U4 AOS1 Topic 6: Emergence of Pathogens

A disease can either be infectious or non-infectious. Infectious diseases are caused by pathogens whereas non-infectious diseases are not caused by pathogens instead these are caused by abnormal genes or by lifestyle factors. Infectious diseases which are caused by pathogens and spread between people are known as contagious diseases.

A pathogen which causes infectious disease can be called contagious depending on how easily it can be transmitted whereas, a pathogen can be called virulent depending on how severe disease it can cause.

Emerging disease: an infectious disease that has occurred for the first time in a population or has been recognized recently.

Re-emerging disease: an infectious disease that was recognized once in a population but was under control and has now re-emerged in a population.

Factors affecting the emergence and re-emergence of the disease

1.   The pathogen which causes disease can evolve or become resistant to treatment.

2.    People travelling around the world can quickly spread the disease.

3.   Zoonosis causes disease to transmit from animals or other species to humans.

4.   Increased population can cause increased spread of disease.

5.   Technology can also spread disease. For example, some pathogens may inhabit air conditioners.

6.   Insufficient vaccination can cause previously emerged disease to re-emerge.

Emerging and re-emerging diseases can spread to a large group of people causing an outbreak or sudden increase in occurrence of disease. An outbreak can be an epidemic or pandemic.

·        An epidemic is a sudden outbreak of a disease in a specific population.

·        Pandemic is a sudden outbreak of a disease that can spread in different countries.

                

Impact of European arrival on indigenous people of Australia

Pathogens introduced into Australia by European arrival can affect the indigenous people of Australia more because of following factors:

1.   A lack of immunity in Australian local population as they don’t have innate natural immunity against disease introduced by European arrival.

2.   Indigenous people of Australia have no awareness to control the new diseases introduced into the population by Europeans.

3.   The arrival of Europeans causes increased population density and greater chance of spread of diseases in indigenous people of Australia.