What is mad cow disease, viral or bacterial?

Slow virus. It's viral. It is a type of infection in which infection may not be evident for decades. Slow viruses are notoriously difficult to culture but advanced dna techniques and electron microscopy can prove their presence.
Prion. This is an abnormal protein, neither a virus nor a bacterium. It is an altered version of a normal brain protein that catalyzes the transformation of this protein into copies of itself.

Related Questions

What bacteria and viruses are in mad cow disease?

Neither. Mad cow disease is more correctly known as bovine spongiform encephalopathy (bse). It is believed that the infectious agent in bse is a prion. Prions are proteins, neither viruses nor bacteria.

Is mad cow disease related to gliosis?

No. Mad cow disease is believed to be a disease caused by the build up (and transmission) of a certain protein in the nerves of our brain. The resultant damage can cause gliosis, but gliosis can also occur in a variety of conditions other than mad cow disease. Gliosis is a term to explain "scarring" in the brain that could be caused by trauma, infections, tumors, radiation therapy, etc.

How rare is mad cow disease?

Rare. From my reading, there has been a single human case in the usa, one in ireland, a few hundred in the united kingdom because of the unsafe cattle farming practices in the past, and very few elsewhere. By contrast, maybe one person in a million each year gets a classic prion disease such as cjd.
MAD COW DISEASE. Although cjd (creutzfeld jacob disease = mad cow)is the most common human prion disease, it is still rare, occurring in about one out of every one million people every year. It usually affects people aged 45–75, most commonly appearing in people between the ages of 60–65.
Rare except for. The huge outbreak of the disease about 2 decades ago in the uk that spilled over into europe. Very few cases in the usa. In the wake of this, a human disease, called varient creutzfeldt-jakob disease, was linked to eating contaminated beef. Several hundred cases have occurred in europe but none have been acquired in the usa.
The epizooic of. Bovine spongiform encephalopathy in the uk primarily is essentially over and there have been no human equivalents (so called variant creutzfeldt-jacob syndrome).

How is mad cow disease spread?

Read below. Bovine spongioform encephalopathy (mad cow disease) is a prion disease, infective agents that vary from viruses in not having dna or rna. The agent can be transferred by ingestion or surgery transplanting the infected tissue (e.g. Cornea) it is fortunately extremely rare for this to happen nowadays.

Is mad cow disease still around? Never hear about it anymore

Few. Between 2003 and 2012 there have been 21 cases and deaths of mad cow disease (bovine spongiform encephalopathy) among cattle in north america.

How does mad cow disease spread?

Eating bad beef. Infected cattle, which got the disease by eating animal by-products, produce infectious beef. The prion is not damaged even by thorough cooking. It is also possible that slaughterhouse workers exposed to aerosolized cattle parts might be infected in this way.
Variable. Conceive that ingestion or contact with the prion infection could result in the disease, so best not to eat the raw meat, or even the cooked meat, if infected, or get an organ transplant from a human who has the illness. But, do not worry, the cases occurred in england, not in the usa.