Recent outbreaks of African swine fever (ASF) in Eastern Europe have led to the growing need for more accurate diagnostics to help identify and monitor the highly contagious pathogen, for which no treatment or vaccine currently exists.

Scientists from Thermo Fisher Scientific have presented research data from a new duplex real-time polymerase chain reaction (PCR) kit that demonstrates the ability to accurately detect the virus with high sensitivity and specificity in animal samples.

Results of the detection kit showed 100% sensitivity in all tested sample materials, including blood, serum and tissues, and 100% specificity. No cross-reaction was found with other pathogens, and a serial dilution of the ASF virus target sequence led to a limit of detection of 16 genome copies per PCR reaction. The kit fulfills all of the validation criteria for PCR characteristics, and the complete method conforms to the requirements described in the French norm NF U47A-600.

“African swine fever virus is a complex virus that can’t be identified from classical swine fever by either clinical or postmortem examination,” said Sandrine Moine, research and development manager at Thermo Fisher Scientific and first author of the study presented at the Annual Meeting of the Society for Veterinary Epidemiology & Preventive Medicine in March. “Since there is no vaccine or treatment, we felt it was of the utmost importance to develop a highly sensitive and accurate diagnostic test to help monitor and control the disease in animals."

To demonstrate the accuracy of the detection kit, Thermo Fisher conducted field studies in France and the Netherlands with samples from Spain, the Netherlands and Germany. Researchers tested about 1,600 negative samples from ASF-free regions in Germany and Spain and 33 different pathogens other than ASF to demonstrate the analytical specificity of the assay. Additionally, about 100 samples from Africa and Eastern Europe previously identified as ASF-positive were tested to determine the test’s sensitivity.

A DNA virus from the Asfaviridae family, ASF infects all Suidae (domestic and wild animals) but is not a human health threat. The virus is found in all bodily fluids and tissues of infected pigs. They usually become infected by direct contact with sick animals or by ingesting infected products. The virus is highly resistant in the environment.

ASF disease is characterized by high fever, loss of appetite and hemorrhages of the skin and internal organs; death can occur within 2-10 days. ASF cannot be differentiated from classical swine fever by either clinical or postmortem examination. It is an economically important disease that is widely endemic in many parts of Africa and has become an emerging threat in Eastern Europe.