Disease Transmission Flashcards
What are the 6 types of disease transmissions?
1) Contact - (indirect/direct); direct - touching an infected person (conjunctivitis). Indirect - contact with a fomite that contains the pathogen (tetanus).
2) Body Fluid - saliva, urine, semen, blood - breaks in skin/mucus membrane contact (HIV).
3) Airborne Droplet - droplets of moisture containing the pathogen from coughing, sneezing, etc. (influenza).
4) Ingestion - food/drink contaminated with pathogen from poor hygiene or lack of refrigeration (E. coli).
5) Vectors - transfer via. inverterbrate (insects - malaria).
6) Zoonotic - transfer via. vertebrate; animals such as rats, bats, etc. (anthrax).
What are pathogens?
Disease carrying organisms; disturbing normal bodily functions (bacteria/viruses).
What are the 2 main types of pathogens?
Bacteria - unicellular; classified according to cell shape. Has cytoplasm but no membrane bound organelles. Has DNA (plasmids) but no nucleus. Most are beneficial/harmless.
Virus - don’t have cells; can only reproduce inside the host cell. Smaller than bacteria. Contain RNA/DNA. Use host cell where RNA/DNA make more virus particles.
What is the difference between an priary/secondary/intermediate host and a vector?
Primary - host that provides food/shelter to the parasite in its maturing (sexually) stage.
Secondary - host occupied by a parasite in its larval/aexual state.
Intermediate - host infected by a parasite whilst in its development form; not sexually mature.
Vector - Any agent that carries and transmits parasites and diseases.
How may parasites benefit from vector transmission?
When they are unable to penetrate the celulose cell walls of plant cells.
Enabling the virus to penetrate the outer defecnces of its host.
