Thursday the World Health Organization was back doing what it is supposed to be doing, reporting on real disease outbreaks rather than speculating on remote cell phone risks.

There is a new strain of toxic bacteria that is sickening people in Europe. Because the bacteria is so toxic, it has the potential to become the deadliest outbreak in recent history. So far, more than 1,500 people have become ill, 470 have developed a kidney complication from broken down blood cells which can be life threatening, and 18 people have died.

The bacteria is an E coli, a common rod-like strain of bacteria which makes a toxin. It is usually the toxin which sickens people, and so it is in this case.

Why is this happening?

For one thing, bacteria breed in millions of colonies, and are constantly mutating and exchanging genetic material. New strains come about all the time, breeding in the guts of animals, and by Darwinian principles, the fittest survive. E coli live in the intestines of animals -- including cows. By feeding cows grain instead of the grass they are intended to eat, we make their guts more acidic, making it easier for this type of bacteria to thrive. From cow intestines, the bacteria makes its way into manure and on out into our crops and our ground water, where it spreads easily to humans.

Another problem is our overuse of antibiotics, both in animals and in humans, which creates an environment where it is very easy for resistant strains of bacteria to thrive. This is something we need to become more conscious of, especially when you consider that newer antibiotics are not being made to replace the ones that are no longer effective. Drug companies long ago discovered that making antibiotics is not a profitable business.

As the new bacteria spreads throughout Europe via vegetables, a second pathogen is spreading along with it. That pathogen is fear. Since bacteria are invisible, we all personalize the risk and imagine we could be the next victim.

In this case panic is already spreading throughout Europe. Russia has already banned vegetable imports, the United Arab Emirates is banning cucumber imports from parts of Europe; a precautionary move but one which is also certain to spread more...fear.

People being are told to wash their vegetables and wash their hands, a seemingly practical move which actually does little to protect us since this type of bacteria is so virulent and so tiny that we can’t wash enough of it away to stop it.

In the end this bacteria will likely die out, be replaced by another one, or take its place among the various pathogens that concern us. It may survive, but the fear will fade, the hysteria will lessen, and ultimately it will be science and epidemiology which will predict this bug’s future.

Marc Siegel, M.D. is a professor of medicine and medical director of Doctor Radio at NYU Langone Medical Center. He is a Fox News Medical contributor and author. His latest book is "The Inner Pulse: Unlocking the Secret Code of Sickness and Health."