A comparative study on IgG-ELISA, IgM-IFT and Kato-Katz methods for epidemiological purposes in a low endemic area for schistosomiasis

Abstract

The high sensitivity and the possibility of automation of the enzyme-linked-immunosorbent-assay (ELISA)

Schistosomiasis mansoni: follow-up of control program based on parasitologic and serologic methods in a Brazilian community of low endemicity

“…The presence o circulating antibodies in 13 individuals, who were treated for more than 5 years, might suggest failure in the treatment, with maintenance of a low infection not detected for the parasitologic examination, re-exposure of these individuals to cercaria, without establishment of infection, or cross reactions because contact with other parasites. The occurrence of cross-reactions with antigens of other helminth species like Ascaris or Trichuris has not been observed with the control group in the present study, confirming the results obtained previous studies (Kanamura et al 1998).…”

“…The dried blood was eluted from the filter paper by immersing an area of approximately 1 cm 2 in 330 µl of PBS (phosphatebuffered solution, 0.01 M, pH 7.2), and incubating for 18 h at 4°C. The relative serum dilution, after elution and removal of the filter paper, was estimated to be 1:20 (Ferreira & Carvalho 1982), and used for the IgG-IFT and IgM-IFT (Silva et al 1998).…”

“…In these areas the infected individuals use to show low intensity infection, eliminating less than 100 eggs per gram (epg), without clinical symptoms that are compatible with the disease (Dias et al 1992b). Various authors have shown that in such areas, where individuals use to have reduced egg counts, the sensitivity of the parasitologic methods, usually applied in population surveys, is flawed when compared to the serologic methods (Dias et al 1992b, De Vlas & Gryscels 1992, Kanamura et al 1998. There are various studies that assess the potential of different immunodiagnostic methods in populations (Deelder & Kornelis 1981, Dias et al 1992b, Noya et al 1999.…”

“…There are various studies that assess the potential of different immunodiagnostic methods in populations (Deelder & Kornelis 1981, Dias et al 1992b, Noya et al 1999. The immunofluorescence test (IFT) is a serological technique successfully applied as diagnostic tool in epidemiologic studies of schistosomiasis mansoni, in the state of São Paulo (Kanamura et al 1998).…”

Evaluation of microscopical and serological techniques in the diagnosis of Schistosoma mansoni infection at Sennar State, Central Sudan

“…Earlier in a study in Ethiopia, the sensitivity and specificity of the ELISA test were 97.6% and 30.3%, respectively [29] . Despite the serological tests like ELISA are not able to discriminate between previous contact with the parasite and active infections [30] , the high sensitivity ELISA has indicated this technique as one of the most successful serological tests for epidemiological studies to detect parasite burden [30,31] . In areas of endemicity, other researchers have suggested to carry out serological tests that require high specificity to avoid false-positive results.…”