Thursday, August 23, 2018
African swine fever (ASF) has moved south again in China. This time it has been found in Yueqing City, Wenzhou City, Zhejiang Province, 500 miles further along the Pacific seaboard from the last reported case in Lianyungang, Jiangsu. Three farms in a breeding community had 430 pigs affected with 340 of those dying of the disease. Standard procedures of establishing perimeters, culling, and restricting movement have been put in place.
It is unclear how this disease is moving through the country. It is appearing in a range of farms across swine dense areas. Trade in pigs, semen, and pork products are all possibilities. The virus which causes ASF is hardy and has been shown to remain infectious at least 30 days in uninhabited pig pens, over four months in pork products, including salted dried hams, and indefinitely in frozen pig carcasses. The hardiness of this virus, along with the fact it is found throughout the pig as well as its feces and saliva, means these leaps of the disease across large distances are possible.
As the number of pigs affected by ASF increases, not only in China but also in Eastern Europe, the risk of introduction into North America also increases. Farm level biosecurity not only protects individual farms, but also the national herd. This illustrates the need for regular reviews with herd veterinarians of biosecurity plans and their compliance.
With the best information currently available, and until we learn more, extreme caution should be taken when considering hosting someone on US farms from an ASF, or another foreign animal disease, positive region of the world. If it is needed, the USDA Foreign Animal Disease Diagnostic Laboratory on Plum Island requires a five-day downtime for anyone planning to have contact with susceptible species after working with diseases and animals on the island.