Unit 12: Diseases and Infection
B: Examine the transmission of infectious diseases and how this can be prevented
Assignment B P3 + M2
Infectious diseases can spread in a variety of ways: through the air, from direct or indirect
contact with another person, soiled objects, skin or mucous membrane, saliva, urine,
blood and body secretions, through sexual contact, and through contaminated food and
water.
Spread through the air by droplets
Some infections are spread when an infected person talks, coughs or sneezes small
droplets containing infectious agents into the air. Due to their size, these droplets in the
air travel only a short distance (around a metre) from the infected person before falling.
The droplets in the air may be breathed in by those nearby. Spread can also occur by
touching the nose or mouth with droplet contaminated hands.
Examples of droplet spread diseases: common cold, flu, meningococcal disease, rubella.
Spread through the air by aerosol
Some infections are spread when an infected person talks, breathes, coughs or sneezes
tiny particles containing infectious agents into the air. These are called small particle
aerosols. Due to their tiny size, small particle aerosols can travel long distances on air
currents and remain suspended in the air for minutes to hours. These small particle
aerosols may be breathed in by another person.
Examples of airborne spread diseases: chickenpox, measles, tuberculosis (TB).
Spread through faeces and then the mouth (faecal-oral spread)
Some infections are spread when microscopic amounts of faeces (poo) from an infected
person with symptoms or an infected person without symptoms (a carrier) are taken in by
another person by mouth. The faeces may be passed:
- directly from soiled hands to the mouth
- indirectly by way of objects, surfaces, food or water soiled with faeces.
B: Examine the transmission of infectious diseases and how this can be prevented
Assignment B P3 + M2
Infectious diseases can spread in a variety of ways: through the air, from direct or indirect
contact with another person, soiled objects, skin or mucous membrane, saliva, urine,
blood and body secretions, through sexual contact, and through contaminated food and
water.
Spread through the air by droplets
Some infections are spread when an infected person talks, coughs or sneezes small
droplets containing infectious agents into the air. Due to their size, these droplets in the
air travel only a short distance (around a metre) from the infected person before falling.
The droplets in the air may be breathed in by those nearby. Spread can also occur by
touching the nose or mouth with droplet contaminated hands.
Examples of droplet spread diseases: common cold, flu, meningococcal disease, rubella.
Spread through the air by aerosol
Some infections are spread when an infected person talks, breathes, coughs or sneezes
tiny particles containing infectious agents into the air. These are called small particle
aerosols. Due to their tiny size, small particle aerosols can travel long distances on air
currents and remain suspended in the air for minutes to hours. These small particle
aerosols may be breathed in by another person.
Examples of airborne spread diseases: chickenpox, measles, tuberculosis (TB).
Spread through faeces and then the mouth (faecal-oral spread)
Some infections are spread when microscopic amounts of faeces (poo) from an infected
person with symptoms or an infected person without symptoms (a carrier) are taken in by
another person by mouth. The faeces may be passed:
- directly from soiled hands to the mouth
- indirectly by way of objects, surfaces, food or water soiled with faeces.
