Non-bacterial Pathogens- Topic 6 Flashcards
How are the different species of influenza virus classed?
Differences in haemagglutinin and neuraminidase
Mode of transmission of influenza
Droplet, direct contact, indirect contact, air
What genetic material does influenza have?
RNA
What is a zoonotic infection and what is it likely to cause?
Crosses the species barrier- pandemic
Mode of infection- influenza
Cilliated epithelial cells- lysis of cells cause symptoms of disease
What is the danger of having damaged cells from influenza?
Secondary infection
Why is it important to vaccinate against influenza annually?
Because RNA is more prone to mutation
What is the antigenic shift and what is the effect of this?
Genetic reassortment of the virus that results in a unique change- no one has immunity so prone to pandemic
What is antigenic drift?
Point mutation of haemagglutinin/ neuraminidase gene results in slight alteration- some immunity
Mode of infection- stem rust fungus
- spores land on host and use water to germinate
- asexual
- hyphae grows into the plant secreting enzymes to absorb nutrients
- hyphae forms a mycelium hidden in the stem or leaves
- teliospires affect Berberis
Mode of transmission- stem rust fungus- what does pattern show?
- spores carried by wind
- pattern of infection helps determine if source is local or distant (broad)
Pathogenic effect of stem rust
Red pustules break through epidermis which contain spores
- absorbs nutrients from plant
- epidermis breaks-plant cannot control transpiration- entry to other pathogens- dry out
- mycelium grows into vascular tissue absorbing plants water
- weakens stem
How can stem rust be controlled?
- increase spaces between crops= reduce moisture and increase distance the spore needs to travel
- reduce fertilisers as nitrates help rust
- use earlier maturing crops to beat rust life cycle
- remove wild berberis to interrupt life cycle
- fungicides
What is malaria?
Protozoa- single celled organisms spread by anopheles female mosquitos (vector)
Mode of infection- malaria
Parasite travels to liver- invades RBC and reproduces asexually- lysis of RBC- gametes infect mosquito
Problems with malaria being endemic
- widespread
- pathogen widespread- difficult to remove sources of infection
- requires co-operation of population
- costs a lot as many people are involved
Pathogenic effect of malaria
- flu like symptoms cause by bodies response to RBC lysis
- liver damage
- reduction in RBC= anaemia and weakness
- worse if have a pre existing condition eg HIV
Why is treatment of malaria difficult?
Parasite hides from immune system in bodies cells
Treatment of malaria
Quinine and chloroquinine- need to be given soon after infection- limitation of resistance building
-anti malarial medicine- given to anyone travelling to infected countries
Preventing malaria
Vaccine gives temporary protection
Mosquito nets sprayed in insecticide
Controlling mosquitos
Education
Preventing parasitic breeding
Remove breeding sites
Dispose of sewage
Biological control- ensure breeding grounds contain mosquito eating predators
Chemical control- pesticides- however may endanger other biodiversity
Social implications with preventing malaria
Persuading people to change social behaviour
Economic implications of preventing malaria
If treatments are temporary is spending money worth the gain? Are there other areas it should be spent?
Ethical implications of preventing malaria
Can everyone consent? Will insecticide kill other animals?
How can we avoid overuse of expensive drugs in treating malaria?
Diagnosis- View parasite in the blood
How to over come resistance in treating malaria
Different combinations
