blog about South Korea Tests Nine African Swine Fever PCR Kits for Food Waste Safety

The shadow of African Swine Fever (ASF) is spreading across the global pork industry at an unprecedented rate. This highly contagious disease, caused by the African Swine Fever Virus (ASFV), not only devastates swine populations but also inflicts massive economic losses on livestock sectors worldwide due to its near-100% mortality rate and rapid transmission. ASFV, a complex enveloped double-stranded DNA virus, has been classified into six major genotypes through advanced genomic sequencing, with the relatively conserved p72 gene serving as a key marker for differentiation.

ASF’s impact extends far beyond farms. Research indicates that ASFV can spread through undercooked or contaminated pork products, particularly via food waste recycled as feed, posing a persistent risk of secondary infections. In response, countries like South Korea have implemented strict measures, including bans on using food waste in animal feed. Early surveillance of ASFV in food waste streams has thus become a critical priority.

Despite experimental vaccine candidates targeting specific gene deletions, no commercially viable ASF vaccine exists. This absence underscores the importance of highly sensitive and specific diagnostic tools as the foundation of ASF control strategies.

The World Organisation for Animal Health (WOAH) recommends three PCR-based diagnostic methods—one conventional and two real-time PCR assays—for high-throughput screening of suspected ASFV samples. Since the release of WOAH standards, advanced techniques like ELISA, LAMP, multiplex PCR, and ultra-sensitive real-time PCR have emerged. However, many remain confined to research settings, with their real-world performance—especially of commercial kits—requiring rigorous evaluation by end-users and regulators.

To address this gap, researchers systematically evaluated nine MAFRA-approved ASFV real-time PCR kits in South Korea. Using 20 food waste samples and synthetic ASFV-positive controls, the study assessed critical performance metrics: specificity, sensitivity, cost per reaction, and processing time. Results were benchmarked against prior data to guide the selection of optimal diagnostic tools.

Key methodological details:

• Sample selection: 20 food waste samples randomly selected from 5,581 ASFV-negative specimens collected between 2020–2022.
• Safety protocols: Synthetic ASFV sequences (HBNH-2019 strain) and reference viruses (PCV2, PPV, PrV) were used to eliminate biohazard risks.
• DNA extraction: Performed using QIAamp® DNA mini kits after homogenization of 1g samples.

Under stringent conditions (1000 RFU, kit-specific Cq thresholds), most kits detected ASFV at concentrations below 1 fg/μL. Three kits from Median Diagnostics, Ahram Biosystems, and MiCo Biosystems achieved exceptional sensitivity at 100 ag/μL. When applying a unified Cq threshold (<35), four kits maintained detection at 1 fg/μL, with five still functional at 10 fg/μL under elevated RFU (2500) conditions.

Notable findings:

• Cost efficiency: Six kits maintained costs below 10,000 KRW per reaction.
• Speed: Three kits (Ahram Biosystems, MiCo BioMed, Kogene Biotech) completed analyses in 50–70 minutes—1 hour faster than WOAH protocols.
• Validation: Three top-performing kits (VDx®, Palm PCR™, PowerChek™) showed consistent results across multiple analysts.

This first comprehensive evaluation of MAFRA-approved ASFV kits in South Korea identifies optimal tools for food waste surveillance. The selected kits combine high sensitivity (100 ag/μL), affordability (<10,000 KRW/reaction), and rapid processing (<70 minutes)—critical attributes for large-scale monitoring programs.

Study constraints include the absence of field samples from infected animals due to biosafety concerns, and exclusive focus on food waste matrices. Future research should validate these findings with diverse sample types, including clinical specimens from outbreaks.