoma Mansoni

Detection of Schistosoma mansoni Antibodies in a Low-Endemicity Area Using Indirect Immunofluorescence and Circumoval Precipitin Test

“…43,45,46 In this way, the antibodies are detected only when the infection is caused by worms of both sexes. 46,47 However, IFA-IgM techniques may be positive in unisexual infections. 48 The serological positivity detected by IFA-IgM in this study may be related to individuals previously infected with S. mansoni but properly treated and cured 49 or those who were exposed to very low loads of cercariae or unisexual infections.…”

Parasitic Diseases of Man (Recent)

“…The mam malian host produces specific antibodies to three stages of the parasite, viz., cercaria, adult, and egg (244). Complement-fixation and precipitin tests, with antigen from cercarias and adult worms, have been employed for many years (243,244).…”

“…The mam malian host produces specific antibodies to three stages of the parasite, viz., cercaria, adult, and egg (244). Complement-fixation and precipitin tests, with antigen from cercarias and adult worms, have been employed for many years (243,244). Serologic tests with immune sera and living cer carias have caused precipitin reaction with fresh serum (245), and a hood like envelope if the serum is heated (246).…”

“…Serologic tests with immune sera and living cer carias have caused precipitin reaction with fresh serum (245), and a hood like envelope if the serum is heated (246). Cercaria, adult and circumoval precipitins, and cercarial agglutinins have been obtained with serum from S. mansoni patients (244). The cercarial tests are most pronounced in earlier infections; circum oval reactions are more common in sera from chronic cases.…”

Estudo comparativo da acurácia de diferentes técnicas para o diagnóstico laboratorial da esquistossomose mansoni em áreas de baixa endemicidade

“…Fatores relacionados à qualidade da amostra podem ser responsáveis por resultados falsos negativos na RPO, como a presença de hemoglobina no soro devido à hemólise e tempo de estocagem dos soros a -20°C (Mello, 1976 O aparecimento de anticorpos envolvidos na RPO é precoce e coincide com o início da eliminação de ovos nas fezes (Coker, Oliver-Gonzalez, 1957;Senterfit, 1958;Kloetzel, 1959). Dessa forma, os anticorpos detectados pela RPO somente são evidenciados quando a infecção é produzida por vermes de ambos os sexos (Oliver-Gonzalez et al, 1955;Senterfit, 1958) e as técnicas de ELISA-IgG, ELISA-IgM e RIFI-IgM podem ser positivas em infecções unissexuadas (Cheever, 1968 …”