African swine fever (ASF) is a major threat to pork production worldwide. Once the virus that causes the disease is passed to a member of the even-toed ungulate family (Suidae, or swine), to Sus Scrofa (Eurasian wild boar), or to related animals outside the genus including warthogs, rapid spread of the fever is common and likely, often targeting large numbers of susceptible animals, creating an outbreak that can quickly devastate domestic swine and feral swine populations across a large area.
"This virus is complex and much harder to deal with than simple viruses," says Dr. Waithaka Mwangi, Associate Professor at the Kansas State University College of Veterinary Medicine and an animal disease specialist. "Some isolates, such as the currently causing outbreaks in China, are highly virulent, and as such isolates cause 100-percent mortality. The virulent isolates could be considered the Ebola of pigs."
The United States Department of Agriculture-Animal and Plant Health Inspection Service (USDA-APHIS) recognizes the risks of ASF worldwide and acknowledges the recent dangers of incidents including the spread of the virus, which has affected swine from Africa to China and Western Europe. U.S. animal health officials say an outbreak in the U.S. could halt all pig and hog exports to foreign destinations, a development that would wreak havoc on the U.S. pork industry.
There is no current evidence the virus has reached U.S. shores so far, the closest outbreaks occurred in Cuba in 1971 and 1980, but the global outbreak has U.S. hog farmers concerned additional outbreaks worldwide could adversely affect global movement and prices of their products. Already the news of the spread of ASF has taken a toll on lean hog prices. Some recovery has been realized in recent weeks but concerns over the issue continue to feed the fires of turbidity in global pork markets.
According to Dr. Mwangi, it is not 'if' ASF reaches the U.S., but more of when it does, thanks to ease in movement of the disease from one area to the next.
In response to the threat of food security like ASF and other animal and plant diseases, USDA-APHIS has been partnering with the U.S. Department of Homeland Security's Border Protection Service and with state and local officials in developing new strategies to ensure such threats are checked at U.S. ports of entry before making their way into the mainstream of the U.S. food and agricultural industries. These strategies are intended to add a new level of security to those already in practice by APHIS, and in the case of ASF involves the use of trained canine detectors.
Earlier this month those efforts began to pay off when Hardy, a trained detector Beagle, sniffed out a roasted pig head in a traveler’s baggage at Atlanta's Hartfield-Jackson International Airport. Hardy is a graduate of USDA's National Detector Dog Center in Newnan, Ga., and one of many dogs planned to help secure airports and other ports of entry to prevent ASF from entering the country.
The center is designed and equipped to train detector dog teams (canines and handlers), like Hardy to safeguard American agriculture. USDA’s Animal and Plant Health Inspection Service Plant Protection and Quarantine program and the Department of Homeland Security’s U.S. Customs and Border Protection (CBP) use detector dog teams, known as the Beagle Brigade, to search for prohibited agricultural products at major U.S. ports of entry (airports and land border crossings), and mail and cargo facilities. The teams detect prohibited agricultural products that can carry foreign pests and diseases that threaten U.S. agriculture and forests.
“African Swine Fever is a devastating, deadly disease affecting all kinds of pigs, both domestic and wild – and keeping our pork industry safe is a top priority,” noted Sonny Perdue, U.S. Secretary of Agriculture in an official release last week. “Recently, our collaboration with CBP proved successful when [one of] our trained detector dogs intercepted a roasted pig head in traveler baggage from Ecuador.”
Perdue says ASF has been a long-standing disease around the world, particularly in sub-Saharan Africa. But recent confirmation of cases in China and the European Union in recent months prompted USDA to review and strengthen its protections. That involved partnering with the swine industry, producers, CBP, and the traveling public to protect American agriculture.
"The biggest threat in spreading the disease, and what I would consider the biggest problem with ASF, is that it is transmitted by humans―to be specific, by riding on the bottom of shoes or clothing and even the skin of humans who have come in contact with the disease," cites Mwangi. "So while trained detector dogs can sniff out food products like sausages that may be contaminated, they would not be able to detect the virus on the clothing of passengers arriving into the United States."
He says this has been the problem in China where ASF has spread rapidly, and human carriers who have unknowingly spread the disease represent the most major concern. While the disease is not a threat to the human population, the spread of the virus through human contact is significant.
Of equal or greater concern for the U.S. pork industry is the possibility that the virus could make its way into the feral swine population.
"As you know we have a significant feral hog problem in the U.S. and these wild pigs could quickly spread the disease to domestic swine. In addition, there are several ticks capable of transmitting this virus. So the threat of ASF in the U.S. is very high and the consequences could be significant to say the least.”
Mwangi says a lack of funding has so far prevented effective research on developing a vaccine that could be used to protect pigs in case of an outbreak, and he is appealing to lawmakers, farm groups and even capable private donors to contribute toward such research in order to avoid what could be devastating results if ASF is spread across the nation.
He said farmers and all others with an interest in U.S. agriculture should contact their representative in support of research funding.
"Because there’s no treatment or vaccine available for this disease, we must work together to prevent this disease from entering the United States in order to best protect our farmers, our consumers and our natural resources," said Perdue in a statement about the disease. "Good biosecurity is key to protecting pigs from any disease. We know the swine industry has many biosecurity resources available for their producers, so it’s just a matter of making sure everyone follows the guidance, every day, every time. Our goal is to never have to respond to African Swine Fever."
Animal disease officials say, however, keeping the United States ASF-free may not be a reasonable solution to the problem and point out the only real solution is a vaccine that works.
USDA is asking all veterinarians and producers to be aware of the signs of illness: high fever; decreased appetite; dullness and weakness; red, blotchy lesions on the skin, ears and snout, bloody diarrhea; vomiting, coughing; difficulty breathing, and abortion. Quick detection is key to preventing disease spread, so USDA is stressing the importance of reporting sick pigs to state or federal animal health officials immediately so that a disease investigation and appropriate testing can occur.