MODULE 7 - infectious disease
Inquiry question 1 - how are diseases transmitted?
Describe a variety of infectious diseases caused by pathogens, including microorganisms, macroorganisms and non cellular pathogens and
collect primary and secondary sourced data and information relating to disease transmission including
Classifying different pathogens that cause disease in plants and animals
Term Definition
Disease Any condition that impairs the normal living processes and is recognised by specific symptoms
Infection The presence of a disease causing organism in or on the body of the host
Host Any organism that carries another organism or agent
Infectious disease A disease that is caused by a pathogen or infectious agent and the disease can be transmitted from one organism to
another.
Non infectious disease A disease that is not caused by a pathogen and is unable to be passed from one organism to another
Pathogen An infectious agent that is capable causing a disease in a host
Macroorganism Pathogens visible with the naked eye
Microorganism Pathogens that are not visible with the naked eye
Cellular pathogens Pathogens that have cell structure and can often reproduce on their own
Non cellular pathogens Pathogens that exist without a cell structure and require host cells to reproduce
Transmission When a pathogen is passed from one infected organism to another organism either directly or indirectly.
,Virulence A measure of the serenity of the disease a pathogen causes
Direct contact Transmission occurs when there is physical contact between an infected organism and a susceptible one.
Indirect contact Transmission of an infectious disease by touching contaminated objects or coming in contact with pathogens that are in
the air or water
Vectors Organisms that do not cause disease themselves but transmit infectious disease by transporting pathogens from one
organism to another
Dormancy A state in which an organism such as a pathogen remains inactive or in a resting phase for a period of time
Reservoir Any living organism or non living environment that naturally harbors a pathogen and serves as a source of infection for
other hosts.
Active carrier An individual who is infected with a pathogen and shows symptoms and can transmit the disease to others.
Passive carrier An individual who harbors a pathogen without being infected themselves and call transmit it to others, often through
contaminated hands and surfaces.
Asymptomatic carrier An individual who is infected with a pathogen but does not show symptoms, yet can still spread the disease to others.
Host An organism that provides a suitable environment for a pathogen to live, grow and reproduce often suffering harm.
Fomite An object that becomes contaminated with pathogens
Vehicle transmission Pathogens being transferred between individuals and the environment within a substance such as soil, air, water or food
Vector transmission Pathogens being transferred between individuals either on or inside living organisms
Endemic Usual presence of a disease within a given population
Epidemic Occurrence of a disease clearly in excess of normal expectancy in a defined community or region
,Pandemic Worldwide epidemic
, Classifying pathogens in plants and animals
Pathogen Classification Description Examples
Prion Microscopic non ● Abnormally folded protein which multiplies → Creutzfeldt-
cellular by transmitting misfolded proteins to other Jakob Disease is caused by the prion pathogen
cellular proteins = impairs their function
● Do NOT contain DNA or RNA
● Smallest pathogen
● Proteinaceous infectious particles
Virus Microscopic non ● Consists of nucleic acid (DNA or RNA) inside a → Zaire ebolavirus is the pathogen that causes
cellular protein coat (envelope) Ebola virus disease
● Replicates inside living cells → Sars-Cov-2 causes the disease coronavirus
Bacteria Microscopic cellular ● Single celled prokaryotic organism (no Salmonella
membrane bound organelles)
● Reproduce by binary fission
● Secrete toxins, invade cells, and form colonies
(biofilms) which disrupt cell functions.
Inquiry question 1 - how are diseases transmitted?
Describe a variety of infectious diseases caused by pathogens, including microorganisms, macroorganisms and non cellular pathogens and
collect primary and secondary sourced data and information relating to disease transmission including
Classifying different pathogens that cause disease in plants and animals
Term Definition
Disease Any condition that impairs the normal living processes and is recognised by specific symptoms
Infection The presence of a disease causing organism in or on the body of the host
Host Any organism that carries another organism or agent
Infectious disease A disease that is caused by a pathogen or infectious agent and the disease can be transmitted from one organism to
another.
Non infectious disease A disease that is not caused by a pathogen and is unable to be passed from one organism to another
Pathogen An infectious agent that is capable causing a disease in a host
Macroorganism Pathogens visible with the naked eye
Microorganism Pathogens that are not visible with the naked eye
Cellular pathogens Pathogens that have cell structure and can often reproduce on their own
Non cellular pathogens Pathogens that exist without a cell structure and require host cells to reproduce
Transmission When a pathogen is passed from one infected organism to another organism either directly or indirectly.
,Virulence A measure of the serenity of the disease a pathogen causes
Direct contact Transmission occurs when there is physical contact between an infected organism and a susceptible one.
Indirect contact Transmission of an infectious disease by touching contaminated objects or coming in contact with pathogens that are in
the air or water
Vectors Organisms that do not cause disease themselves but transmit infectious disease by transporting pathogens from one
organism to another
Dormancy A state in which an organism such as a pathogen remains inactive or in a resting phase for a period of time
Reservoir Any living organism or non living environment that naturally harbors a pathogen and serves as a source of infection for
other hosts.
Active carrier An individual who is infected with a pathogen and shows symptoms and can transmit the disease to others.
Passive carrier An individual who harbors a pathogen without being infected themselves and call transmit it to others, often through
contaminated hands and surfaces.
Asymptomatic carrier An individual who is infected with a pathogen but does not show symptoms, yet can still spread the disease to others.
Host An organism that provides a suitable environment for a pathogen to live, grow and reproduce often suffering harm.
Fomite An object that becomes contaminated with pathogens
Vehicle transmission Pathogens being transferred between individuals and the environment within a substance such as soil, air, water or food
Vector transmission Pathogens being transferred between individuals either on or inside living organisms
Endemic Usual presence of a disease within a given population
Epidemic Occurrence of a disease clearly in excess of normal expectancy in a defined community or region
,Pandemic Worldwide epidemic
, Classifying pathogens in plants and animals
Pathogen Classification Description Examples
Prion Microscopic non ● Abnormally folded protein which multiplies → Creutzfeldt-
cellular by transmitting misfolded proteins to other Jakob Disease is caused by the prion pathogen
cellular proteins = impairs their function
● Do NOT contain DNA or RNA
● Smallest pathogen
● Proteinaceous infectious particles
Virus Microscopic non ● Consists of nucleic acid (DNA or RNA) inside a → Zaire ebolavirus is the pathogen that causes
cellular protein coat (envelope) Ebola virus disease
● Replicates inside living cells → Sars-Cov-2 causes the disease coronavirus
Bacteria Microscopic cellular ● Single celled prokaryotic organism (no Salmonella
membrane bound organelles)
● Reproduce by binary fission
● Secrete toxins, invade cells, and form colonies
(biofilms) which disrupt cell functions.
