Transmission Of Pathogens

Question 1

What is direct transmission?

Answer 1

Passing a pathogen from host to new host, with no intermediary

Question 2

4 forms of direct transmission

Answer 2

Physical contact, faecel-oral transmission, droplet infection, spores.

Question 3

What is direct physical contact?

Answer 3

Person infected by touching contaminated surfaces that harbour pathogens. This is affected by; hygiene (washing hands, cleaning surface, cleaning cuts, using condoms, sterilising)

Question 4

What is faecal-oral transmission?

Answer 4

Eating or drinking something contaminated by pathogen. Using a sewage system to fertilise crops is common practice. Treatment of waste and water is important. Wash fresh food, cook food properly.

Question 5

What is droplet infection?

Answer 5

Pathogen is carried in tiny water droplets in the air. Prevented by catch it - bin it - kill it. Cover mouth when coughing and sneezing.

Question 6

What is transmission by spores?

Answer 6

Resistant stage of pathogen. Can be carried in the air or reside on surfaces or in the soil. Using a mask, washing skin prevents this form
occurring

Question 7

What is indirect transmission?

Answer 7

Passing a pathogen from host to new host, via a vector.

Question 8

Describe the transmission of malaria? (Virus with mosquito a vector) (7)

Answer 8

A person with malaria
Gametes of plasmodium in blood
Female anopheles mosquito sucks blood
Plasmodium develops and migrates to a mosquito's salivary glands
Uninfected person is bitten
Plasmodium migrates to liver 
Plasmodium migrates to blood (the end)

Question 9

How do plant pathogens transmit?

Answer 9

Spread by both indirect and direct.
Direct transmission– Many pathogens in soil snd will enter the roots – especially if these have been damaged due to replanting, burrowing animals or movement caused by a storm.
Many fungi produce spores as a means of sexual and asexual reproduction. Can be carried by wind - airborne transmission.
Indirect transmission– Occurs from insect attacks. Spores or bacteria can attach to burrowing insect like a beetle, attacks infected plant. When that same beetle attacks a healthy plant, it will transmit that virus or bacterium to the plant.

Question 10

How does disease and climate affect transmission of pathogens?

Answer 10

Bacteria and fungi can grow snd reproduce more rapidly in warm and moist conditions. Tend to be common in warmer climates. Colder climates,
These pathogens can be damaged by cold conditions. It may affect their ability to grow and reproduce. This means there is a greater variety of diseases to be found in a warmer condition. This means chance of infection is higher.