Controlling Infectious Diseases

Controlling Diseases

Pathogens

Pathogens are microorganisms usually bacteria or viruses that cause infectious diseases.

Microorganisms which cause disease reproduce rapidly inside your body.  They could produce toxins that may make you feel ill.

Viruses are much smaller than bacteria.

Viruses damage your cells as they reproduce.  They can also make you feel ill.

Defence Mechanisms

The body prevents most pathogens coming in.

Your body has several methods of defending itself against the entry of pathogens using the skin, the mucus of the breathing system and the clotting of the blood.

Pathogens can be killed by stomach acid.

White blood cells help defend against pathogens by ingesting them, making antibodies and making antitoxins.

Using drugs to treat disease

Some medicines can relieve the symptoms of the disease but not kill the pathogens that had caused the symptoms in the first place.

Antibiotics cure bacterial diseases by killing the bacteria inside your body.

Antibiotics can't destroy viruses.

Viruses are diffucult to destroy because they reproduce inside body cells.

It is diffucult to develop new drugs that can destroy the pathogens but not kill healthy body cells.

Changing Pathogens

If a pathogen changes by mutation the …