title: Rapid Point-of-Contact Tool for Mapping and Integrated Surveillance of Wuchereria bancrofti and Onchocerca volvulus Infection.
abstract: Elimination programs for Wuchereria bancrofti and Onchocerca volvulus are in critical need of sensitive, specific, and point-of-contact (POC) tools that can be used for surveillance years beyond cessation of mass drug administration when infection intensities are low. Previously, Wb123 and Ov16 were identified individually as potential filarial antigens for an antibody-based POC test. The present study compares single-antigen Wb123- and Ov16-based POC tests with an integrated configuration to detect antibodies to Wb123 and Ov16 simultaneously. Wb123 and Ov16 isolates were striped onto lateral flow strips containing anti-IgG4. Sera from W. bancrofti-, O. volvulus-, and other helminth-infected or -uninfected individuals were added to the strips with buffer. Strips were read for the appearance of a positive or negative test line for both antigens at 20 min and following drying. Sensitivity, specificity, and predictive values were calculated for the single-antigen and biplex strips. Single and biplex lateral flow strips showed nearly identical results, with >90% sensitivity for Ov16 and >92% sensitivity for Wb123. Overall specificities for the single and biplex tests were 98% and 96% for Ov16 and Wb123, respectively. Biplex tests performed as well as the single-antigen tests regardless of the intensity of patient IgG4 response. The high sensitivity and specificity make these new biplex tests extremely useful for POC long-term surveillance following mass drug administration in Africa that should reduce time and cost in areas where bancroftian filariasis and onchocerciasis are coendemic.
authors.affiliation: Laboratory of Parasitic Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, USA.
authors.forename: Cathy
authors.initials: C
authors.lastname: Steel
authors.affiliation: Diagnostics Group, PATH, Seattle, Washington, USA.
authors.forename: Allison
authors.initials: A
authors.lastname: Golden
authors.affiliation: Diagnostics Group, PATH, Seattle, Washington, USA.
authors.forename: Eric
authors.initials: E
authors.lastname: Stevens
authors.affiliation: Diagnostics Group, PATH, Seattle, Washington, USA.
authors.forename: Lindsay
authors.initials: L
authors.lastname: Yokobe
authors.affiliation: Diagnostics Group, PATH, Seattle, Washington, USA.
authors.forename: Gonzalo J
authors.initials: GJ
authors.lastname: Domingo
authors.affiliation: Diagnostics Group, PATH, Seattle, Washington, USA.
authors.forename: Tala
authors.initials: T
authors.lastname: de los Santos
authors.affiliation: Laboratory of Parasitic Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, USA tnutman@niaid.nih.gov.
authors.forename: Thomas B
authors.initials: TB
authors.lastname: Nutman
mesh_terms: D000349:Africa; D000818:Animals; D000909:Antibodies, Helminth / Q000097:blood; D000947:Antigens, Helminth / Q000276:immunology; D002846:Chromatography, Affinity / Q000379:methods; D003955:Diagnostic Tests, Routine / Q000379:methods*; D004605:Elephantiasis, Filarial / Q000175:diagnosis* / Q000453:epidemiology; D062665:Epidemiological Monitoring; D006801:Humans; D017181:Onchocerca volvulus / Q000302:isolation & purification*; D009855:Onchocerciasis / Q000175:diagnosis* / Q000453:epidemiology; D019095:Point-of-Care Systems; D011237:Predictive Value of Tests; D012680:Sensitivity and Specificity; D013997:Time Factors; D014958:Wuchereria bancrofti / Q000302:isolation & purification*
chemical_list: D000909:Antibodies, Helminth; D000947:Antigens, Helminth