Seroepidemiology of abdominal angiostrongyliasis: the standardization of an immunoenzymatic assay and prevalence of antibodies in two localities in Southern Brazil

Abstract

SummaryAbdominal angiostrongyliasis is a nematode disease produced by Angiostrongylus costaricensis, a metastrongylid parasite of wild rodents. Accidental human infection occurs through ingestion of food or water contaminated with third-stage larvae present in the mucous secretion of terrestrial molluscs. An ELISA test was standardized for detection of IgG antibodies recognizing a surface antigen prepared from female worms. Competitive absorption of sera with Ascaris suum crude antigen resulted in a test with 86% sensitivity and 83% specificity. The disease is endemic in Southern Brazil and a number of cases are diagnosed every year through anatomo-pathological examination of biopsies or surgical specimens, since no other diagnostic method is available. According to seroepidemiological studies, prevalences in two transmission foci are 29.8 and 66%, attesting to the widespread occurrence of the infection in those endemic areas. keywords angiostrongyliasis, ELISA, Brazil correspondence C. Graeff-Teixeira, Rua Marquês do Pombal, 799/801, CEP 90540-010,

Diagnosis of abdominal angiostrongyliasis by PCR from sera of patients

“…Immunodiagnostic tests show many difficulties with cross-reacting antibodies, diversity of the humoral reactivity and the eventual persistence of antibodies for several months after the acute phase 4,7 . In this setting, tests for detection of nucleic acids in serum, amplified by the polymerase chain reaction (PCR) may be of great value for the diagnosis of this zoonotic parasitosis.…”

Standardization of a multiplex real-time PCR test for the identification of Angiostrongylus cantonensis, A. costaricensis and A. vasorum

“…Existen pruebas de antígenos, precipitación de partículas en látex, ELISA y una PCR que usa cebadores construidos a partir de secuencias de A. cantonensis, los cuales presentan reacciones cruzadas y carecen de los registros para confirmar su reproducibilidad, sensibilidad y utilidad en el diagnóstico clínico y epidemiológico (9,(36)(37)(38)(39)(40).…”

Use of heterologous antigens for the immunodiagnosis of abdominal angiostrongyliasis by an enzyme-linked immunosorbent assay

“…costaricensis crude antigens have been used for the immunodiagnosis of angiostrongyliasis since 1997 and later in the diagnosis of acute angiostrongyliasis (Graeff-Teixeira et al 1997, Geiger et al 2001. Previously used antibody-based detection systems included precipitation reactions (Sauerbrey 1977) and latex agglutination using crude antigenic preparations; the latter has been used for many years in Costa Rica (Kramer et al 1998).…”