Differentiating Transboundary Animal Diseases in a Single Test

VETLAB Network scientists learn how to use the multi-pathogen assay. (Photo: IAEA)

Peste des petits ruminants (PPR) is a highly contagious disease of small ruminants, which endangers the lives of sheep and goats in more than 70 Asian and African countries, as well as the livelihoods of their owners. PPR spreads very quickly from animal to animal, through direct contact, movement of infected animals or contaminated material. Early detection and confirmation of the disease is essential for its effective control and eradication.

Following the successful global eradication of rinderpest in 2011, the eradication of PPR by 2030 has been set as a goal by the Food and Agriculture Organization of the United Nations (FAO) and the World Organization for Animal Health (OIE). The IAEA, in partnership with the FAO through the Joint FAO/IAEA Division of Nuclear Techniques in Food and Agriculture, has developed a multi-pathogen assay at its Animal Production and Health Laboratory in Seibersdorf, Austria, that was validated in collaboration with veterinary laboratories from the VETLAB Network. The assay simultaneously detects the PPR virus and other pathogens causing similar signs of disease. Thanks to this innovative method, Member State scientists are now able to diagnose diseases more efficiently, both in terms of time and costs.

Specifically, the multi-pathogen assay focuses on microorganisms that cause respiratory diseases of small ruminants, such as PPR, capripox disease, pasteurellosis and contagious caprine pleuropneumonia. This new diagnostic assay enables scientists to detect and differentiate the pathogens responsible for the four diseases in one single rapid test. In fact, these diseases have the same outward symptoms in small ruminants, including fever and discharge from the eyes and nose, making it difficult to distinguish between them clinically. “If diagnosticians only test for the most common respiratory diseases in their area, they might miss when PPR or other diseases enter their area,” said Charles Euloge Lamien, a scientist at the Animal Production and Health Laboratory.

The assay was transferred to Member State scientists during a recent two-weeks training course held at the Seibersdorf laboratories. The participants were from Asian and African laboratories of the VETLAB Network, which operates at the national and international level. The Joint FAO/IAEA Division is actively coordinating and supporting this network of national animal disease diagnostic laboratories in 40 African and 17 Asian countries.

The Science

Multi-pathogen assays are rapid laboratory tests that look for different microorganisms (i.e. bacteria and viruses) responsible for animal diseases in one single reaction, thus saving time and money. The Animal Production and Health Laboratory uses these tests to diagnose the specific illnesses of sick animals as quickly as possible.

Pathogens are the causative agents of infectious diseases; they can be passed easily from one animal to another. To properly treat the animals and contain the outbreak, the specific causative agent has to be identified. Since distinct pathogens may exhibit similar signs of disease, identification is not always possible based on clinical examination of the animals, which makes the laboratory test essential. Using the multi-pathogen assay, scientists can now determine exactly what pathogen is present using only one test.

Samples are first taken from the infected animals and then processed in the laboratory and analysed in a real-time polymerase chain reaction platform, which reveals the presence and the type of pathogen. This test was developed by the Animal Production and Health Laboratory and validated in collaboration with veterinary laboratories from the VETLAB Network.