4.1. Communicable diseases

the different types of pathogen that can cause communicable diseases in plants and animals

tuberculosis

a disease that affects many parts of the body, killing the cells and tissues; the lungs are the most affected

caused by: bacteria

ring rot (in plants)

ring of decay in the vascular tissue of a potato tuber or tomato, accompanied by leaf wilting

caused by: bacterium

HIV/AIDS

attacks cells in the immune system and compromises the immune response

caused by: virus

influenza

attacks cells in the immune system and causes muscle pains and headaches

caused by: virus

tobacco mosaic virus

causes mottling and discolouration of leaves

caused by: virus

malaria

parasite in the blood that causes headache and fever and may progress to coma and death

caused by: protoctista

blight (potatoes and tomatoes)

affects both leaves and potato tubers

black sigatoka

causes leaf spots on banana plants reducing yield

caused by: fungus

athlete’s foot

growth of fungus in skin with spore cases erupting through skin to cause a rash

caused by: fungus

what is direct transmission?

passing a pathogen from host to new host with no intermediary

what is indirect transmission?

passing a pathogen from host to new host via a vector

what is transmission?

passing a pathogen from host to new host, via a vector

what is a vector?

an organism that carries a pathogen from one host to another