Transmission of Communicable Diseases

Question 1

What are the 5 different ways pathogens can be transmitted to animals

Answer 1

• direct contact
• inoculation
• fomites
• droplet infection (inhalation)
• vectors

Question 2

What is inoculation in the transmission of communicable diseases to animals

Answer 2

• through a break in the skin
  E.g. HIV/AIDS
• from an animal bite e.g. rabies
• through a puncture wound e.g. sharing needles causing septicaemia

Question 3

What is fomites in the transmission of communicable diseases to animals

Answer 3

• inanimate objects e.g. bedding , socks causing athletes foot

Question 4

What is droplet infection in the transmission of communicable diseases to animals

Answer 4

• minute droplets of saliva that are expelled as you talk, sneeze or cough e.g. tuberculosis, influenza

Question 5

What is a vector in the transmission of communicable diseases to animals

Answer 5

• when a communicable pathogen is passed from one host to another usually by an animal
• e.g. rat fleas - bubonic plague
• mosquitoes - malaria
• dogs and foxes - rabies
• water can also act as a vector

Question 6

What are the 6 factors that will increase the probability of catching a communicable disease in animals

Answer 6

• overcrowded living and working conditions
• Poor nutrition
• Compromised immune system
• poor disposal of waste
• Climate change - can introduce vectors to new diseases
• Culture and infrastructure - i many countries traditional medical practices can create infection
• Socio-economic factors

Question 7

What are the 4 different ways pathogens can be transported and infect plants with a communicable disease

Answer 7

• Direct contact
• Soil contamination
• Wind
• Water

Question 8

What is direct contact in the transmission of communicable diseases in plants
And an example of diseases that are transmitted in this way

Answer 8

• direct touching of a healthy plant with any part of a diseased plant

E.g. ring rot, TMV, tomato and potato blight, black Sigatoka

Question 9

What is soil contamination in the transmission of communicable diseases in plants
And an example of diseases that are transmitted in this way

Answer 9

• Infected plants leave bacteria/ viruses or reproductive spores from protoctist a or fungi in the soil. These can infect the next crop.

E.g. black Sigatoka spores, ring rot bacteria, spores of TMV

Question 10

What is wind in the transmission of communicable diseases in plants
And an example of diseases that are transmitted in this way

Answer 10

• bacteria, viruses and fungal or oomycete spores may be carried in the wind

E.g. black sigatoka blown across Caribbean islands

Question 11

What is water in the transmission of communicable diseases in plants
And an example of diseases that are transmitted in this way

Answer 11

• Spores swim in the surface film of water on leaves: raindrops carry pathogens/ spores

E.g. potato blight spores swim over films in leaves

Question 12

What are the 5 factors that will affect the transmission of communicable diseases among plants

Answer 12

• Planting varieties of crops that are susceptible to disease
• overcrowding increases the likelihood of contact
• Poor mineral nutrition reduces resistance of plants
• Damp, warm conditions increases the survival and spread of pathogens and spores
• climate change - increased rainfall and wind promote the spread of disease