1. 1
   A doctor is investigating the case of a six-year-old child who has a high fever and a red rash covering the skin. The child has not received the routine childhood vaccination. Blood tests confirm the child is infected with a pathogen.

   (a)

   Which type of pathogen has most likely caused this child's illness?

   [1 mark]

   • AA bacterium
   • BA protist
   • CA virus
   • DA fungus

   (b)

   How is the pathogen causing this child's illness most likely to have been spread to the child?

   [1 mark]

   • ADirect contact with a contaminated wound
   • BIngestion of contaminated food
   • CA mosquito bite
   • DInhalation of droplets from coughs and sneezes

   (c)

   Explain how vaccination could have prevented this child's illness.

   [2 marks]

   Total for question 1: 4 marks

2. 2
   Following a wedding reception, several guests who ate chicken curry prepared in a kitchen with poor hygiene standards developed a fever, abdominal cramps, vomiting and diarrhoea within 24 hours. Environmental health officers confirmed bacterial contamination of the food.

   (a)

   Which pathogen most likely caused this outbreak?

   [1 mark]

   • AMalaria protist
   • BInfluenza virus
   • CSalmonella bacterium
   • DRose black spot fungus

   (b)

   What is the main way in which the disease was spread to the guests in this scenario?

   [1 mark]

   • AInhalation of airborne droplets
   • BSexual contact
   • CIngestion of contaminated food
   • DA vector such as a mosquito

   (c)

   Explain why the guests developed these symptoms after eating the contaminated food.

   [2 marks]

   Total for question 2: 4 marks

3. 3
   A public health team is working in a region near a large lake where mosquitoes breed in the still water. Many villagers experience recurring episodes of high fever, and blood samples reveal that a protist pathogen, transmitted between people by mosquito bites, is present in the affected population.

   (a)

   Name the disease affecting the villagers and identify the type of pathogen responsible.

   [3 marks]

   (b)

   Suggest two ways in which the spread of this disease could be controlled in the village, and explain how each method reduces transmission.

   [4 marks]

   Total for question 3: 7 marks

4. 4
   A pharmaceutical company has developed a new antibiotic-based medicine to treat a bacterial infection that has become increasingly resistant to existing antibiotics. Before the medicine can be prescribed, it must go through preclinical testing and then clinical trials, including double-blind trials involving patients.

   (a)

   Explain the stages that this new antibiotic-based medicine must go through before it can be prescribed to patients, and explain why each stage is necessary.

   [6 marks]

   (b)

   Explain why bacteria are becoming resistant to antibiotics, and evaluate why this makes treating this bacterial infection more difficult.

   [6 marks]

   Total for question 4: 12 marks

End of questions