The bacteria can be introduced in the human body from contaminated food or water. Most bacteria will be killed when it reaches the stomach, due to the high acidity of the gastric juice. When enough bacteria eventually could pass the gastric barrier, it resides in the bile, and then it reaches the intestines. In the bowels it will infect the inside lining of the intestines causing small wounds and some bacteria will be excreted in the stool, thus with bad hygiene of a food handler shedding S. typhi or if sewage contaminated with S. typhi bacteria gets into the water used for drinking or washing food, the bacteria will be transferred to another host.
Within 3 to 60 days, the person infected will show symptoms. The disease classically presents with a step-like daily increase in temperature associated with headache, feeling week, and chills. Early intestinal manifestations include constipation (especially in adults) or mild diarrhea (especially in children).
The definite diagnosis of typhoid fever is isolating the S. typhi from a culture test. However, this test is time consuming and costly, so in addition some medical centres would also perform a simpler and faster test, the Widal test, though it is less specific.
The treatment is with antibiotic, usually a 2 week course. Patients are also advised to rest and have a low fibre diet to rest the infected intestines. Once the diagnosis of typhoid fever is made, it is important to follow the doctor’s recommendations. Untreated or under-treated typhoid may lead to serious complications, especially to the intestines. At early stage it will cause small wounds inside the intestines, with time these wounds can become larger and deeper, eventually causing perforation, which would need surgery repair. Another possibility with untreated or inadequate treated cases is the infected person becomes a long life carrier of the bacteria.
There are two basic actions that can protect you from typhoid fever, the most important prevention is to avoid risky foods and drinks and the second prevention is to get vaccinated against typhoid fever.
Foods and drinks which are considered risky are: fresh salads or raw vegetables, raw shellfish and cold cooked meats, fresh fruits, ice, or anything sold by street vendors. When these foods are unavoidable, you can try to re-wash it with bottled drinking water, boil it or peel fruits or vegetables with skin. The golden rule is: If you can’t peel it, boil it or cook it, don’t eat it.
Vaccination is not 100% protective. The commonly advised vaccination is the injection. The injection is given one time, and should be completed at least 1 week before travel. During the first year it gives 60 – 80% protection, the next two years its protection declines to 50 – 77%. Therefore, a booster dose is recommended every 2-3 years for people at high risk.