ABSTRACT
BACKGROUND: Neurocysticercosis (NCC) is a neglected tropical disease and its diagnosis is still a challenge due to non-specific manifestations. Neuroimaging techniques are used in the diagnosis of NCC, however, due to the high cost of these methods and the advantages presented in the use of immunological tests, such as ease of performance and satisfactory results, immunoassays are commonly used to detect antibodies against Taenia sp. antigens. The aim of the present study was to produce, characterize and apply specific polyclonal immunoglobulin Y (IgY) anti-Taenia crassiceps extracted from egg yolk of hens immunized with T. crassiceps metacestodes. METHODS: Indirect enzyme-linked immunosorbent assay (ELISA), avidity ELISA, immunoblotting and indirect immunofluorescence tests were performed for characterization of IgY antibodies. Diagnostic performance was verified by ELISA for immune complex detection testing 90 serum samples. RESULTS: Values of sensitivity, specificity, positive and negative likelihood ratios (LR+/LR-) and area under the curve (AUC) were calculated and presented the following results: sensitivity 83.3%, specificity 96.7%, AUC 0.966, LR+ 25.0 and LR- 0.17. CONCLUSIONS: Results of this pioneering and innovative study demonstrate that anti-T. crassiceps IgY antibodies present potential applicability and can be used as an efficient tool in human NCC serodiagnosis.
Subject(s)
Neurocysticercosis , Animals , Antibodies, Helminth , Antigen-Antibody Complex , Antigens, Helminth , Chickens , Egg Yolk , Enzyme-Linked Immunosorbent Assay , Female , Humans , Immunoglobulins , Neurocysticercosis/diagnosis , Sensitivity and SpecificityABSTRACT
Strongyloides stercoralis causes chronic asymptomatic infections in immunocompetent human hosts and systemic invasion in immunocompromised patients, developing into a fatal hyperinfection syndrome. IgA and IgG detection in saliva and serum paired samples were tested using total saline extract from Strongyloides venezuelensis (SE(*)) and its detergent phase (D) extracted with Triton X-114. Saliva and serum paired samples were obtained from: 25 patients with confirmed strongyloidiasis; 25 patients with other parasitoses and 20 from apparently healthy individuals. Sensitivity, specificity, diagnostic efficiency, positive and negative predictive values and likelihood ratio were calculated at the optimum point of reaction. Using D phase sensitivity and specificity to detect IgA in saliva were 76.0% and 88.9% and in serum 80.0% and 86.7%, respectively. To detect IgG, D phase showed sensitivity and specificity of 88.0% and 88.9% in saliva and 88.0% and 84.4% in serum, respectively. D phase proved to be specific and efficient and could be utilized as an alternative antigen for IgA and IgG detection in saliva and serum samples for strongyloidiasis diagnosis.
Subject(s)
Antigens, Heterophile/immunology , Immunoglobulin A/immunology , Immunoglobulin G/immunology , Strongyloidiasis/immunology , Animals , Antibodies, Helminth/blood , Antibodies, Helminth/immunology , Antigens, Heterophile/chemistry , Detergents/chemistry , Feces/parasitology , Humans , Immunoglobulin A/blood , Immunoglobulin G/blood , Parasitic Diseases/immunology , Parasitic Diseases/parasitology , Rats , Saliva/immunology , Saliva/parasitology , Sensitivity and Specificity , Strongyloides/immunology , Strongyloides stercoralis/immunology , Strongyloidiasis/blood , Strongyloidiasis/diagnosisABSTRACT
The objective of this study was to determine the presence of Strongyloides stercoralis in urban garbage collectors through the use of immunological and parasitological methods. A total of 92 individuals were evaluated from August, 1997, to June, 1998. For the parasitological diagnosis Baermann and Lutz' methods were applied. The immunological diagnosis involved the indirect fluorescence antibody test (IFAT) and the enzyme-linked immunosorbent assay (ELISA) to detect specific IgG antibodies. Of the 92 workers examined, six (6.5 percent) were infected with larvae of S. stercoralis. The IFAT detected 19 (16.3 percent) and the ELISA 17 (18.5 percent) positive serum samples. The differences between the results of parasitological and immunological methods were statistically significant (p<0.05). These results demonstrate that there is a need to improve the health conditions of this category of city employees.