chapter 6: disease challenge and strategies Flashcards
difference between emerging and re-emerging pathogens
- examples of each
emerging (new)
- a disease caused by a newly identified or previously unknown agent
- e.g. covid-19
re-emerging (coming back)
- a disease which reappears after a significant decline in its incidence
- re-emerging diseases were once controlled but have increased to a level that causes significant health issues
- e.g. monkey pox
define infectious disease
infectious diseases are transmitted from person to person through the transfer of a pathogen such as bacteria, viruses, fungi or parasites
difference between an epidemic and a pandemic
epidemic:
- widespread infectious disease in an area at a particular time
- a concern is that the disease may spread more widely and become a pandemic
pandemic:
- global outbreak of a disease
- it affects a high proportion of the population
- uncontrolled spread of the pathogen occurs across a wide geographic area
- community level outbreaks in at least two WHO regions
state the impact of European (infectious disease) arrival on Indigenous populations
European arrival caused epidemics for Aboriginal and Torres Strait Islander peoples
- prior to European arrival there was little interaction between Indigenous peoples and Europeans
- after settlement, they brought various new diseases and pathogens to populations that had no prior exposure
- through this, it places a burden on their overall health and population –> decreases their population
explain why diseases introduced by Europeans had such a large impact on Indigenous Australians
western diseases were unknown in the Indigenous population
- Indigenous populations had no immunity against them
- large numbers of susceptible individuals –> results in low herd immunity
- rapid spread of new infectious diseases and significant fatalities
describe physical methods to identify pathogens
physical methods can assist in identifying viruses based on size and shape
x-ray crystallography
- which has determined the structure of many viruses
electron microscopy
- which had given us images that distinguish various kinds of viruses
describe immunological methods to identify pathogens
immunological methods detect specific viral antigens of antibodies which allowed for the diagnosis of diseases
ELISA
- a plate has antibodies attached on the test line
- conjugated antibodies are free to move
- when the conjugated antibodies bind to their specific antigen and the attached antibodies, a colour is observed —> indicted a positive test
describe how pathogens can be transmitted between individuals
- airborne
- respiratory (droplets)
- food and water
- sexually
- animal and insect
- health care
describe control measures to prevent or limit the spread of infectious disease
- prevention – clean water, wash hands, safe sex, etc.
- vaccination – reduce the number of hosts
- medication – treat people to reduce transmission
- surveillance – monitor outbreaks to act
- modification of environment – drain ponds, mosquito nets
- improving infection control standards – sterilisation of surfaces/objects, masks, quarantine, etc.
explain why identifying the host or reservoir is important in controlling the spread
- they can also be used to help identify the correct treatment to be given to an infected
- help enable preventative measures
describe 3 ways that antibiotics work
- inhibition of cell wall synthesis –> stops cell wall from being produced
- inhibition of protein synthesis –> stops bacteria from making proteins
- cause injury to the plasma membrane
describe 3 ways that antivirals work
antivirals only act on viruses actively replicating
- block entry of the virus into host cells
- block fusion of virus with host cells
- block uncoating
- prevent replication of the viral genome
- prevent releases of new viruses
- stimulate host immune system
- stops the virus from replicating
why are antibiotics not effective in treating viral infections
viral infections happen inside of the cell, so antibodies won’t be able to get rid of the cell but rather inactivate it.
- it is also not effective because antibodies can’t reach the inside of the cell, just the outside.
what is in a vaccine
vaccines are substances that cause an immune response (active, artificial immunity)
- vaccines work because your immune system makes antibodies and memory cells (specific to the pathogen injected with)
they can be pathogens that are:
- live attenuated
- inactivate
- toxoin of bacteria
- subunits of bacteria or viruses
explain how vaccines provide long-term immunity
- memory cells remember the pathogen that has entered your body
- if a pathogen enters the body, the body would already have an immune response against it because of the memory cells
