Sensitivity and specificity for African horse sickness antibodies detection using monovalent and polyvalent vaccine antigen-based dot blotting

Research (Published online: 05-12-2022)

1. Sensitivity and specificity for African horse sickness antibodies detection using monovalent and polyvalent vaccine antigen-based dot blotting

Machimaporn Taesuji, Khate Rattanamas, Usakorn Kulthonggate, Thanongsak Mamom, and Sakchai Ruenphet

Veterinary World, 15(12): 2760-2763

Machimaporn Taesuji: Master of Science Program in Animal Biotechnology, Faculty of Veterinary Medicine, Mahanakorn University of Technology, Bangkok, Thailand; Clinic for Horse, Faculty of Veterinary Medicine, Mahanakorn University of Technology, Bangkok, Thailand.

Khate Rattanamas: Master of Science Program in Animal Biotechnology, Faculty of Veterinary Medicine, Mahanakorn University of Technology, Bangkok, Thailand.

Usakorn Kulthonggate: Clinic for Horse, Faculty of Veterinary Medicine, Mahanakorn University of Technology, Bangkok, Thailand.

Thanongsak Mamom: Master of Science Program in Animal Biotechnology, Faculty of Veterinary Medicine, Mahanakorn University of Technology, Bangkok, Thailand; Department of Pathology, Faculty of Veterinary Medicine, Mahanakorn University of Technology, Bangkok, Thailand.

Sakchai Ruenphet: Master of Science Program in Animal Biotechnology, Faculty of Veterinary Medicine, Mahanakorn University of Technology, Bangkok, Thailand; Department of Immunology and Virology, Faculty of Veterinary Medicine, Mahanakorn University of Technology, Bangkok, Thailand.

doi: www.doi.org/10.14202/vetworld.2022.2760-2763

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Article history: Received: 11-07-2022, Accepted: 26-10-2022, Published online: 05-12-2022

Corresponding author: Sakchai Ruenphet

E-mail: rsakchai@hotmail.com

Citation: Taesuji M, Rattanamas K, Kulthonggate U, Mamom T, and Ruenphet S (2022) Sensitivity and specificity for African horse sickness antibodies detection using monovalent and polyvalent vaccine antigen-based dot blotting, Veterinary World, 15(12): 2760–2763.

Abstract

Background and Aim: The immune responses of animals infected with African horse sickness (AHS) virus are determined by enzyme-linked immunosorbent assay (ELISA), complement fixation, and virus neutralization test. During the outbreaks of AHS in Thailand, the immune response after vaccination has been monitored using commercial test kits such as blocking ELISA, which are expensive imported products unavailable commercially in Thailand. This study aimed to assess the sensitivity and specificity of anti-AHS virus antibodies using dot blotting based on monovalent and polyvalent strains of live attenuated AHS vaccine.

Materials and Methods: A total of 186 horse sera, namely, 93 AHS-unvaccinated samples and 93 AHS-vaccinated samples, were used in this study. All sera underwent antibodies detection using commercial blocking ELISA and in-house dot blotting based on monovalent and polyvalent strains of live attenuated AHS vaccine. The numbers of true positive, false positive, true negative, and false negative results in the dot blotting were compared with those in blocking ELISA and the sensitivity and specificity of dot blotting were assessed.

Results: For the monovalent antigen, there were 78, 19, 74, and 15 true positive, false positive, true negative, and false negative results, respectively, while for the polyvalent antigen, the corresponding numbers were 84, 34, 58, and 9. Meanwhile, the diagnostic sensitivity and specificity for monovalent antigen were 83.87% and 79.57%, respectively, but 90.32% and 62.37% for polyvalent antigen.

Conclusion: Dot blotting for AHS antibodies detection using vaccine antigen showed high sensitivity and rather a high specificity compared with the findings with the commercial ELISA test kit. In countries where commercial ELISA test kits are not available and when the size of a serum sample is small, dot blotting could become a good alternative test given its advantages, including its simplicity, rapidity, and convenience. To the best of our knowledge, these findings are the first report on the use of dot blotting for detecting AHS antibodies in horses. In conclusion, monovalent antigen-based dot blotting could be used as a reliable alternative serodiagnostic test for monitoring AHS humoral immune response, especially in vaccinated horses.

Keywords: African horse sickness, blocking enzyme-linked immunosorbent assay, dot blotting, sensitivity, specificity.