Sampling and Laboratory Capacity Challenges in African Swine Fever Containment

A recent study highlights critical weaknesses in sampling procedures and laboratory infrastructure that could hinder efforts to detect and control African swine fever (ASF) outbreaks in the United States. The research, published in Preventive Veterinary Medicine, emphasizes that the effectiveness of outbreak management heavily depends on efficient testing strategies, especially in regions with dense pig populations.

ASFV, a highly contagious virus affecting pigs, can cause mortality rates of up to 100%. One of its particularly alarming features is that infected pigs often die without showing any symptoms, facilitating undetected spread of the virus. The potential economic impact of an ASF outbreak in the U.S. has been estimated at around $80 billion, underscoring the importance of preparedness.

The study conducted by North Carolina State University used a model called PigSpread to simulate ASFV transmission scenarios. It found that rapid and extensive sampling is vital for containment. During an outbreak, health officials must visit farms to collect blood and oral samples, and to prevent cross-contamination, samples from different farms must be collected at least 72 hours apart.

Simulations revealed that managing an outbreak could require thousands of samples from numerous pig barns. For example, in median outbreak scenarios, over 3,000 barns might need sampling, requiring at least 136 to 367 personnel to collect 31 samples per barn. In larger epidemic scenarios, the personnel needed could surpass 3,000, illustrating significant logistical challenges.

Laboratory processing capacity was another major concern. The current model assumes labs can handle up to 1,000 samples daily, but delays in processing—median delays could reach 92 days, with worst-case delays extending to five years—pose a serious threat to timely response. To address this, pooling samples from the same barn into a single test is suggested to reduce laboratory strain and speed up results.

The study also suggests that decreasing sample collection downtime from 72 to 24 hours and incorporating oral samples alongside blood tests might improve surveillance efficiency. However, further research is needed to confirm the effectiveness of oral sampling.

Overall, the research underscores that current sampling strategies require significant improvements to ensure quick and effective ASF detection. Strengthening both field sampling logistics and laboratory processing capacity is essential for early intervention and outbreak prevention.

Source: https://medicalxpress.com/news/2025-05-sampling-lab-capacity-weak-links.html