Symptoms range from mild to severe. The typical presentation of the disease varies as the disease progresses:
• During the first week, individuals usually present with a gradually increasing fever, and either constipation or diarrhea.
• By the second week, the fever usually persists. The individual may experience abdominal pain due to loose stools (usually yellow-green in color) or an inability to defecate. Rose-colored spots on the lower chest and abdomen may be seen; serious neurological complications (e.g. delirium, coma) may also arise at this stage.
• Further complications may occur by the third week, especially if the person does not receive treatment. These include bleeding and ulceration of the stomach and bowels, enlargement of the liver and spleen, and kidney damage.