biology communicable diseases

pathogen

A microorganism that causes disease

health

a state of being healthy. A person's mental and physical health.

communicable diseases

they are transmitted from one person to another. They are also known as infectious disease.

cause of communicable diseses

pathogens

how pathogens make us ill

some bacteria produces toxins.

p

bacteria can multiply rapidly and damage the cells.

how do pathogens spread

water, air, direct contact and blood.

air

coughing, sneezing, talking, spores on a breeze.

air examples

tuberculosis, influenza, cold

direct contact

sexually transmitted cuts, scratches via vectors. common in plants.

direct contact examples

HIV, chlamydia, hepatitis

water

fungal spores in splashing water, water contaminated with faecal matter.

water examples

cholera, salmonella

Lister

made vaccines for anthrax and rabies.

measles transmission

droplet (m)

measles prevention

vaccination, improvement to living conditions.

measles treatment

isolation to prevent spread.

HIV transmission

sexual contact, exchange of body fluids.

HIV prevention

using protection and not sharing needles.

HIV treatment

no cure. antiretrovial drugs can slow it down

salmonella transmission

eating under cooked, unhygenically prepared food.

salmonella prevention

keeping raw and cooked meat separate. cook properly, keep surfaces clean.

salmonella treatment

none, usually symptoms go within a few days.

gonorrhoea transmission

direct sexual contact.

gonorrhoea prevention

barrier methods of contraception.

gonorrhoea treatment

antibiotics such as penicillin.

malaria step 1

female anopheles mosquito takes a blood mean from a human and injects saliva containing malarial protists into the blood.

malaria step 2

malaria travels to the liver and reproduces.

malaria step 3

the malaria breaks out of the liver and infects the blood cells.

malaria step 4

as it spreads, it bursts the red blood cells causing the symptoms seen in the disease.

malaria step 5

another mosquito takes a blood meal from the infected person.

malaria step 6

the protist reproduces in the mosquito and ends up in its saliva.

How white blood cells fight infection

release antibodies that break the organism down and destroy it.

More white blood cells

Some white blood cells produce antitoxins which cancel out the toxins released by the pathogen.