Infection: Bacterial or Viral?
A common misconception amongst lay people is that bacterial and viral infections are the same, that in fact one is just another term meaning the other. This erroneous belief stems from the similarities between bacteria and viruses, and leads to a false sense of the impact each can have.
To be sure, both bacterial infections and viral infections are quite capable of quickly reaching epidemic or pandemic proportions, as witnessed by the great bacterial plagues of medieval times, the Black Death being the best known, or the disastrous Spanish flu viral outbreak of the early 20th century, both of which were responsible for considerable death and suffering.
Bacteria are amongst the smallest living organisms, in fact they are only single celled, and are too small to actually reproduce, so they divide into two instead, although this technique is remarkably efficient allowing bacteria to quickly increase their numbers with every generation doubling in size. Bacterial infections are therefore very difficult to fight once they reach a critical mass and the human immune system quickly needs external help in the form of antibacterial medication.
Viruses, whilst being smaller than bacteria, are not in fact living organisms, they are instead just genetic material that requires a human or other living host to allow them to multiply. Viruses attach themselves to existing cells in body damaging them in the process, and also using the cell to reproduce and so infect other cells. Because they co-opt cells into reproducing the virus, growth can be slower than bacterial infection.
Being living microorganisms, bacteria are able to survive without a host, they simply need conditions to be right for continued survival, and can quite easily survive on surfaces, inside bedding and furniture, on doorknobs, faucets, elevator control panels, keyboards, phones, and so small we don't see them. To prevent transmission, regular cleaning and disinfecting is important, especially in a hospital.
Viruses are not living organisms, and as such are not able to live for long outside a host, although this does not mean that surfaces or soft items are safe. Most viral genetic tissue is capable of lying dormant outside a host for a short time, in the case of the flu virus as much as three or four days. Disinfecting areas contaminated by viruses is an effective method of control.
Bacterial and viral infections are both very capable of spreading very efficiently from person to person thru sneezing, saliva, bodily fluids, or direct contact and are easily confused for one another. However, there are some fundamental differences, most particularly, that being living organisms bacteria are in a state of continual evolution, and are able to develop resistance to antibiotic medications.
New virus strains also appear regularly, but they don't have any ability to develop resistance, and treatment usually involves letting the virus run its course, although in serious cases antiviral medications may be prescribed.
A further difference between bacterial infection vs viral infection is the possibility of vaccination against many viral infections, something that until recently hasn't always been possible against bacterial infections.