African swine fever diagnostics
The virus may be found in sick animals in the blood, tonsils, lymph nodes, spleen and liver, among other places. Antibodies soon occur in the blood. Laboratory tests are always essential to make a definitive diagnosis.
We use the following tests at Wageningen Bioveterinary Research:
PCR on organs or blood
PCR is used to demonstrate the genetic material of the African swine fever virus. It is also a quick test that is able, within a few hours, to provide a decisive answer to whether a pig is infected with the African swine fever virus or not.
Virus isolation (VI) from organs or blood
The African swine fever virus can also be demonstrated with this test. The virus present in the blood or organs first has to be cultured on cells before it can be demonstrated using a colour method. At least five days are needed before virus isolation can provide an outcome. This test is used to confirm a first positive PCR in a region previously free of ASF and to secure virus for more detailed identification and study.
ELISA and IPMA on blood
These tests show the presence of antibodies produced by the pig. These antibodies may often be shown a little over a week following infection. The ELISA is a quick test in which many samples can be investigated at the same time. A negative outcome is known within one or two days. However, a positive result in the ELISA must be followed up with second test, the IPMA, in order to confirm the ELISA result. This test is a bit more laborious than the ELISA, but can also be conducted within one to two days.