Fig. 4.1 is a simple outline of *V. cholerae*. Finish Fig. 4.1 by drawing and labelling the structures present in *V. cholerae*.
Calculate the case fatality rate for the 42 member countries of the WHA for 2015, and give your answer to the nearest 0.1%.
Of the 23 countries that reported cholera deaths in 2015, many had a case fatality rate below 1%. However, 2 of the 23 countries recorded case fatality rates above 5%. Suggest two explanations for the higher case fatality rate in these two countries.
In 2010, Haiti suffered a major earthquake. This caused a cholera outbreak. Explain why an earthquake may lead to a cholera outbreak.
Fig. 4.2 presents WHO data on cholera collected over an 8-year period from 2008 to 2015. The data show the total number of cholera cases in each year and the number of countries in each year that had cholera cases. Comment on the trends shown in Fig. 4.2.