Caused by the bacteria salmonella typhi this disease is transmitted by milk, water or solid food which is contaminated by the faeces of a carrier. This carrier can be suffering from the effects of the disease or may just be a carrier and have no symptoms.
The period between infection and the start of symptoms is from one to three weeks. The bacteria collect in the small intestine and enter the bloodstream. After this the victim begins to experience the first symptoms, a chill followed by high fever. Headaches, severe cough, vomiting and diarrhoea are also common indications of infection.
In most cases the disease only lasts for a few weeks, after this period the person recovers. In 20% of untreated cases this does not occur and the disease progresses to pneumonia, internal intestinal haemorrhage and even death. In the 1940's an antibiotic was produced that has been successful in treating infected people, although this become less effective with new drug resistant strains.
The number of typhoid cases has been reducing due to tighter controls and improved sanitation. Inspection of water supplies and milk are good preventative measures, and the pasteurisation of milk has reduced the number of deaths from this disease.
It is also important to recognise people who carry the disease and prevent them from touching food or infecting water supplies. Vaccination of people exposed to the disease has also had a great impact.
