title: Highly accurate antibody assays for early and rapid detection of tuberculosis in African and Asian elephants.
abstract: Tuberculosis (TB) in elephants is a reemerging zoonotic disease caused primarily by Mycobacterium tuberculosis. Current methods for screening and diagnosis rely on trunk wash culture, which has serious limitations due to low test sensitivity, slow turnaround time, and variable sample quality. Innovative and more efficient diagnostic tools are urgently needed. We describe three novel serologic techniques, the ElephantTB Stat-Pak kit, multiantigen print immunoassay, and dual-path platform VetTB test, for rapid antibody detection in elephants. The study was performed with serum samples from 236 captive African and Asian elephants from 53 different locations in the United States and Europe. The elephants were divided into three groups based on disease status and history of exposure: (i) 26 animals with culture-confirmed TB due to M. tuberculosis or Mycobacterium bovis, (ii) 63 exposed elephants from known-infected herds that had never produced a culture-positive result from trunk wash samples, and (iii) 147 elephants without clinical symptoms suggestive of TB, with consistently negative trunk wash culture results, and with no history of potential exposure to TB in the past 5 years. Elephants with culture-confirmed TB and a proportion of exposed but trunk wash culture-negative elephants produced robust antibody responses to multiple antigens of M. tuberculosis, with seroconversions detectable years before TB-positive cultures were obtained from trunk wash specimens. ESAT-6 and CFP10 proteins were immunodominant antigens recognized by elephant antibodies during disease. The serologic assays demonstrated 100% sensitivity and 95 to 100% specificity. Rapid and accurate antibody tests to identify infected elephants will likely allow earlier and more efficient treatment, thus limiting transmission of infection to other susceptible animals and to humans.
authors.affiliation: Chembio Diagnostic Systems, Inc, Medford, New York 11763, USA.
authors.forename: Rena
authors.initials: R
authors.lastname: Greenwald
authors.forename: Olena
authors.initials: O
authors.lastname: Lyashchenko
authors.forename: Javan
authors.initials: J
authors.lastname: Esfandiari
authors.forename: Michele
authors.initials: M
authors.lastname: Miller
authors.forename: Susan
authors.initials: S
authors.lastname: Mikota
authors.forename: John H
authors.initials: JH
authors.lastname: Olsen
authors.forename: Ray
authors.initials: R
authors.lastname: Ball
authors.forename: Genevieve
authors.initials: G
authors.lastname: Dumonceaux
authors.forename: Dennis
authors.initials: D
authors.lastname: Schmitt
authors.forename: Torsten
authors.initials: T
authors.lastname: Moller
authors.forename: Janet B
authors.initials: JB
authors.lastname: Payeur
authors.forename: Beth
authors.initials: B
authors.lastname: Harris
authors.forename: Denise
authors.initials: D
authors.lastname: Sofranko
authors.forename: W Ray
authors.initials: WR
authors.lastname: Waters
authors.forename: Konstantin P
authors.initials: KP
authors.lastname: Lyashchenko
mesh_terms: D000818:Animals; D000907:Antibodies, Bacterial / Q000097:blood*; D000942:Antigens, Bacterial / Q000276:immunology; D001426:Bacterial Proteins / Q000276:immunology; D004606:Elephants; D005060:Europe; D007118:Immunoassay / Q000379:methods; D009163:Mycobacterium bovis / Q000302:isolation & purification; D009169:Mycobacterium tuberculosis / Q000302:isolation & purification; D012680:Sensitivity and Specificity; D014376:Tuberculosis / Q000662:veterinary*; D014481:United States
chemical_list: D000907:Antibodies, Bacterial; D000942:Antigens, Bacterial; D001426:Bacterial Proteins; C117940:CFP-10 protein, Mycobacterium tuberculosis; C093276:ESAT-6 protein, Mycobacterium tuberculosis