By DOUG SCHMITZ
LAKEWOOD, Colo. — For the first time in the United States, porcine epidemic diarrhea (PED), which was initially detected in hogs on Iowa and Indiana farms, was also confirmed May 22 in hog herds in Minnesota and Colorado, according to samples tested at the USDA’s National Veterinary Services Laboratories (NVSL) at Iowa State University in Ames.
“Further testing and epidemiologic investigation will be available later in the week and may reveal a deeper understanding and background of the disease outbreak,” said Colorado State Veterinarian Dr. Keith Roehr, investigating possible cases of the swine virus in the state. “I encourage swine owners to contact their local veterinarian if they observe clinical signs of the virus in their herd.”
On May 21, Dr. Lisa Becton, D.V.M. at the National Pork Board (NBB) in Des Moines, first confirmed PED on one Indiana and three Iowa hog farms, which all tested positive for the swine virus. “The severity of the outbreak is not yet known, but we’re hoping to have a better assessment soon,” Becton told Reuters last week.
According to Roehr and information released by the NVDL and the Iowa Pork Industry Center at ISU, PED is a viral disease associated with outbreaks of diarrhea and vomiting in swine. PED is not a zoonotic disease – it does not affect people – and is not a food safety concern.
PED symptoms like TGE
The clinical signs of PED include severe gastroenteritis, dehydration, diarrhea, vomiting and death in young pigs. In pigs younger than seven days of age, mortality can reach 100 percent, Roehr added. Older pigs may only show vomiting, diarrhea and anorexia.
First diagnosed in 1971 in Great Britain, PED exists in many parts of the world. Since that time, there have been sporadic outbreaks in Europe and it has become an endemic pig disease in Asia as of 1982, according to ISU’s College of Veterinary Medicine in Ames.
Since then, the disease has been identified in a number of European countries and Canada, and more recently in China, Korea and Japan.
“This is not a new virus, nor is it a regulatory/reportable disease,” Becton said. “Since PED is widespread in many countries, it is not a trade-restricting disease, but rather a production-related disease. PED may appear clinically to be the same as transmissible gastroenteritis (TGE) virus, with acute diarrhea.”
There are no interstate trade restrictions pertaining to PED in the United States. Collaborative work is now being done among the USDA, state animal health officials, the USDA’s NVSL in Ames, practicing veterinarians, swine producers and related swine industries to manage the U.S. outbreak of PED, according to a May 21 statement from the Colorado Department of Agriculture.
“Although this is the first known detection in the United States, PED exists in many parts of the world and is not considered a foreign animal disease in the U.S., but rather a trans-boundary disease,” said Harry Snelson, director of communications at the American Assoc. of Swine Veterinarians (AASV) in Perry, Iowa.
“We are in contact with the USDA, state animal health officials, the National Pork Board and National Pork Producers Council. The federal and state animal officials are monitoring the situation. Development of an epidemiological survey instrument has begun. It is expected that herd veterinarians will be actively involved in the information-gathering.”
Snelson said U.S. veterinarians should contact a veterinary diagnostic laboratory to determine what samples are preferred for that lab. The USDA’s NVDL at ISU is well prepared to diagnose PED and other pathogens that may mimic PED, he added.
“Currently, testing capacity to detect PED is limited, so turnaround times on testing will be slower than typical for routine testing at NVDL. However, high-capacity PED tests are currently being developed and will soon be implemented,” he said.
“In general, desired samples are live pigs in acute stages of disease, several segments of fresh and formalin fixed small intestine and colon from several pigs euthanized in the acute stage of disease, fresh feces from acutely affected pigs and tissue from a variety of other organs as appropriate.”
Keep clean and hydrated
Becton said PED is transmitted via the fecal-oral route and may appear to be the same as TGE with acute diarrhea within 12-36 hours of onset. “Herd veterinarians remain well-versed in managing TGE-like diseases,” she said. “Laboratory testing is the only way to diagnose PED. As always, producers who see any signs of illness in their pigs should notify their herd veterinarian immediately to address the issue.
“PED does not affect pork safety. Pork remains completely safe to eat.”
According to information released May 21 by Michigan State University extension, morbidity in sows and piglets is high, and especially high in piglets (up to 80 percent) because of dehydration.
“If your herd is exposed to the virus, suckling pigs should have free access to water to help decrease dehydration and gestating sows can be exposed to the virus to help build immunity in piglets, similar to methods used with a TGE outbreak,” it read. “Sanitary and quarantine measures can help to slow the spread of the virus.
“Introduction of new stock should also be suspended during an outbreak, along with increased internal biosecurity practices to help decrease the spread of disease within your herd. Contact your veterinarian if you suspect PED or TGE, to develop testing and immune response strategies.”
Although all transmission routes of PED have not been confirmed, MSU stated it is suspected to be transmitted via infected pigs, transportation vessels and contaminated fomites, such as clothing, footwear and equipment.
Because of the severity and unknown origin of the swine virus found last week, Beth Ferry and Madonna Benjamin of MSU wrote in a May 21 statement that several top U.S. agricultural officials have issued a biosecurity alert to U.S. pork producers and veterinarians.
“In order to help protect your herd from possible infections, review your biosecurity plans and strategies to increase biosecurity protocols,” they wrote. “These strategies would include washing and disinfection protocols for all trucks returning from market, change of footwear, change of outerwear such as coveralls and washing hands prior to entry to the barns where pigs are housed.”
Snelson said the AASV will keep producers and veterinarians updated as more details become available. To learn more, visit http://vetmed.iastate.edu/ vdpam/disease-topics/porcine-epidemic- diarrhea-ped-diagnostic-testing
In addition, the AASV has posted a fact sheet about PED (including links to publications) on its website at www.aasv. org/aasv%20website/Resources/Diseases/PEDAASVQuickFacts.pdf and an update on detection in the United States at www.aasv.org/members/only/PED/ PEDDetectioninUSSwine05172013.pdf