A COMPARATIVE EPIDEMIOLOGIC STUDY OF SPECIFIC ANTIBODIES (IgM AND IgA) AND PARASITOLOGICAL FINDINGS IN AN ENDEMIC AREA OF LOW TRANSMISSION OF Schistosoma mansoni

Abstract

The diagnostic potential of circulating IgM and IgA antibodies against Schistosoma mansoni gut-associated antigens detected by the immunofluorescence test (IFT) on adult worm paraffin sections was evaluated comparatively to the fecal parasitological method, for epidemiological purposes in low endemic areas for schistosomiasis. Blood samples were collected on filter paper from two groups of schoolchildren living in two different localities of the municipality of Itariri (São Paulo, Brazil) with different histories and prevalences of schistosomiasis. The parasitological and serological data were compared to those obtained for another group of schoolchildren from a non-endemic area for schistosomiasis. The results showed poor sensitivity of the parasitological method in detecting individuals with low worm burden and indicate the potential of the serological method as an important tool to be incorporated into schistosomiasis control and vigilance programs for determining the real situation of schistosomiasis in low endemic areas.

Advances in the Diagnosis of Human Schistosomiasis

“…However, intrinsic problems in schistosomiasis immunodiagnosis, such as the difficulty in accurately differentiating between active infection, past infection, and reinfection, remain unresolved. Also, there are inherent specificity problems due to antibody cross-reactivity with different species of schistosomes, including reactivity with cercarial antigens from animal schistosomes, and with other helminth parasites (89)(90)(91).…”

“…The reaction between parasite antigens and antischistosomal antibodies in patient serum or other bodily fluids is the concept behind the IFA, which is performed using adult worm paraffin sections, cercariae, and eggs (120)(121)(122). IFA detection of IgM and IgG antibodies in the acute and chronic stages of schistosomiasis has been used as a sensitive method of diagnosis, especially in low-prevalence areas (90,123,125), in some instances combined with other diagnostic procedures to increase the sensitivity and specificity (111,126). Some limitations of the test, including the need for relatively expensive microscopes and reagents, with appropriate laboratory facilities and technical expertise, hinder its application in community surveys (123,125).…”

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

“…4,13 In Brazil, several techniques have been tested in LEAs, such as São Paulo. 12,15,36,37 In Barra Mansa, as a result of implementation of a special program for controlling schistosomiasis (Programa Especial de Controle da Esquistossomose) in 1976, schistosomiasis prevalence was around 1%. 20 The aim of this study was to compare and evaluate the accuracy of the COPT, IFA-IgM, and parasitological diagnostic techniques in the identification of S. mansoni infections, by means of epidemiological inquiry of randomized fecal and serum samples from individuals living in areas peripheral to Barra Mansa, Rio de Janeiro.…”

“…The specificity of this reaction has also proved to be adequate. 15,16 The periovular reaction has a high sensitivity and specificity for the detection of antibodies against the secretion or excretion antigens of viable Schistosoma mansoni eggs. 4,13,17,18 Although it is a very laborious technique, it is the only antibody detection technique that has been shown to correlate with parasite activity.…”

Prevalence of Anti-Toxoplasma gondii Antibody in Hunter-Killed Wild Boars, Susscrofa leucomystax, on Amakusa Island, Kumamoto Prefecture, Japan

“…Although this method cannot properly measure antibody titer, it is useful to collect samples without syringe and needle. Moreover, this technique is well established and has been applied in field surveys, particularly in tropical areas [3,7]. A previous study has established that storage of the anti-T. gondii antibody on silica gel successfully preserves the activity of the antibody for an extended period [10].…”