A network approach for provisional assay recognition of a Hendra virus antibody ELISA: test validation with low sample numbers from infected horses

• Published in: Journal of veterinary diagnostic investigation Vol. 30; no. 3; pp. 362 - 369
• Main Authors: Colling, Axel, Lunt, Ross, Bergfeld, Jemma, McNabb, Leanne, Halpin, Kim, Juzva, Susan, Newberry, Kim, Morrissy, Chris, Loomes, Cameron, Warner, Simone, Diallo, Ibrahim, Kirkland, Peter, Broder, Christopher C., Carlile, Gemma, Loh, Mai Hlaing, Waugh, Caryll, Wright, Lynda, Watson, James, Eagles, Debbie, Zuelke, Kurt, McCullough, Sam, Daniels, Peter
• Format: Journal Article
• Language: English
• Published: Los Angeles, CA SAGE Publications 01.05.2018
• Subjects: Animals; Antibodies, Viral - blood; Enzyme-Linked Immunosorbent Assay - veterinary; Full Scientific Reports; Hendra Virus - immunology; Horse Diseases - virology; Horses; Sensitivity and Specificity; specificity; sensitivity; Hendra virus serology; validation; horses; network
• ISSN: 1040-6387; 1943-4936
• DOI: 10.1177/1040638718760102

Obtaining statistically sound numbers of sera from Hendra virus (HeV)-infected horses is problematic because affected individuals usually die or are euthanized before developing a serum antibody response. As a consequence, test validation becomes a challenge. Our approach is an extension of OIE principles for provisional recognition and included 7 validation panels tested across multiple laboratories that provided estimates for test performance characteristics. At a 0.4 S/P cutoff, 16 of 19 sera from HeV-infected horses gave positive results in the HeV soluble G, indirect ELISA (HeVsG iELISA; DSe 84.2% [95% CI: 60.4–96.6%]); 463 of 477 non-infected horse sera tested negative (DSp 97.1% [95% CI: 95.1–98.4%]). The HeVsG iELISA eliminated almost all false-positive results from the previously used HeV iELISA, with marginally decreased relative sensitivity. Assay robustness was evaluated in inter-laboratory and proficiency testing panels. The HeVsG iELISA is considered to be fit for purpose for serosurveillance and international movement of horses when virus neutralization is used for follow-up testing of positive or inconclusive serum samples.