Last Updated on 2025 年 10 月 27 日 by 総合編集組
Unraveling African Swine Fever: A Global Crisis Threatening Economies in 2025
Introduction African Swine Fever (ASF) is not a human health threat, but its devastating impact on the global pork industry, food security, and economies cannot be overstated. As of October 2025, ASF has spread to 74 countries, resulting in over 2.25 million pigs dead or culled and economic losses in the billions, including an estimated $111 billion in China alone. Taiwan’s first domestic outbreak in October 2025 has heightened global concerns, prompting stringent measures like nationwide transport bans. This summary explores ASF’s virology, transmission, economic fallout, and actionable prevention strategies, offering insights for consumers, farmers, and policymakers.
What is ASF? A Lethal Virus for Pigs ASF is a highly contagious viral disease affecting domestic and wild pigs, with mortality rates approaching 100% in acute cases. Caused by the African Swine Fever Virus (ASFV), a complex double-stranded DNA virus from the Asfarviridae family, ASFV encodes 151–167 open reading frames, making it unique in virology. Symptoms include high fever, loss of appetite, skin hemorrhages, and sudden death, often mimicking classical swine fever (CSF). However, ASFV’s hemadsorption trait distinguishes it, requiring lab tests like PCR or ELISA for accurate diagnosis. Crucially, ASFV is not zoonotic, meaning it poses no direct risk to humans, and properly cooked pork is safe for consumption, as confirmed by the USDA, WOAH, and CDC.
ASFV’s Remarkable Environmental Resilience The virus’s ability to survive in diverse conditions makes it a formidable foe. ASFV can remain infectious for years at -70°C, up to 105 weeks in frozen meat at -20°C, and 155 days in refrigerated meat at 4°C. In soil, it persists for up to 280 days, and in contaminated bone marrow, over 180 days. While long-cured meats like Iberian ham (300–399 days) inactivate the virus, improperly processed pork products are a major transmission risk. This resilience underscores the need for rigorous biosecurity and thorough disinfection in affected areas.
Transmission Pathways: A Complex Web ASF spreads through multiple channels, complicating control efforts:
- Oral Transmission: Feeding pigs contaminated swill or kitchen scraps is a primary infection route, especially in small-scale farms where swill may not be heated to the required 90°C for 60 minutes.
- Wildlife Reservoirs: In Africa, warthogs and soft ticks (Ornithodoros spp.) form a sylvatic cycle, while wild boars in Europe and Asia act as disease reservoirs, spreading ASFV to domestic pigs.
- Human-Driven Spread: Illegal transport of contaminated pork products across borders is a key driver of long-distance transmission. For instance, the 2007 Georgia outbreak stemmed from contaminated ship waste.
- Environmental and Aerosol Spread: ASFV can spread via contaminated vehicles, clothing, or aerosols over short distances, necessitating strict farm biosecurity.
Economic and Social Devastation ASF’s economic toll is staggering. China’s 2018–2021 outbreak slashed pig populations by 40%, costing $111 billion and spiking pork prices, which rippled to inflate beef and poultry costs. Vietnam lost over 6 million pigs (20% of its herd) in 2019, with losses up to $4.4 billion. Globally, pork exports dropped 15%, and production fell over 4%. Small-scale farmers face existential threats, as mass culling—often the only control measure—wipes out livelihoods, sparking ethical debates. In regions like China, where pork accounts for 60% of protein intake, ASF threatens food security and social stability, aligning with the “One Health” framework that links animal, environmental, and human impacts.
Taiwan’s 2025 Outbreak: A Wake-Up Call Taiwan, long vigilant against ASF due to its proximity to China, faced its first domestic outbreak in October 2025 at a Taichung farm. Authorities culled 195 pigs, established a 3-km control zone, and imposed a nationwide transport and slaughter ban. Suspected to originate from illegal pork imports, the outbreak prompted “wartime-level” border checks, including 100% X-ray screening of luggage from high-risk regions. Taiwan’s three-tier defense—border control, farm biosecurity, and early warning systems—highlights the urgency of proactive measures to protect its pork industry.
Consumer Guidelines: Safe Pork Consumption While ASF poses no human health risk, consumers should follow food safety protocols:
- Cook pork to an internal temperature of 70°C for 30 minutes to inactivate ASFV.
- Prevent cross-contamination by separating raw and cooked foods, using different utensils, and washing hands thoroughly.
- Purchase pork from reputable, inspected sources to minimize risks from unregulated products.
Swill feeding, a major ASF transmission risk, must be heated to 90°C for 60 minutes to ensure virus inactivation, a standard small farms often fail to meet due to inadequate equipment.
Social Media and Misinformation ASF outbreaks often trigger public panic fueled by sensational media headlines like “Deadly Swine Fever Outbreak.” Studies show that consumers with limited prior knowledge of ASF’s non-zoonotic nature tend to avoid pork purchases, even when informed of its safety. On platforms like China’s Weibo, discussions split between ordinary users worried about pork prices and safety, experts advocating for prevention, and media amplifying fear. Effective crisis communication—proactive, transparent, and emphasizing ASF’s safety for humans—is critical to countering misinformation and stabilizing markets.
Global Control Efforts: Biosecurity and Vaccine Challenges With no commercial vaccine available, biosecurity remains the cornerstone of ASF prevention:
- Farm Measures: Double fencing to block wild boars, restricted personnel access, and thorough disinfection of vehicles and equipment.
- Policy Frameworks: Programs like the USDA’s Secure Pork Supply ensure uninfected farms can operate during outbreaks with stringent protocols. Vaccine development faces hurdles due to ASFV’s genetic complexity. Live attenuated vaccines (LAVs) risk reverting to virulence, while subunit vaccines, like those targeting CD2v protein, show promise but lack broad protection against diverse strains. The “DIVA” strategy (Differentiating Infected from Vaccinated Animals) is essential for trade compliance, requiring ongoing research and independent monitoring.
Conclusion: A Call for Global Action ASF’s global spread demands coordinated action. Governments must enforce strict border controls, support vaccine research, and provide economic aid to farmers. Consumers should trust official safety guidelines and avoid illegal pork imports, which could trigger catastrophic outbreaks. Taiwan’s 2025 response exemplifies the need for swift, decisive action. By combining biosecurity, public education, and scientific innovation, we can mitigate ASF’s devastating impact and safeguard global food security.
