Filipino farmers who raise pigs on their farms regard Asian swine fever (ASF) as one of their greatest concerns. This is because ASF is not a typical swine fever. A highly contagious hemorrhagic fever caused by the ASF virus, it affects both domestic and wild pigs regardless of age.
Since its emergence in the Philippines in 2019, the disease has drastically diminished the local hog population, with figures plummeting from 12.7 million heads in 2019 to 8.75 million in 2024-2025. This substantial reduction in hog supply has caused pork prices to nearly double—from ₱224.19 per kilogram to ₱450.00 per kilogram.
Dr. Synan S. Baguio from the Philippine Council for Agriculture, Aquatic and Natural Resources Research and Development (PCAARRD) states that variations in the prices of raw materials and animal feed have a significant effect on the total cost of pork production, which in turn affects market pork prices.
The disease is referred to by this name due to its origins in Africa, where it was initially identified in the 1920s. The earliest outbreaks of ASF were reported in China, the largest pork producer globally, in August 2018.
ASF rapidly disseminated to all provinces within that nation. Subsequently, ASF crossed into Vietnam, Laos, Cambodia, Indonesia, Myanmar, Mongolia, North Korea, and the Philippines. Additionally, outbreaks have been documented in various regions of Europe, South America, and the Caribbean.
“ASF is a contagious viral disease that affects pigs of all ages,” the UN Food and Agriculture Organization (FAO) explains in its manual, African Swine Fever: Detection and Diagnosis. “It can appear in a variety of forms ranging from peracute, acute, subacute, to chronic and apparent. It is most often recognized in the acute form with an associated lethality of up to 100%.”
A report from the Organization for Economic Cooperation and Development said that an average Filipino consumes about 14.2 kilograms of pork (2 kilograms more than the world’s average pork consumption).
ASF has impacted 76 of the country’s 82 provinces since 2019, with 6 provinces having active cases as of 11 July 2025, which consequently, the Department of Agriculture (DA) has called for an additional production of two million hogs annually to meet its recovery targets.
“African swine fever is a severe threat to pig production systems,” the FAO publication states. “It not only threatens food security and challenges the livelihoods of pig producers and other actors in the supply chain but may also have major consequences on international trade as a result of trade restrictions.”
Dr. Jaime A. Sison, a veterinarian who specializes in the area of pig and chicken and a regular columnist for a monthly agriculture publication, said the symptoms of ASF include high fever, decreased appetite, skin lesions and diarrhea.
“The tricky thing about diagnosing a potential case of ASF is that it can look a lot like other more common diseases,” said Dr.
Sison. “(Symptoms of ASF) are just like those of the common porcine epidemic diarrhea virus or classical swine fever.”
Dr. Sison urged swine farmers to report any suspected outbreaks to their local animal health officers, as it is much easier to test a false positive than to contain an outbreak that’s festered for days.
“ASF’s real calling card is its mortality rate: it claims almost all infected animals with 7-10 days of showing symptoms, and some drop dead much earlier – without showing any outward signs of illness,” Dr. Sison said.
The United Nations food agency says ASF virus is shed in saliva, tears, nasal secretions, urine, feces, and secretions from the genital tract. “Blood, in particular, contains large amounts of virus,” FAO claims. “Pigs can therefore become infected by contact with many different infected sources, mainly infected pigs, pork, and other pig-derived products.”
ASF can also be spread via pork and pork-derived products. The state of the pork, whether raw, frozen, dried, or undercooked, is irrelevant, as the virus can persist for an extended period. It remains infectious for up to 15 weeks in chilled meat (and likely for a longer duration in frozen meat), and for several months in bone marrow or cured hams and sausages, unless they have been subjected to high-temperature cooking or smoking.
The World Organization for Animal Health (OIE) based in the United Kingdom calls ASF as “transboundary animal disease.” “Transmission can also occur via contaminated feed and fomites (non-living objects) such as shoes, clothes, vehicles, knives, equipment, etc.,” OIE explains. “These contaminated materials can be transported over long distances by vehicles and people.”
But the good thing is: “Although highly lethal, ASF is less infectious than some other transboundary animal diseases such as foot-and-mouth disease,” the FAO claims. In Africa, some indigenous pigs have been reported to have developed some degree of tolerance to ASF.
But unlike most transboundary animal diseases, ASF has no vaccines or drugs available to prevent or treat it. “It is particularly important that ASF-free areas are maintained as such,” FAO suggests.
An ounce of prevention is better than a pound of cure, so goes a saying. “Prevention starts with stringent measures at the borders and raising awareness among all stakeholders involved,” FAO recommends. “Early detection, early diagnosis, early response, and good communication are critical in minimizing the spread of the disease after incursion.”
In a bid to reinforce its commitment to combat the threat of ASF and secure the future of the country’s swine industry, the Department of Science and Technology (DOST) recently unveiled three locally developed technologies for early detection, rapid response, and long-term prevention of the disease.
Because ASF signs resemble those of Classical Swine Fever, laboratory testing is essential for accurate diagnosis. The DOST’s Industrial Technology Development Institute developed two technologies that use a rapid, accurate, and real-time Polymerase Chain Reaction (PCR) protocol applicable for point-of-need detection of ASFV. PCR is a laboratory technique used for amplifying multiple copies of a target DNA segment from a sample. It involves single-stranded DNA fragments called primers that complement the target DNA segment for multiple gene amplification.
These two developed technologies to detect ASFV are “TUSLOB® Rapid DNA Extraction Kit” and “VIPtec® African Swine Fever Virus (ASFV) Real-time PCR Detection Kit.”
These two kits provide rapid, accurate, and high-quality DNA extraction from the blood samples of potentially ASF-infected pigs. Designed to be user-friendly and optimized for locally circulating ASF strains, the tools support on-site testing in veterinary and agricultural settings, aiding in the control of ASF outbreaks and the reduction of economic losses.
The third technology is the first Filipino-made “Mobile Biocontainment Laboratory (MBL)” developed by BioAssets Corporation. MBL was intended to support rapid response to potential outbreaks and improve capacity building and disease surveillance that would enable farmers and veterinarians to craft mitigation strategies, preventive and control measures at the point-of-need.
“It’s very important to show that Filipinos are capable of developing technologies that can help address our food-related problems,” said Science Secretary Renato Solidum, Jr.
To address temporary supply shortages, pork imports rose by 25.9% in the first quarter of 2025, with 53.2% of these imports consisting of pork, as reported by the Bureau of Animal Industry (BAI).
In light of the ASF incident, Secretary Solidum proposed the establishment of the Virology and Vaccine Institute of the Philippines (VIP). This initiative aims not only to combat ASF but also to tackle other emerging diseases and viral threats.
“With VIP, we can boost our country’s capacity to anticipate, detect, and respond to emerging and re-emerging viral threats—not just for animals, but for plants and humans as well,” explained Solidum. “Why do we need to establish one in the Philippines and why not use other solutions from other countries? Simply because, the strains that we may have may be different from the strains that other vaccines developed in other countries are addressing.”
Meanwhile, the Department of Health (DOH) assured consumers that pork infected with ASF does not pose a risk on human health.
“We want to allay the fears of the public by saying that, as long as pork is bought from reliable sources and it is cooked thoroughly, pork is safe to eat,” said Dr. Francisco Duque III at the time when he was still the health secretary.
The agriculture department also stated that as long as the hogs passed through the proper process of slaughtering and preparation, the public should not fear eating pork.
FAO says ASF virus survives well under most environmental conditions; 2-3 months in carcasses and in sheds. It can even survive for many months in meat. “The ASF virus resists the freezing process but is inactivated by high temperature,” FAO points out. High temperature means 30 minutes at 70 degrees Centigrade.
Dr. Ann Garvey, an American veterinarian from the Iowa State Public Health, says ASF affects only pigs and not human beings and other livestock. “African swine fever is a viral disease impacting only pigs, not people, so it is not a public health threat, nor it is a food-safety concern,” she explains. —
