PEDv may continue to threaten U.S. pork herd this winter

The Porcine Epidemic Diarrhea virus (PEDv) has killed nearly 10 percent of the United States pork population since the epidemic began in the last half of 2013, according to the American Association of Swine Veterinarians. PEDv was found in the United States in May of 2013 on a hog farm in Ohio, and quickly spread to 30 states within just one year.

As the name implies, Porcine Epidemic Diarrhea virus targets pigs’ internal tracts and gives them diarrhea. According to the Iowa Pork Industry Center, the main symptoms include: watery diarrhea, weight loss and dehydration. The virus thrives among newborn and young piglets. The disease targets the cells in the small intestine, destroying the villi on the walls. With the villi gone from the intestine, the pigs cannot absorb nutrients and die from dehydration.

“PEDv is transmitted via the fecal-oral route and may appear to be the same as transmissible gastroenteritis (TGE) virus with acute diarrhea within 12 to 36 hours of onset,” according to the American Association of Swine Veterinarians website. “Short distance aerosol transmission may be possible. Farmers work with their veterinarians on a regular basis to monitor the health of their herds. Laboratory testing is the only way to diagnose PEDv.”

The PED virus first appeared in Great Britain in the 1970s sweeping through Europe shortly after its first occurrence. Since the first outbreak, there have been several more occurrences in Europe and it is now an epidemic virus in Asia.

To date, research has shown the virus has caused more than $1 million in damage within the hog industry. Nationally, hog farmers have seen a loss of over seven million hogs according to a USDA report from 2014.

There are several theories about how the virus entered the United States. Many scientists believe the virus came from a sickened pig, or tainted clothes, or even from workers. Not one specific source has not been identified.

Missouri and neighboring states such as Kansas and Illinois have seen their pork industries affected by this epidemic. According to a May 2014 article in Missouri Farmer Today, Illinois farmers have encountered 360 cases spread throughout the state’s 2,900 hog farms.

PEDv can spread in several ways such as via equipment used in barns, workers, trucks, and even through the air. The virus has caused an increase in biosecurity concerns across the nation. Because of this, farmers are taking more precautions in how they care for and handle their work equipment.

“We did as much as we could about it [biosecurity],” said Caleb Grohmann, a University of Missouri freshman who is also an Illinois hog farmer. “As soon as we heard about it, we built a shower house, where people have to shower in and shower out. We got disinfectant tubs and mats and we have our international customers wear coveralls and booties to enter the barns.”

Grohmann stated that the virus has not had an impact on his purebred breeding stock farm located in Red Bud, Illinois. Grohmann said Monroe County in Illinois has not been hit due to the extra precautions taken by farmers in fear of losing their stock.

“I think it will spike back up in the winter,” Grohmann said. “The virus is susceptible to heat so it thrives in the cold. It could potentially wipe out a whole farm or a segment of pigs. It will create a gap in the flow of your operation — that’s how deadly it is. Most farms won’t pull through it honestly [if hit by the virus].”

According to an online article produced by National Hog Farmer in June 2013, Paul Sundberg, National Pork Board vice president of science and technology, said the virus is not something humans will contract.

“What’s important to keep in mind is that PEDv is not a human health issue but rather a pig production disease,” Sundberg said “And we know that enhanced biosecurity measures are extremely important in containing the virus.”

As of March 1, 2014, the U. S. Department of Agriculture reported there were about 63 million hogs in the nation. Steve Meyer, president of Iowa-based Paragon Economics and consultant to the National Pork Board, told the Chicago Tribune in April 2014, that since June 2013, almost seven million of those hogs had been killed due to the virus.

“Something like a tablespoon of PEDv infected manure is roughly enough to infect the entire U.S. hog herd,” said Rodney Baker, swine biosecurity specialist at Iowa State University.

The mBio research article states that scientists have found that the strains of PEDv are closely related to a strain from China. The findings that the emergent PEDv strains in the United States share unique genetic features with a bat coronavirus further suggests a possible evolutionary origin of PEDv from bat species and a potential cross-species transmission.

According to the USDA, $1.7 million has been invested in research to develop a vaccine for this virus. The medical company Zoetis was granted permission in September to research PEDv. Yet Zoetis is not the only company looking to end the virus. Merck & Co. is also working to develop a vaccine, as well as Iowa-based company Harrisvaccines.

As of today, Zoetis has successfully created a Porcine Epidemic Disease virus vaccination. The Zoetis vaccine is a two-dose, killed-virus vaccine that is administered to healthy sows and gilts. The vaccine is designed to help the animals build immunity that can be passed on to their baby pigs.

“There are now two vaccines available to treat the Porcine Epidemic Diarrhea virus,” said Rob Christine, relationship manager for the National Pork Board. “They aid in controlling the virus spread from sow to piglet.”

The vaccines have been and will continue to be staples in fighting this epidemic.

“This vaccine is an important part of our commitment to working with veterinarians and pork producers to help minimize the impact of PEDv on pigs in their care,” said Gloria Basse, vice president for Zoetis United States Pork Business Unit. “To achieve the best possible results, producers should work closely with their veterinarians and the Zoetis technical services team to implement the new vaccine into their biosecurity programs.”

With the right precautions and vaccines, Christine continues to stay hopeful for the future of the pork industry.

“We [the pork industry] have been through several diseases over the years,” Christine said. “We got through those losses and we will make it through this one.”

Laura Bardot

About the Author Laura Bardot

I knew how to drive a tractor in a field long before I knew how to drive a vehicle on the road. I hail from a century farm in Lonedell, Missouri, and have always had a deep-rooted passion for agriculture. I grew-up on my family’s large commercial beef cattle operation and was active in the local 4-H club and FFA chapter during my youth. I am excited to be writing for Corner Post for my third semester. Corner Post has provided me with several great writing opportunities for stories in the past and I look forward to the stories that come from this semester.