Earlier this year, a virology laboratory in Tunisia received the oral samples of cows suspected by veterinarians of having foot and mouth disease (FMD). FMD is a highly contagious disease that affects cloven-hoofed animals, such as cows, pigs and goats, and it can lead to the disruption of regional and international trade of animals and animal products. The disease is characterized by fever and blister-like sores between the hooves, in the mouth and on the tongue and lips.
Within days of submitting the samples to a genetic sequencing service, Soufien Sghaier, a virologist at the Virology Laboratory at the Institute of Veterinary Research of Tunisia (IRVT), received results that helped confirm the circulating strain of FMD. Sghaier was able to notify veterinary authorities to implement control measures to prevent the disease from spreading. The timely confirmation was made possible by the IAEA, in partnership with the Food and Agriculture Organization of the United Nations (FAO), which facilitates the sequencing service and provides the training needed to process the results.
“We received the sequencing results from a FMD suspicion very quickly. Samples were sent to a laboratory in Berlin on Friday, and we received the sequencing results on Monday afternoon,” Sghaier explained. “This allowed us to perform an analysis to identify the specific strain of FMD in a record time – less than a week from receipt of samples. By Tuesday, we sent the report on the FMD strain to the veterinary authorities.” The strain of FMD needs to be identified to select or develop an effective vaccine.
Genetic sequencing is important to determine if a circulating disease is endemic – or typically found in a certain area – or transferred from another region. “Genetic sequencing can help to understand which cluster a pathogen – an organism that causes disease – belongs to and which vaccine is effective against the pathogen,” said Ivancho Naletoski, Animal Health Officer at the Joint FAO/IAEA Centre of Nuclear Techniques in Food and Agriculture. “Sequencing is also important in helping to identify the patterns of mutation of the pathogens.” Based on genetic sequencing, a phylogenetic tree can be created, which maps the lineage of a species.
“With our phylogenetic analysis, we determined that we already had a vaccine that could protect our cattle. The veterinary authorities implemented perifocal vaccination to reduce the risk of FMD spreading,” Sghaier said. Perifocal vaccination, or buffer vaccination, is implemented within a zone around the affected area to prevent spill over of the virus to other regions.
