Typhoid is caused primarily by Salmonella typhi. The disease is acquired by ingestion of food or water that has been contaminated by a human, who has the acute disease or is recently convalescent or is an asymptomatic chronic faecal shedder of typhoid bacilli.
Reservoir
Human, especially gallbladder carriers and, rarely, urinary carriers.
Incubation period
Usually one to three weeks (depending on the infective dose, from three days to three months).
Signs and Symptoms
- High fever (103˚F)
- 'Rose spots'
- Loss of appetite
- Stomach pains
- Diarrhoea
- Headache
- Involvement of lymphoid tissue
- Splenomegaly
- Weakness
Diagnosis
Typhoid bacilli, readily isolated in blood, urine and faeces.
Treatment
- Antibiotics prescribed by medical doctor (tetracycline or chloramphenicol).
- A patient who is not posing a special risk need not be excluded from work or school provided they have normal stools and no other symptoms. Food handlers suffering from typhoid should be excluded from work for at least 6 months.
Control and Prevention
- Control requires one to know of carriers, control of the occupation activities, safe water supply and effective sewage systems.
- Educate public on importance of hand washing and food handling.
- Dispose of human faeces in a sanitary manner.
- Protect, purify, and chlorinate public water supplies.
- Control flies by screening, spraying with insecticides.
- Use cleanliness if food preparation and handling.
- Pasteurise or boil all milk and dairy products.
- Exclude carriers from handling food and from providing patient care.