Serodiagnosis of Human Strongyloidiasis in Brazil and Peru Using Strongyloides venezuelensis Antigens: A Comparative Study in Endemic Settings
William Henry Roldán, Marcelo Andreetta Corral, Dirce Mary Correia Lima Meisel, Marco Canales, Maria Angelica Terashima, Silvia Vanessa Lourenço, Ronaldo Cesar Borges Gryschek, Fabiana Martins de PaulaABSTRACT
Strongyloidiasis is a neglected tropical disease caused by the soil‐transmitted helminth Strongyloides stercoralis . Immunological assays employing heterologous antigens from Strongyloides venezuelensis represent a valuable alternative to parasitological diagnosis. In this study, we evaluated the diagnostic performance of different antigenic preparations derived from S. venezuelensis infective larvae (L3) for the detection of anti‐ Strongyloides IgG antibodies in sera from Brazilian and Peruvian individuals. Total soluble (S‐L3), membrane (M‐L3), cuticular (C‐L3) and excretory/secretory (ES‐L3) antigenic extracts were assessed using enzyme‐linked immunosorbent assay (ELISA). Overall, Brazilian sera showed higher reactivity than Peruvian sera to all antigenic preparations. Both S‐iL3 and ES‐L3 demonstrated excellent diagnostic performance with samples from both countries, showing 100% sensitivity and specificities of 97.4% and 100%, respectively. When a single cut‐off value applicable to both populations was adopted, S‐L3 showed the best overall performance, achieving 100% sensitivity and 98.7% specificity at a cut‐off of 0.367, or 97.5% sensitivity and 100% specificity at a cut‐off of 0.416, followed by ES‐L3, C‐L3 and M‐L3. Heterologous antigenic extracts from S. venezuelensis , particularly S‐L3, may represent a useful alternative for the serological diagnosis of S. stercoralis infection in endemic settings such as Brazil and Peru.