Streptococcus bacteria can cause a sore throat or skin infection.

An illness called scarlet fever can also develop during an infection with this bacterium.

(a) (i) Give two precautions a doctor should take when treating a patient who is infected with Streptococcus.

(ii) From September 2013 to March 2014 there were 2830 cases of scarlet fever in the UK.

From September 2014 to March 2015 there were 5943 cases of scarlet fever.

Calculate the percentage increase of the number of cases of scarlet fever between the period September 2014 March 2015 and September 2013 to March 2014.