Pandemics, like the influenza-pandemic, are of great danger.
The possibility of a major pandemic in the near future is very likely.
Whether plague, EHEC, Ebola, avian flu or other viruses and bacteria a global or continental pandemic in our society of the 21st century cannot be excluded.
On the contrary, in densely populated countries and the highly networked society, a very contagious disease could spread very easily.
Many viruses and bacteria adapt to the people, i.e. they are immune to common drugs and can develop further.
Climate change and the associated increase in temperature provide new habitat for existing or previously unknown viruses in many places on earth.
Many life-threatening viruses artificially kept to live in sealed laboratories. However, some nations argue, that it is important to keep some of this viruses alive, so that in case of a threat, they are able to run some tests.
So, a global contamination by viruses, bacteria and other infectious diseases is a realistic danger.