4.3.1.1 Communicable (infectious) diseases

communicable

can be spread from person to person eg measles- infectious

non communicable disease

cannot be passed from person to person eg coronary heart disese

health

state of physical and mental state of wellbeing

what are pathogens

disease causing microorganisms

pathogens may be

viruses, bacteria, protists and fungi,

defective immune system

more likely to suffer from infectious diseases

infection from one disease can cause another

ways pathogens are spread

direct contact
air
water
food
animals

Direct contact

* touching contaminated surfaces
Examples: kissing, contact with bodily fluids, direct skin to skin, microorganisms
from faeces, infected plant material left in field
* HIV

water

* drinking or coming into contact with dirty water
* Cholera

air

* influenza
* pathogens can be carried in the air and then breathed in
(a common
example is the droplet infection, which is when sneezing, coughing or talking
expels pathogens in droplets which can be breathed in)

food

can harmful microbes in it eg salmonella

Viruses

● Very small

cannot reproduce

by themselves

● They move into cells and use the biochemistry of it to make many copies of itself

● This leads to the cell bursting and releasing all of the copies into the bloodstream

● The damage and the destruction of the cells makes the individual feel ill

Bacteria

● Small

● They multiply very quickly through dividing by a process called binary fission

● They produce toxins that can damage cells an tissues

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Protists

Some are parasitic, meaning they use humans and animals as their hosts
(live on and inside, causing damage)

Fungi

● They can either be single celled or have a body made of hyphae (thread-like
structures)
● They can produce spores which can be spread to other organisms

how to limit spread of pathogens

● Improving hygiene: Hand washing, using disinfectants, isolating raw meat, using
tissues and handkerchiefs when sneezing
● Reducing contact with infected individuals
● Removing vectors: Using pesticides or insecticides and removing their habitat
● Vaccination: By injecting a small amount of a harmless pathogen into an individual’s
body, they can become immune to it so it will not infect them. This means they
cannot pass it on.

provide clean water

iscolate

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Good health

a state of complete physical, mental, and social well-being and not merely the absence of disease or infirmity.

factors that contribute to good or poor health...

dieseases

Diet

​ Exercise

​ Stress levels​

Where you live​

Gender​

Financial status

​ Ethnic group​

Access to free health care​

How many children you have​ Sewage and rubbish disposal systems locally​