How ASF Spreads
#16,205
In early August, in DEFRA: Preliminary Assessment Of ASF Outbreak In the Americas (Dominican Republic), we looked at the first detection of African Swine Fever (please, don't call it `Flu') in the Americas in nearly 40 years.
While African Swine Fever (ASF) doesn't affect human health directly, it has reportedly killed somewhere between 1/3rd and 1/2 of the world's swine over the past decade - mostly in Asia and Eastern Europe, which can lead to economic and food insecurity.
In 2018-2019, the global spread of ASF increased markedly - particularly due to outbreaks in China and Southeast Asia - after smoldering in Eastern Europe and Russia for the better part of 10 years. ASF poses a constant threat to spread to unaffected regions, including the United States and Canada (see USDA Enhances Domestic ASF Surveillance Efforts).
Although African Swine Fever can be transmitted directly from pig-to-pig, and can be carried by certain types of ticks, in many cases the virus has been spread by the movement of contaminated food products, animal feed or bedding, or other products to uninfected regions.
In October of 2019, just 3 months before our attentions were diverted by COVID, in Nature Sci. Rpts: Risk of African Swine Fever Virus Introduction into the United States, we looked at the very real possibility of this virus being imported into the United States.
While North American remains free from the ASF virus, the more inroads it makes around the globe, the more opportunities it will have to jump into our backyard (see USDA's A qualitative assessment of the likelihood of ASF virus entry to the United States. March 2019).Earlier this week it was announced that a second Caribbean nation - Haiti - has now reported African Swine Fever, effectively ratcheting up concerns over its further spread. First, the following statement from the USDA/APHIS, then I'll return with a postscript.
USDA Statement on Confirmation of African Swine Fever in Haiti
Published: Sep 21, 2021
Contacts:
Mike Stepien
Mike.Stepien@usda.gov
Lyndsay Cole
Lyndsay.m.cole@usda.gov
On September 20, the Chief Veterinary Officer in Haiti reported a positive case of African swine fever (ASF) to the World Organisation for Animal Health. The sample was collected from a pig in a province bordering the Dominican Republic and was tested by the U.S. Department of Agriculture’s (USDA) National Veterinary Services Laboratories through a cooperative testing program.
ASF is not a threat to human health, cannot be transmitted from pigs to humans and it is not a food safety issue.
While unfortunate, this detection is not unexpected due to the recent cases of ASF in the Dominican Republic. USDA’s Animal and Plant Health Inspection Service (APHIS) is committed to assisting both Haiti and the Dominican Republic in dealing with ASF and continues to consult with animal health officials in both countries to support response and mitigation measures.
APHIS has numerous interlocking safeguards in place to prevent ASF from entering the United States. Pork and pork products from the Haiti and the Dominican Republic are prohibited entry to the United States as a result of existing classical swine fever restrictions. After ASF was detected in the Dominican Republic, APHIS increased surveillance and safeguards in U.S. territories. These safeguards will also help prevent the spread of ASF to the United States from Haiti.
APHIS continues to work diligently with partners including the Department of Homeland Security’s U.S. Customs and Border Protection (CBP) and the U.S. swine industry to prevent ASF from entering the United States. CBP is increasing inspections of flights from Hispaniola to ensure travelers do not bring prohibited products to the United States. CBP will also ensure that garbage from these airplanes is properly disposed of to prevent the transmission of ASF.
On August 26, APHIS announced our intent to establish a Foreign Animal Disease protection zone in Puerto Rico and the U.S. Virgin Islands. ASF has not been detected in Puerto Rico or the U.S. Virgin Islands, and APHIS is committed to keeping it out of both islands and the rest of the United States. As part of the actions taken to create the protection zone, on September 17, APHIS issued a Federal Order suspending the interstate movement of all live swine, swine germplasm, swine products, and swine byproducts from Puerto Rico and the U.S. Virgin Islands to the mainland United States until APHIS can establish sufficient mitigations to authorize such movement. USDA is taking these actions out of an abundance of caution to further safeguard the U.S. swine herd and protect the interests and livelihoods of U.S. pork producers.
More information about USDA’s efforts may be found at https://www.aphis.usda.gov/aphis/ourfocus/animalhealth/animal-disease-information/swine-disease-information/african-swine-fever/seminar.
Just over a month ago, in Science Perspective: The Animal Origin of SARS-CoV-2, we looked at speculation that the dire shortage of pork in China in 2019 caused by their ASF epizootic may have driven many more people to eating bushmeat - often sold illegally in wet markets - and that may have led to the emergence of the SARS-CoV-2 virus.
While unproven, it wouldn't be the first time.
While surveillance and reporting on spillover events remain limited, we see scattered reports of avian flu infecting humans, human anthrax infection from infected livestock, strep suis (see Tiết Canh - An Incredibly Bat Idea, bubonic plague (see China: Inner Mongolia Reports Another Plague Case), Nipah, and Ebola linked to animal contact and/or consumption every year around the globe.
Six weeks before the 2019 Wuhan outbreak, in African Swine Fever's (ASF) Other Impacts; Pharmaceuticals, Bushmeat, and Food Insecurity, we actually looked at the potential for another SARS-like virus to emerge in China due to the devastating impact of ASF on China's pork supply.
