African swine fever

African swine fever (ASF), highly contagious, deadly viral disease of swine. Its acute form, which is typically fatal, is characterized by high fever, loss of appetite, lethargy, and redness in the skin or red blotches or blackened lesions on the skin; other symptoms include vomiting, coughing and other respiratory symptoms, diarrhea, and miscarried pregnancies. Less virulent forms of the virus may cause chronic disease with loss of appetite, low fever, listlessness, coughing and other respiratory symptoms, and other symptoms, and the death rate is lower but may reach 70%. There is no vaccine. The disease is controlled by slaughtering exposed herds and disposing of the carcasses in a sanitary manner, and other sanitary measures. Although symptoms are similar to classical swine fever, the causative viruses are not related. The virus does not affect humans.

ASF is transmitted readily by direct or indirect contact. The virus may enter a herd through contaminated feed, water, equipment, clothing, or by contact with an infected animal. Feeding swine pork scraps is forbidden in some areas to prevent transmission. It also may be transmitted by some species of soft ticks, which may transmit the disease to domestic swine from wild boars and feral swine as well as from warthogs, bush pigs, and other species that can carry the disease. Outbreaks of ASF have never occurred in the United States, and it is currently eradicated in the Western Hemisphere. An outbreak that began in NE China in 2018 and continued into 2019, spreading to other E and SE Asian countries, became the most devastating animal disease outbreak known, with significant economic consequences.

The Columbia Electronic Encyclopedia, 6th ed. Copyright © 2024, Columbia University Press. All rights reserved.

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