Competitive ELISA-p30Ab

The ELISA kit is conducted using p30 protein antibodies as the target. The p30 protein is located in the inner membrane of the virus, whereas the p72 protein is found in the outer membrane. Consequently, the p30 protein can be detected at an earlier stage—before the virus begins assembling within the host—making it a useful early marker of infection.

 

Regarding the diagnostic window period, antibody levels typically rise rapidly within one to two weeks after infection, whereas antigen levels drop sharply after the second week. In cases of African swine fever virus (ASFV) outbreaks on pig farms, the number of abnormal pig deaths tends to increase exponentially around two weeks post-infection. At this stage, antibody levels remain at a high peak, while antigen sensitivity decreases.

 

Performance validation

The detection capability of the Sentinel ASFV Ab ELISA was evaluated by using IPT to perform endpoint dilutions, generating different titers of African swine fever (ASF) antibodies, and comparing the consistency of the results with those of IPT.
 

Among the 368 tested samples, IPT (the gold standard) identified 297 as positive and 71 as negative. The Sentinel ASFV Ab ELISA produced 33 false-negative results but no false positives. Data analysis showed that the sensitivity and specificity of the Sentinel ASFV Ab ELISA were 88.9% (264/297) and 100% (71/71), respectively. These findings align with the clinical manifestations of ASF.
 

Additionally, among 380 field samples, 371 ASF-positive and 9 ASF-negative serum samples were confirmed by PCR nucleic acid testing. A comparative analysis between the Sentinel ASFV Ab ELISA and IPT detection methods demonstrated an almost perfect agreement (kappa = 0.93). Notably, the Sentinel ASFV Ab ELISA yielded no false-positive results, maintaining a specificity of 100%.
 

After compiling and analyzing the data, the validation results from both the challenge test and field sample comparisons with IPT and cELISA confirm that the Sentinel ASFV Ab ELISA is a suitable and reliable tool for detecting ASFV antibodies. The Sentinel ASFV Ab ELISA reagent can serve as an effective and dependable monitoring tool for ASF surveillance.