Recent reports of African Swine Fever (ASF) outbreaks in the Dominican Republic and Haiti have heightened surveillance efforts for the highly contagious viral swine disease in the United States.

University of Missouri’s Shuping Zhang, professor and director of the Veterinary Medical Diagnostic Laboratory (VMDL) in the MU College of Veterinary Medicine, explains the dangers of ASF and the role the VMDL plays in testing for the virus to help protect animal health and the country’s agriculture industry.

What is African Swine Fever and why is it so concerning?

ASF is a highly infectious and deadly viral disease that affects both domestic and wild swine. It originated in Africa but has since spread to Europe, Asia and recently to the Caribbean.

An outbreak in the U.S. would be devastating to our economy, particularly the agriculture industry. Governments often block pork imports from countries with confirmed cases of ASF, so there would be enormous economic consequences if we were unable to continue exporting pigs and pork products abroad. A 2018 outbreak in China, where half of the earth’s pigs are located, killed more than 100 million pigs.

Have there been any confirmed cases in the U.S. yet and can humans get sick from eating pork contaminated with African Swine Fever?

The good news is there has never been a confirmed case of ASF in the U.S., and we hope to keep it that way. Also, it is not a zoonotic disease; So it is not possible for humans to get sick from ASF by eating contaminated pork.

What symptoms should pig farmers look out for?

The clinical signs of ASF include high fever, lethargy, depression, skin discoloration, and possibly vomiting and diarrhea. Other signs to look for include swollen or enlarged spleens and lymph nodes.

When Kamlendra Singh flew back to Missouri from India in April, he developed a cough and fever on the plane, despite being vaccinated for COVID-19 and testing negative for the virus right before departure.

Still, Singh tested positive for COVID-19, most likely due to infection from the Delta variant, upon his arrival home in Boone County – a diagnosis other fully vaccinated people and those who have already tested positive for the contagious virus were experiencing. He wanted to know why.

Following his recovery at home, Singh, a professor in the MU College of Veterinary Medicine and Bond Life Sciences Center, teamed up with MU undergraduate student Austin Spratt, Saathvik Kannan, a freshman at Hickman High School, and Siddappa Byrareddy, a professor at the University of Nebraska Medical Center, to analyze protein sequences for more than 300,000 COVID-19 samples of two emerging variants around the world, known as Delta and Delta Plus.

Using bioinformatics tools and programming, the team identified five specific mutations that are far more prevalent in Delta Plus infections compared to Delta infections, including one mutation, K417N, that is present in all Delta Plus infections but not present in nearly any Delta infections. The findings provide important clues to researchers about the structural changes to the virus recently and highlight the need to expand the toolbox in the fight against COVID-19.

“Whether it is natural antibodies produced from previously having COVID-19 or the antibodies produced from the vaccine, we are showing structurally how dangerous and clever the virus is by being able to mutate in a way that the antibodies don’t seem to recognize and defend against these new variants,” Spratt said. “These findings help explain why there have been so many people testing positive for the Delta variants despite being vaccinated or having previously been infected with COVID-19.”

Researchers at the University of Missouri have found chronic wasting disease – a fatal illness found in deer that affects their neurological system and causes chronic weight loss – has spread fivefold among Kansas state counties, raising concerns about the spread of the disease and the importance of educating hunters about it.

“In 2009, there were only six Kansas counties with confirmed positive cases of chronic wasting disease, and by 2020, there were 32 Kansas counties with confirmed positive cases,” said Zoe Koestel, a doctoral student at MU. “There has definitely been an increase in the prevalence of this disease, so our surveillance research will help better track the spread of the disease and possibly identify clusters or patterns, which can inform management efforts.”

Koestel works with Ram Raghavan, a professor in the MU College of Veterinary Medicine and School of Health Professions, and the Kansas Department of Wildlife and Parks, to test samples of hunted deer at MU’s Veterinary Medical Diagnostic Laboratory. After analyzing more than 1,900 samples from last year’s deer hunting season, they identified chronic wasting disease in seven eastern Kansas counties where the disease was previously undetected.

The project involves collaborating with taxidermists, wildlife biologists, game wardens and individual hunters, who collect and send the lymph nodes of their hunted deer to the MU College of Veterinary Medicine, where the samples are tested for chronic wasting disease.

“If a test comes back positive, I will call the hunter to let them know the CDC advises against eating the meat of diseased animals,” Koestel said.

Chronic wasting disease has been spreading throughout the United States for decades, despite efforts to contain it. Since it was first discovered in Colorado in 1967, the disease has now been identified in deer in 26 states, and the Midwest has seen a particularly sharp increase of its prevalence recently.

Currently, there are no reports of humans becoming infected with chronic wasting disease by eating the meat of a deer with the disease. However, similar to bovine spongiform encephalopathy, or mad cow disease, chronic wasting disease is caused by misfolded proteins called prions, which cannot be eliminated by traditional means such as cooking or heating.

There is evidence that mad cow disease can be transmitted to humans by ingestion of diseased beef. According to the CDC, four deaths from variant Creutzfeldt-Jakob disease, a human prion disease, have been identified in the United States, which has helped raise awareness regarding the consumption of meat from diseased animals.

“This project not only helps us track the spread of the disease, it also helps raise awareness for hunters because we want them and their families to stay as safe as possible,” Koestel said. “Hunters are the world’s original conservationists, and they often ask how they can help our efforts. The more samples we receive from hunters, the better we can track the spread of chronic wasting disease.”

The testing results may provide key insights on not just where the disease is currently located, but where it might be detected in the future.

“At the ‘One Health’ laboratory in MU’s Department of Veterinary Pathobiology, we investigate how wildlife and other diseases change trends in geographical areas over time, so these results provide helpful information to public health officials so more tailored management efforts may be considered,” Koestel said.