Pathogenic Organisms

Infections and infectious diseases in humans are caused when harmful germs, known as pathogens (or pathogenic micro-organisms), enter the body and grow. These micro-organisms are so small they can only be seen using a microscope.

Pathogenic Organisms can be:

Bacteria that can multiply quickly at body temperature and reach harmful levels very fast. Examples of harmful bacteria include methicillin resistant Staphylococcus aureus (commonly known as MRSA) and Clostridium difficile (known as C.Diff or C.Difficile). These two types of bacteria caused, or contributed to, 9000 deaths in hospitals or primary care in 2007.

Viruses that can survive on surfaces and in food can only multiply in living cells. It takes very few organisms to cause illness. They can be spread from person to person and from environment to food. Examples of viruses include Norovirus (also known as ‘winter vomiting disease’) and influenza (the flu virus).

Fungi are organisms which live on hosts that can be alive or dead. Examples of fungal infections include; athlete’s foot and ringworm. (A host could describe the organism from which the parasite feeds or in which it lives or grows)

Parasites live on or in another plant or animal, known as the host. Scabies is caused by mites that burrow into the skin causing severe itching.

Protozoa are single-celled organisms that live in water and damp conditions. Malaria is an example of a disease caused by protozoa.

Some groups of people may be more vulnerable to infection, for example because of age, or ill, or general health. If these groups become infected the symptoms may be serious and life-threatening. If the micro-organisms which cause the illness are resistant to antibiotics, it can be difficult to treat the illness.

Use to answer question 15.1a of the Care Certificate