1.1. Typhoid is a communicable disease caused by the bacterium Salmonella typhi.

(i) Bacteria are a type of pathogen.

Name one other type of pathogen.

(1)

(ii) Typhoid is spread through contaminated water and food.

Suggest why typhoid is more prevalent in developing countries.

(2)

1.2. The graph in Figure 1 shows the number of cases of typhoid and monthly rainfall in Dhaka, Bangladesh. It is estimated that there are around 4 million people living in deprived urban areas in Dhaka.

(i) Suggest an explanation for the pattern shown in the graph in Figure 1.

Figure 1

(2)

(ii) In the UK, typhoid vaccination is offered to people travelling to parts of the world where the condition is common. 

Explain why tourists in Bangladesh who have been vaccinated would not develop typhoid even if they become infected with the typhoid pathogen by drinking contaminated water.

(3)