TYPHOID is an infection caused by Salmonella typhimurium bacteria that is spread from human to human. The Salmonella typhimurium (S. typhi) is related to the bacteria that causes food poisoning. Typhoid is highly contagious. An infected person can pass the bacteria out of their stool or less commonly in their urine. If someone also eats food or drinks water that is been contaminated with amount of infected stool or urine, they can become infected with the bacteria and develop typhoid fever. Again, S typhi enters through the mouth and spreads 1 to 3 weeks in the intestines. After this, it makes its way through the intestinal wall and into the blood stream. From the blood stream it spreads to other tissues and organs. The immune system of the host can do little to fight back because S. typhi can live within the host's cell, safe from the immune system. SYMPTOMS Symptoms start to manifest between 6 and 30 days of exposure to the bacteria. They are: √ Cough √ Headache √ Constipation √ Vomiting √ Difficulty in paying attention √ Cold and chills √ Abdominal pain, and so on.