Explain why washing hands regularly reduces the risk of spreading communicable diseases.
Written & reviewed by James Millett — Biology (Imperial College London), PGCE Science (University of Cambridge).
During a norovirus outbreak in a school, health officials advised all students and staff to wash their hands thoroughly with soap and water, especially after using the toilet and before eating.
Model answer (4 marks)
Pathogens such as bacteria and viruses can be carried on the skin of the hands.
When a person touches a contaminated surface and then touches their mouth, food or mucous membranes, the pathogens can be transferred and enter the body.
Washing hands with soap and water removes the pathogens from the skin and the mechanical action of rubbing, together with the detergent, can also kill many of them.
By removing or killing the pathogens, the hands are no longer a vehicle for transmission, so the chance of passing the disease to another person is greatly reduced, preventing the spread of the communicable disease.
When a person touches a contaminated surface and then touches their mouth, food or mucous membranes, the pathogens can be transferred and enter the body.
Washing hands with soap and water removes the pathogens from the skin and the mechanical action of rubbing, together with the detergent, can also kill many of them.
By removing or killing the pathogens, the hands are no longer a vehicle for transmission, so the chance of passing the disease to another person is greatly reduced, preventing the spread of the communicable disease.
Examiner tips
- Use the exact wording from the mark scheme – mention pathogens, transfer, removal/kill, and reduced spread.
- Show the logical sequence: presence → transfer → removal → prevention.
- Keep each point concise and separate with a line break or bullet.
Common mistakes
- Failing to mention that pathogens can be on the hands; only talking about surfaces. Using vague phrases like "clean hands" without explaining removal or killing of pathogens. Omitting the final point that reduced spread prevents communicable disease.
Mark scheme (4 marks)
- Pathogens (such as bacteria/viruses) can be present on the hands / skin surface
- Pathogens can be transferred from hands to the mouth / food / mucous membranes, allowing entry into the body
- Washing hands removes / kills pathogens from the hands
- This reduces the chance of pathogens being passed to another person / prevents spread of infection (communicable disease)
Key terms in this question
Related
- Revision notes: Communicable diseases →
- How to answer a "Explain" question →
- Decode the mark scheme abbreviations →
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