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ARS Home » Pacific West Area » Pullman, Washington » Animal Disease Research » Research » Publications at this Location » Publication #413130
Research Project: Development of a Vaccine and Improved Diagnostics for Malignant Catarrhal Fever

Location: Animal Disease Research

Title: Evaluation of an in-house indirect immunoperoxidase test for detection of antibodies against African swine fever virus

Author
item WU, PING - Animal And Plant Health Inspection Service (APHIS)
item MCDANIEL, ARIC - Animal And Plant Health Inspection Service (APHIS)
item RODRÍGUEZ, YELITZA - Animal And Plant Health Inspection Service (APHIS)
item BLAKEMORE, LESLIE - Animal And Plant Health Inspection Service (APHIS)
item SCHUMANN, KATE - Animal And Plant Health Inspection Service (APHIS)
item Chung, Chungwon
item JIA, WEI - Animal And Plant Health Inspection Service (APHIS)

Submitted to: Journal of Veterinary Diagnostic Investigation
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/15/2024
Publication Date: 9/6/2024
Citation: Wu, P., Mcdaniel, A.J., Rodríguez, Y.Y., Blakemore, L., Schumann, K.R., Chung, C.J., Jia, W. 2024. Evaluation of an in-house indirect immunoperoxidase test for detection of antibodies against African swine fever virus. Journal of Veterinary Diagnostic Investigation. https://doi.org/10.1177/10406387241267883.
DOI: https://doi.org/10.1177/10406387241267883

Interpretive Summary: An in-house indirect immunoperoxidase test (IPT) for African Swine Fever (ASF) diagnosis was developed using MA-104 cells infected with ASF virus Georgia 2007/1 strain which is different from the reference IPT. The analytic sensitivity and specificity of the in-house IPT were found to be equivalent to the reference IPT. The diagnostic sensitivity and specificity of the in-house IPT were not statistically different from the reference IPT. However, with less tissue culture adaptation the in-house IPT can be potentially benefited by earlier detection of weak positive antibody. Field sample testing results by the in-house IPT and qPCR reflected the different statuses of ASF infection in a herd or an area. To ensure ASF diagnosis covers different field statuses of infection, it is essential to use both molecular and serological methods simultaneously.

Technical Abstract: African swine fever (ASF) is a high-consequence transboundary animal disease caused by African swine fever virus (ASFV). Given that vaccines are not widely available, ASFV detection, including by molecular and serologic assays, is paramount to efficacious control and mitigation of ASF. ASFV-specific antibodies can be detected as early as 7–10'd postinfection in infected animals and may persist for several months or longer. Accurate detection of ASFV-specific antibody is critical for the identification of chronically infected, subclinically infected, or recovered animals. ELISAs are commonly used for the rapid screening of large numbers of animals for ASFV antibodies. The World Organisation for Animal Health recommends that ELISA-positive results should be confirmed with a second serologic method, such as an indirect immunofluorescent assay, indirect immunoperoxidase test (IPT), or immunoblot test. Commercial kits are not available for those tests. We developed and validated an in-house IPT by using a currently circulating genotype II ASFV strain as antigen. The sensitivity and specificity of the in-house IPT are comparable to the reference IPT developed by an international ASFV reference laboratory and superior to a commercial blocking ELISA