Development of a highly sensitive point-of-care test for African swine fever that combines EZ-Fast DNA extraction with LAMP detection: Evaluation using naturally infected swine whole blood samples from Vietnam

BackgroundWhile early detection and early containment are key to controlling the African swine fever (ASF) pandemic, the lack of practical testing methods for use in the field are a major barrier to achieving this feat. ObjectivesTo describe the development of a rapid and sensitive point-of-care test (POCT) for ASF, and its evaluation using swine whole blood samples for field settings. MethodsIn total, 89 swine whole blood samples were collected from Vietnamese swine farms and were performed the POCT using a combination of crude DNA extraction and LAMP (loop-mediated isothermal amplification) amplification. ResultsThe POCT enabled crude DNA to be extracted from swine whole blood samples within 10 min at extremely low cost and with relative ease. The entire POCT required a maximum of 50 min from the beginning of DNA extraction to final judgment. Compared to a conventional real-time PCR detection, the POCT showed a 1 log reduction in detection sensitivity, but comparable diagnostic sensitivity of 100% (56/56) and diagnostic specificity of 100% (33/33). The POCT was quicker and easier to perform and did not require special equipment. ConclusionsThis POCT is expected to facilitate early diagnosis and containment of ASF invasion into both regions in which it is endemic and eradicated.

Automated summary

The lack of practical testing methods for African swine fever (ASF) has hindered early detection and early containment of the pandemic. In this study, a rapid and sensitive point-of-care test (POCT) was developed to detect ASF using swine whole blood samples. The POCT enabled crude DNA to be extracted from swine whole blood samples within 10 min at low cost and with ease. Compared to conventional real-time PCR detection, the POCT showed slightly lower sensitivity but comparable diagnostic accuracy. It is expected that this POCT will facilitate early diagnosis and containment of ASF.