title: Improved diagnosis of Strongyloides stercoralis using recombinant antigen-based serologies in a community-wide study in northern Argentina.
abstract: The serodiagnosis of Strongyloides stercoralis infection by enzyme-linked immunosorbent assays based on crude antigen (CrAg-ELISA), while useful, has been limited by the reliance on crude parasite extracts. Newer techniques such as the luciferase immunoprecipitation system assay (LIPS), based on a 31-kDa recombinant antigen (termed NIE) from S. stercoralis and/or the recombinant antigen S. stercoralis immunoreactive antigen (SsIR), or the NIE-ELISA have shown promise in controlled settings. We compared each of these serologic assays in individuals from both regions of the world in which S. stercoralis is endemic and those in which it is not. A comprehensive stool evaluation (sedimentation concentration, Baermann concentration with charcoal cultures, agar plate, and Harada-Mori) and four different serologic techniques using CrAg-ELISA or recombinant NIE-ELISA as well as LIPS using NIE alone or in combination with a second recombinant antigen (NIE/SsIR-LIPS) were compared among individuals with parasitologically proven infection (n = 251) and healthy controls from regions of the world in which the infection is nonendemic (n = 11). Accuracy was calculated for each assay. The prevalence of S. stercoralis infection was 29.4% among Argentinean stool samples (n = 228). Sedimentation concentration and Baermann were the most sensitive stool-based methods. NIE-LIPS showed the highest sensitivity (97.8%) and specificity (100%) of the serologic assays. The calculated negative predictive value was highest for both the NIE-LIPS and CrAg-ELISA (>97%) irrespective of disease prevalence. No cross-reactivity with soil-transmitted helminths was noted. NIE-LIPS compares favorably against the current CrAg-ELISA and stool evaluation, providing additional accuracy and ease of performance in the serodiagnosis of S. stercoralis infections irrespective of disease prevalence.
authors.affiliation: Area de Investigaciones Clinicas, Fundacion Huesped., Pje. Peluffo 3932, Buenos Aires, Argentina. alekrol@huesped.org.ar
authors.forename: Alejandro J
authors.initials: AJ
authors.lastname: Krolewiecki
authors.forename: Roshan
authors.initials: R
authors.lastname: Ramanathan
authors.forename: Valeria
authors.initials: V
authors.lastname: Fink
authors.forename: Isabel
authors.initials: I
authors.lastname: McAuliffe
authors.forename: Silvana P
authors.initials: SP
authors.lastname: Cajal
authors.forename: Kimberly
authors.initials: K
authors.lastname: Won
authors.forename: Marisa
authors.initials: M
authors.lastname: Juarez
authors.forename: Adriana
authors.initials: A
authors.lastname: Di Paolo
authors.forename: Laura
authors.initials: L
authors.lastname: Tapia
authors.forename: Norma
authors.initials: N
authors.lastname: Acosta
authors.forename: Rogan
authors.initials: R
authors.lastname: Lee
authors.forename: Patrick
authors.initials: P
authors.lastname: Lammie
authors.forename: David
authors.initials: D
authors.lastname: Abraham
authors.forename: Thomas B
authors.initials: TB
authors.lastname: Nutman
mesh_terms: D000293:Adolescent; D000328:Adult; D000818:Animals; D000909:Antibodies, Helminth / Q000097:blood*; D000947:Antigens, Helminth / Q000235:genetics; D001118:Argentina; D002648:Child; D002675:Child, Preschool; D005243:Feces / Q000469:parasitology; D005260:Female; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D010274:Parasitology / Q000379:methods*; D011994:Recombinant Proteins / Q000235:genetics; D012680:Sensitivity and Specificity; D012698:Serologic Tests / Q000379:methods; D017171:Strongyloides stercoralis / Q000276:immunology*; D013322:Strongyloidiasis / Q000175:diagnosis*; D055815:Young Adult
chemical_list: D000909:Antibodies, Helminth; D000947:Antigens, Helminth; D011994:Recombinant Proteins