title: Tuberculosis in elephants: antibody responses to defined antigens of Mycobacterium tuberculosis, potential for early diagnosis, and monitoring of treatment.
abstract: Tuberculosis (TB) in elephants is a re-emerging zoonotic disease caused primarily by Mycobacterium tuberculosis. Current diagnosis relies on trunk wash culture, the only officially recognized test, which has serious limitations. Innovative and efficient diagnostic methods are urgently needed. Rapid identification of infected animals is a crucial prerequisite for more effective control of TB, as early diagnosis allows timely initiation of chemotherapy. Serology has diagnostic potential, although key antigens have not been identified and optimal immunoassay formats are not established. To characterize the humoral responses in elephant TB, we tested 143 serum samples collected from 15 elephants over time. These included 48 samples from five culture-confirmed TB cases, of which four were in Asian elephants infected with M. tuberculosis and one was in an African elephant with Mycobacterium bovis. Multiantigen print immunoassay (MAPIA) employing a panel of 12 defined antigens was used to identify serologic correlates of active disease. ESAT-6 was the immunodominant antigen recognized in elephant TB. Serum immunoglobulin G antibodies to ESAT-6 and other proteins were detected up to 3.5 years prior to culture of M. tuberculosis from trunk washes. Antibody levels to certain antigens gradually decreased in response to antitubercular therapy, suggesting the possibility of treatment monitoring. In addition to MAPIA, serum samples were evaluated with a recently developed rapid test (RT) based on lateral flow technology (ElephantTB STAT-PAK). Similarly to MAPIA, infected elephants were identified using the RT up to 4 years prior to positive culture. These findings demonstrate the potential for TB surveillance and treatment monitoring using the RT and MAPIA, respectively.
authors.affiliation: Chembio Diagnostic Systems, Inc., 3661 Horseblock Road, Medford, New York 11763, USA. klyashchenko@chembio.com
authors.forename: Konstantin P
authors.initials: KP
authors.lastname: Lyashchenko
authors.forename: Rena
authors.initials: R
authors.lastname: Greenwald
authors.forename: Javan
authors.initials: J
authors.lastname: Esfandiari
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: Freeland
authors.initials: F
authors.lastname: Dunker
authors.forename: Carol
authors.initials: C
authors.lastname: Buckley
authors.forename: Michael
authors.initials: M
authors.lastname: Richard
authors.forename: Suzan
authors.initials: S
authors.lastname: Murray
authors.forename: Janet B
authors.initials: JB
authors.lastname: Payeur
authors.forename: Peter
authors.initials: P
authors.lastname: Andersen
authors.forename: John M
authors.initials: JM
authors.lastname: Pollock
authors.forename: Susan
authors.initials: S
authors.lastname: Mikota
authors.forename: Michele
authors.initials: M
authors.lastname: Miller
authors.forename: Denise
authors.initials: D
authors.lastname: Sofranko
authors.forename: W Ray
authors.initials: WR
authors.lastname: Waters
mesh_terms: D000818:Animals; D000907:Antibodies, Bacterial / Q000097:blood; D000942:Antigens, Bacterial / Q000276:immunology; D001426:Bacterial Proteins; D004606:Elephants; D005260:Female; D007118:Immunoassay; D007074:Immunoglobulin G / Q000097:blood; D009163:Mycobacterium bovis / Q000276:immunology; D009169:Mycobacterium tuberculosis / Q000276:immunology*; D011933:Reagent Kits, Diagnostic / Q000662:veterinary; D014376:Tuberculosis / Q000175:diagnosis / Q000188:drug therapy / Q000662:veterinary*
chemical_list: D000907:Antibodies, Bacterial; D000942:Antigens, Bacterial; D001426:Bacterial Proteins; C093276:ESAT-6 protein, Mycobacterium tuberculosis; D007074:Immunoglobulin G; D011933:Reagent Kits, Diagnostic