6.2 emergence and re-emergence of pathogens

disease

condition in a living organism that impairs the normal functioning of an organ, part, structure or system

can be infectious or non-infectious

infectious

diseases that can be transmitted between individuals and are caused by pathogenic agents

• AIDS

• COVID-19

• Cholera

non-infectious

diseases that cannot spread from affected people via the environment

• genetic diseases

• cancer

• nutritional diseases

emerging diseases

diseases caused by a newly identified or previously unknown agent, or has existed in other species but whose incidence in humans has increased in the past two decades

• AIDS

• COVID-19

re-emerging diseases

diseases which reappear after a significant decline in its incidence, they were once controlled but have increased to a level that causes significant health issues

• cholera

• dengue

difference between a pandemic and an epidemic

pandemic: when many people worldwide contract a specific disease as it spread from a region of origin, in a relatively short time

epidemic: when many people in a community or restricted geographic area contract a specific disease at a particular time

how pathogens spread in a globally connected world

• people infected by pathogesn can transmit it to other people before they realise they are infected

• people are easily able to travel large distances quickly by car, train and plane

• animals may be vectors for the pathogen and some animals such as birds can fly long distances, carrying the pathogens between countries

• increased population densities offer large numbers of hosts accessible to pathogens

• healthcare workers in some countries may not have sufficient quarantine conditions to isolate sick patients from the community

impact of European arrival on Aboriginal and Torres Strait Islander peoples in terms of disease

• the Europeans had previously been exposed to the pathogens and had an immunity against it, so suffered minimal fatalities

• the A&TSI peoples had not been exposed previously and so had no immunological protection and low herd immunity, leading to a large number of fatalities