Typhoid fever is an infectious feverish disease with severe symptoms in the digestive system in the second phase of the illness. Classic typhoid fever is a serious disease. It can be life-threatening, but antibiotics are an effective treatment. The disease lasts several weeks and convalescence takes some time.

The disease is transmitted from human to human via food or drinking water, and it is therefore mainly hygiene and sanitary conditions that determine its spread.

The incubation period is 10 to 20 days and depends on, among other things, how large a dose of bacteria has been taken in.

In the mild disease, the bacterium is eliminated very early in the course of the disease and there are perhaps only mild symptoms. It is possible to become a healthy carrier of infection.

There are two phases of classic typhoid fever:

• 1st phase: the patient's temperature rises gradually to 40ºC and the general condition becomes very poor with bouts of sweating, no appetite, coughing and headache. Constipation and skin symptoms may be the clearest symptoms. Children often vomit and have diarrhoea. The first phase lasts a week and towards the end the patient shows increasing listlessness and clouding of consciousness.
• 2nd phase: in the second to third weeks of the disease, symptoms of intestinal infection are manifested and the fever remains very high and the pulse becomes weak and rapid. In the third week the constipation is replaced by severe pea-soup-like diarrhoea. The faeces may also contain blood. It is not until the fourth or fifth week that the fever drops and the general condition slowly improves.