Typhoid fever vaccine and prevention

If you wish to avoid typhoid fever, proper sanitation and hygiene are of imperative importance. It is possible for humans to become asymptomatic carriers of typhoid fever. Such a person will not develop any symptoms, but he or she is still capable of spreading the disease to other humans.

You can only catch typhoid from a human source since animals do note become infected with Salmonella enterica serovar Typhi. You can therefore normally only become infected typhoid fever in environments where human faeces or urine is allowed to contaminate products that you eat or drink. Even though animals can’t get typhoid fever, flying insects that feeds on faeces may occasionally transfer Salmonella enterica serovar Typhi to food and water.

The World Health Organization currently recommends two different vaccines against typhoid fever. Both are 50-80% effective and are considered superior to the old killed whole-cell vaccine since the old injectable vaccine comes with a higher rate of side effects, such as pain and inflammation in the injection area. The old vaccine is still used in countries where the new vaccines are not yet available.

Of the two anti-typhoid fever vaccines recommended by WHO, one is injected and one is taken orally. The injectable vaccine is a Vi capsular polysaccharide vaccine (sold as Typhim Vi) while the oral vaccine is a live, oral Ty21s vaccine (sold as Vivotif Berna).

Typhoid fever

Typhoid fever is a disease caused by the bacterium Salmonella enterica serovar Typhi. The disease is known under several different names in English, including enteric fever, bilious fever, nervous fever, or Yellow Jack.

When left untreated, typhoid fever will normally progress in four stages in the human body with each stage lasting roughly one week. During the first week, the temperature will rise slowly and the patient can develop symptoms such as a low resting heart rate, headaches, couch, and general discomfort. Nose bleeding and abdominal pain is also fairly common.

During the second week, the fever will become really high and typically stay around 104°F (40°C). The resting heart rate is low and the patient is often delirious. The right lower quadrant of the abdomen will usually ache and become distended. In roughly 1/3 of the patients, rose spots are visible on the lower chest and abdomen. Spleen and liver are enlarged and tender. Diarrhea can occur during the second stage and the stool will then usually be green. Some patients develop constipation instead.

During the third stage, several different complications can set in, such as acute inflammation of the brain, inflammation of the gall bladder, inflammation of bone, inflammation of the inner layer of the heart, intestinal haemorrhage, perforation of the final section of the small intestine, and metastatic abscesses. The fever is normally very high during the third stage and is fairly constant over 24 hours. Dehydration can easily make the patient delirious. Fatalities are common during the third stage of typhoid fever.

By the end of the third week, the fever begins to decrease and will then decrease further during the fourth week.