After they enter the intestinal wall, they survive in macrophages, which are white blood cells that swallow the typhoid bacilli. They are then disseminated to several organs through the bloodstream. There is a secondary phase where the typhoid bacilli enter the blood stream to cause the clinical symptoms of typhoid. They are also excreted in the urine and faeces. The incubation period for the disease varies from five to twenty-one days depending on the number of bacteria ingested.
Fever is a classical sign.
Only 20 to 40 percent of patients will have abdominal pain at presentation. A few patients develop diarrhoea also. Non-specific symptoms such as chills, sweating, headache, loss of appetite, weakness, sore throat and muscle pains are often present. Psychosis and confusion occur in 5 to 10 percent of patients. Coma is a rare complication.