October 2017
From the State Vet's Office

It Always Happens on a Friday

Alabama has second BSE-positive cow in 11 years.

In case anybody wants to know, my birthday is July 14. This year it fell on a Friday. So right in the middle of cake, ice cream and having "Happy Birthday" sung to me, I got a phone call from my federal counterpart in Tennessee. He said one of our samples from Alabama was suspect and the lab would work over the weekend to confirm if it was positive. The cow was tested as part of routine surveillance of testing adult cows that die of an unknown origin.

Immediately, I had flashbacks to the Friday when I was trying to take a vacation and Dr. Hatcher from Tennessee called to give me a heads up about the highly pathogenic avian influenza in his state. It was late on a Friday when I got a call telling me we were probably going to have some avian influenza tests on a farm in North Alabama.

But, in all fairness, it was a Saturday when I got the call March 11, 2006, when I heard about our first BSE-positive cow. And, oddly enough, it was the Tennessee State Veterinarian at the time, Dr. Ron Wilson, who called to give me the news that day.

I am beginning to see some kind of pattern that I don’t like involving me, animal health officials in Tennessee and the end of the week.

Sure enough, I got the call Sunday that confirmed the cow had indeed tested positive for atypical bovine spongiform encephalopathy. That is probably better than not being atypical. Atypical is generally considered to be a spontaneous mutation by a protein becoming the agent affecting the brain in such a way that, when you look at it under a microscope, it looks like a sponge.

So, as usual, it was all hands on deck. We had to trace the cow back to the farm of origin. That is a requirement our trade partners expect from us when we have a positive cow. Within two weeks, we had the case wrapped up because of the excellent records the farm of origin kept on their animals. With a lot of diligent work by our state animal health employees and our federal colleagues, we were able to finish fairly quickly.

I cannot overemphasize the importance of keeping good records and following the animal disease traceability regulations. By the way, we were never able to trace the 2006 cow to a farm of origin because of no identification. That cow had never even had a fly tag in her ear.

BSE is caused by a prion – not a virus, bacteria or toxin but an abnormal protein known as a prion. It is part of a group of prion diseases known as transmissible spongiform encephalopathies. Prion diseases are bad diseases and generally cause the demise of their victims. Fortunately, they are not too common and are usually very species specific.

There are a few prion diseases that affect humans. Creutzfeldt-Jakob disease is the most common prion disease that affects humans. It generally occurs at a rate of two to three cases per 1 million people in most of the civilized world. Once neurological symptoms begin, death occurs within a year. That is the case with most TSEs.

Kuru is a TSE affecting certain people in New Guinea. The specific tribe suffering from Kuru believes that by eating the brains of their ancestors they could absorb some of the wisdom from their elders. Kuru peaked in the 1950s and ’60s, and only a rare case surfaces now and then due to the long incubation period.

Familial fatal insomnia is another prion disease affecting humans. In 1998, there were 25 families worldwide who were known to carry the gene causing this inherited disease. Apparently, when people get this disease, they eventually die from lack of sleep.

TSEs affecting animals are scrapie in sheep and goats, transmissible mink encephalopathy in mink, chronic wasting disease in deer and elk, feline spongiform encephalopathy in cats and, of course, BSE in cattle. There are speculation and evidence of certain mutations of some of the prions in one species causing another prion disease in another species. It is possible, but not proven, that CWD in deer and elk originated from scrapie. The same is possible for BSE being linked to scrapie. However, these diseases do not usually jump from one species to another.

BSE was first recognized in the United Kingdom in 1986. It is thought that offal from sheep containing the scrapie prion was used to make meat and bone meal, and put into cattle feed. The U.K. had over 180,000 cases of the disease, peaking in 1993 when they were reporting about 100 new cases per week. BSE was found on over 35,000 farms in the U.K. Depending on the source, over 4 million animals were destroyed in the eradication program. The nonagricultural community became interested in BSE when, in 1996, the British Minister of Health suggested there was a likely link between BSE and a new variant of CJD (remember the human prion disease). The most significant difference between the original CJD and its variant was the variant affected mostly people under 40 years old. The original CJD usually affects people over 65.

At that point in 1996, the United States Department of Agriculture and state veterinarians across the United States located and quarantined all cattle in the country imported from the U.K. These animals were either purchased and destroyed or they remained under quarantine until they died naturally and were tested for BSE. Additionally, as of 1997 ruminant by-products were no longer allowed to be put into cattle feed. Then very rapidly, other practices were put into effect to make sure no bovine tissue likely to contain prions were allowed into the food chain … period. That meant that no brain, spinal cord tissue or other tissues that might contain prions from cattle over 30 months of age could even be used in pet food. And nonambulatory cattle cannot go into the food chain.

There has also been a BSE surveillance program conducted for a long time. If you look at the USDA Veterinary Services information, the surveillance has been in place since 2007. And, in its current form, that would be correct. However, there has been a BSE surveillance program of some type since at least the early 2000s. That is how the first cow with BSE in the United States was found back in December 2003, the Texas cow in 2005 and the first Alabama BSE cow in 2006. Since the program evolved in 2007 to what it is today, there has been a positive cow in California in 2012 and the cow that put Alabama back in national news in July of this year.

Finally, I do want to thank all of those who helped work on tracing the positive cow. That includes our federal partners, the folks here at the Department of Agriculture and Industries and especially Commissioner McMillan, who is always very supportive and shows great leadership when we have critical events pop up. I also want to thank Nate Yeager from the Farmers’ Federation and our friends at the Alabama Cattlemen’s Association for helping educate both producers and consumers. I truly believe that education made the difference between the cattle market dropping like a lead balloon in 2003 when the United States had its first BSE-positive cow and the results from the event in July. Because of the intense education efforts over the last few years, the market just yawned.

So we will continue to take samples from target animals to show that we earn our status as minimal risk for BSE. But I am thinking I may quit answering my phone on Fridays and Saturdays.

And I am not telling you how old I turned July 14!

 

 

 Dr. Tony Frazier is the State Veterinarian for Alabama. You can contact him at 334-240-7253.