2021TrialShort answer

Q24

3 marks

Question

Giardiasis is the most common form of non-bacterial diarrhoea of people in Australia. The adult parasite, Giardia lamblia, responsible for the disease, is shown in the figure below. The adult is a single cell. Its ventral side is flattened and has a shallow depression used as a type of sucker. Giardia lives in the upper part of the intestine (duodenum) of an infected person where it rapidly multiplies. To pass from one human to another it encloses itself in a cyst that passes out in the faeces.
Describe ONE procedure that would be suitable for preventing the spread of Giardia and justify its use.

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Solution

Criteria	Marks
• ONE Detailed procedure.<br>• Explanation to support.	3
• Procedure outlined with some detail missing	2
• Some relevant information	1

Sample answer:

To pass from one human to another it encloses itself in a cyst that passes out in the faeces, these cysts contaminate the food or drink of other humans. Thoroughly washing hands with soap, water and drying them after using the toilet or before preparing food removes the pathogen and prevents contamination of food to stop transmission by the faecal-oral route. Comments: Remember if a question states ‘ONE’, then the answer should have ONE. (The first will be marked, any others will not. In the case of contradictions marks will be lost). Be careful that your ONE procedure doesn't flow into others. Best would be hand washing after toilet use for this pathogen. (e.g. some people stated hand washing after or before food prep.) ‘Hygiene and sanitation’ could include a lot of things. – cleaning the toilet, hand washing, sanitising hard surfaces/door handles, brushing teeth, bathing. Be distinct and clear. Sewage water is not used for drinking/washing/cooking. Treatment and management of sewage water is appropriate for minimising the spread of diseases but not because we drink it. Range 0-3 Avg. 2.67

Supplied marking guidance · human reviewed

Compare this with your working, not only your final sentence.

Syllabus alignment

Module 7 · Infectious Disease

Causes of Infectious DiseaseInvestigate direct-contact, indirect-contact and vector transmission.
Prevention, Treatment and ControlInvestigate prevention through hygiene, quarantine, vaccination, campaigns, pesticides and genetic engineering.

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