# High-Accuracy Serodiagnosis of African Swine Fever Using P72 and P30-Based Lateral Flow Assays: A Validation Study with Field Samples in Thailand

## TL;DR

Researchers developed and validated rapid, low-cost tests to detect African Swine Fever antibodies in pigs, enabling quick on-site diagnosis to help control outbreaks.

## Contribution

The study introduces and validates P72- and P30-based lateral flow assays as highly accurate, field-deployable tools for African Swine Fever serodiagnosis.

## Key findings

- The P72-based lateral flow assay showed 100% sensitivity and specificity, matching the reference ELISA perfectly.
- The P30-based assay also performed well with 100% sensitivity and 98.7% specificity.
- The P54-based assay was unsuitable due to a high false positive rate.

## Abstract

African Swine Fever is a highly destructive disease devastating pig populations and causing severe economic damage globally. A major challenge in controlling its spread is the reliance on slow, expensive laboratory tests, which delay critical containment efforts. This study aimed to develop and validate simple, rapid “strip tests” (lateral flow assays) that could quickly detect antibodies to the virus at the farm. We created three test prototypes, each targeting a different viral protein (P72, P30, or P54), and tested them against 143 pig serum samples from Thailand. Our results showed that the rapid test targeting P72 was perfectly accurate, matching the complex laboratory test in every case. The P30 test was also found to be highly reliable, while the P54 test proved unsuitable due to a high number of false positive results. We conclude that the P72 and P30 rapid tests are excellent, low-cost tools for surveillance. Their value lies in allowing veterinarians and farmers to obtain accurate results “pen-side” in under 20 min to identify animals with past exposure, enabling immediate action to control outbreaks and protect the pork industry.

African Swine Fever (ASF) control is severely hampered by the reliance on slow, laboratory-bound diagnostics. While rapid, field-deployable lateral flow assays (LFAs) are urgently needed, the comparative performance of key single-antigen targets remains poorly characterized. This study aimed to develop and systematically evaluate the diagnostic performance of three in-house single-antigen LFAs targeting ASF virus P30, P54, and P72, using swine field samples from Thailand, including a panel of 143 quantitative polymerase chain reaction-negative swine serum samples. The performance of each LFA was compared against a commercial multi-antigen (P32/P62/P72) indirect ELISA, which served as the reference standard, classifying 64 samples as positive and 79 as negative. The P72-based LFA demonstrated perfect diagnostic performance (100% sensitivity, 100% specificity) and perfect agreement (κ = 1.0) with the enzyme-linked immunosorbent assay (ELISA). Similarly, the P30 LFA demonstrated high performance (100% sensitivity, 98.7% specificity) with ‘Almost Perfect’ agreement (κ = 0.9859). In contrast, the P54 LFA was unsuitable, achieving 100% sensitivity but unacceptably low specificity (88.6%) due to a high rate of false positives. Overall, the single-antigen P72 and P30 LFAs demonstrated excellent concordance with the multi-antigen ELISA, supporting their reliable for detecting antibodies against ASFV. Although these assays do not replace molecular methods for acute infection detection, they represent valuable complementary tools for serosurveillance.