Diseases Caused by Bacteria > Typhoid

Typhoid is a highly infectious bacterial disease of the intestine caused by Salmonella typhi. It is an enteric fever affecting the intestines.

Causative Organism:

• The causative organism is Salmonella typhi.
• It is a Gram-negative bacterium.
• Its pathogenicity is due to O antigen, and its flagella contain H antigen.

Entry and Spread in Body:

• The bacteria enter the body through contaminated food and water.
• They reach the small intestine and may migrate to other organs through blood.

Symptoms:

• Sustained or prolonged high fever, usually 39–40°C or up to 104°F.
• Headache and weakness.
• Abdominal pain or stomach pain.
• Constipation; diarrhoea may also occur.
• Loss of appetite, nausea, fatigue, and severe body pain.
• A rose-coloured rash, a white-coated tongue, and a cough may be present.

Severe Effects:

• Intestinal perforation may occur in severe cases.
• Haemorrhage, breathlessness, irregular heartbeat, and death may occur if untreated.
• Relapse may occur about two weeks after apparent recovery.

Diagnosis:

• Typhoid is confirmed by the Widal test.
• Blood, urine, and faeces may also be tested for confirmation.

Treatment:

• Antibiotics are used in treatment.
• The patient may be isolated.
• Proper nursing care and frequent fluids are advised.
• In severe cases, surgical removal of the gall bladder may be required.

Spread of Infection:

• The disease spreads through contaminated food and water.
• Houseflies and cockroaches may transfer the bacteria from faecal matter to food.
• Poor hygiene and poor sanitation help in its spread.

Carrier State:

• Some recovered persons become carriers.
• Such persons harbour the bacteria in the intestine and excrete them in faeces.
• They may remain infectious without showing symptoms.
• Mary Mallon, known as Typhoid Mary, is a classic example.

Prevention

• Proper sanitation is necessary.
• Open food should be avoided.
• Hygienic food and safe water should be used.
• Immunisation helps in prevention.

Vaccination

• Oral Ty21a vaccine is mentioned.
• Injectable typhoid polysaccharide vaccine is also mentioned.
• TAB vaccine provides immunity for about 3 years.