Taiwan’s ASF virus genetically close China, Vietnam strains

Analysis shows 99.95% similarity to a Chinese strain and 99.92% similarity to a Vietnamese strain.

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Taiwan’s ASF virus genetically close China, Vietnam strains

Farm porciNews Asia

Taiwan’s first confirmed case of African swine fever (ASF) case is genetically close to strains from China and Vietnam. However, its exact origin remains unclear.

On October 25, the Ministry of Agriculture (MOA) confirmed the outbreak at a pig farm in Taichung. Genetic analysis showed 99.95% similarity to a Chinese strain and 99.92% similarity to a Vietnamese strain.

To aid global monitoring, the ministry will submit the gene sequencing data to the World Organization for Animal Health (WOAH). Du Li-hwa, Director General of the Animal and Plant Health Inspection Agency (APHIA), said that while sharing the data is voluntary, it offers valuable insight into circulating strains.

Genetic clues and unresolved origins

Deng Ming-chung, Director General of the Veterinary Research Institute, explained that gene sequencing reveals only the virus’ genetic arrangement, which can evolve over time. Taiwan’s strain is over 99.5% similar to a recombinant strain from China, differing at just five positions out of 10,000.

Determining its exact origin depends on matching these differences with existing databases. Without a match, authorities can only estimate its likely source.

Containment measures and farm inspections

Enhanced biosecurity measures remain in effect. Inspections of more than 5200 farms have returned negative results, and second-round testing of 22 farms found no new infections.

However, on October 31, the Central Emergency Operation Center reported positive samples from three areas of the original Taichung pig farm where the ASF case was first detected. Military personnel assisted with cleaning, and the veterinary institute will conduct resampling after disinfection.

Authorities said there are no signs that ASF has spread beyond Taichung. Taiwan aims to return to zero cases and, after three months without new infections, regain ASF-free status.

Impacts and recovery timeline

Agriculture Minister Chen Junne-jih, who leads the Central Emergency Operation Center, stated that Taiwan will notify the WOAH and inform trade partners. Taiwan has suspended animal quarantine certificates for exports of live pigs, pig semen, and fresh pork products.

Ms Li-hwa added that if the outbreak is contained, Taiwan will submit a new self-declaration to regain ASF-free status.

Nationwide ban and supply management

To contain the virus, Taiwan has banned the transport and slaughter of pigs nationwide. The Ministry of Environment also banned the feeding and transport of kitchen waste to pig farms for at least 15 days. Such measures take into account the virus’s incubation period.

During this period, authorities will help farmers dispose of waste at designated facilities and offer fuel subsidies of USD 16.20-37.94 per trip, depending on herd size.

To prevent pork shortages, the MOA asked the Taiwan Frozen Food Processors Association to release existing stock to supermarkets and wholesale stores before the control measures are lifted. Taiwan’s 60,000-ton pork reserve can meet daily consumption of about 2300 tons for about a month.