Mad Cow Disease: What You Need To Know (April 2012)

Mad Cow Disease: What You Need To Know Now
April 25, 2012
http://www.npr.org/blogs/thesalt/2012/04/25/151357194/mad-cow-disease-what-you-need-to-know-now

Mad cow disease has been detected in a cow in California, the first time since 2006 that the deadly disease has surfaced in the U.S.

this cow had a rare form of bovine spongiform enceph alopathy, mad cow’s official name, that is caused by a spontaneous mutation. That’s different than getting the disease from eating feed made out of bone and tissue from infected cattle, which caused the outbreaks in England in the 1980s and 1990s.

a testing program mandated by the USDA after mad cow disease was first discovered in the United States in 2003.

That’s just a tiny percentage of the 34 million cattle slaughtered in the U.S. in 2011. But the testing is supposed to focus on older cattle or sick cattle most likely to be infected.

This case brings the mad cow count in the United States up to four.
That includes the first case, in Washington state in 2003; one cow in Texas in 2005; and one in Alabama in 2006.

Prions were first discovered by neurologist Stanley Prusiner in the 1980s.
They remain mysterious, and there’s no consensus on what causes them to form.

People can get Creutzfeldt-Jakob disease from spontaneously generated misfolding of proteins in the nervous system.
Or they can get it from eating meat from an infected cow.

reducing the number of cases of mad cow worldwide from 37,311 in 1992 to 29 in 2011.

Prion diseases affect the nervous system, and there’s no evidence they’ve ever been transmitted by drinking milk.

The federal Centers for Disease Control and Prevention estimates that mad cow disease affects 0.167 cows per million in the United States.

Surgical instruments & ‘mad cow’ disease

NHS failed to sterilise surgical instruments contaminated with ‘mad cow’ disease
The Independent. 30 November 2013
http://www.independent.co.uk/news/science/nhs-failed-to-sterilise-surgical-instruments-contaminated-with-mad-cow-disease-8967763.html

variant Creutzfeldt-Jakob disease (vCJD)

the lethal prion protein, which sticks to the stainless steel of surgical instruments like superglue and can survive the high temperatures of hospital autoclaves.

“The solution we developed was a combination of enzymes and detergents, if you like a sort of bespoke biological washing powder which very effectively prion-decontaminated metal surfaces,” Professor Collinge said.

“They’ve had to be notified that they’ve had a significant exposure to prions because they are expected to take precautions. They are not allowed to be blood donors and if they go on to have surgery they have to notify the surgeons that they are high risk individuals.

DuPont, an American chemicals company, worked out a way of manufact uring Professor Collinge’s product as a 50C pre-soak for surgical instruments, but because this would involve changing the standard procedures for how medical devices were sterilised, NHS hospitals refused to adopt it

About 200 hospital patients have been told that they have been exposed to the vCJD prion through instruments that were used on other patients who subsequently died of the brain disease. Three out of the 177 people in the UK who have died of vCJD received contaminated blood, and the rest are assumed to have been infected by meat or meat products contaminated with bovine spongiform enceph alopathy (BSE).

There are fears of secondary infections from asymptomatic carriers in the population. Latest estimates suggest that up to one in 2,000 people in Britain could be carriers of vCJD.

Because the prion protein responsible for vCJD is found in a wide range of tissues, such as spleen, tonsils and appendix, the fear is that asymptomatic carriers may spread the infection to others through contaminated surgical instruments and blood donations.