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The incidence of typhoid fever in the United States has markedly decreased since the early 1900s. Today, less than 500 cases are reported annually in the United States, mostly in people who recently have traveled to endemic areas. This is in comparison to the 1920s, when over 35,000 cases were reported in the U.S. This improvement is the result of improved environmental sanitation. Mexico and South America are the most common areas for U.S. citizens to contract typhoid fever. India, Pakistan, and Egypt are also known high-risk areas for developing this disease. Worldwide, typhoid fever affects more than 13 million people annually, with over 500,000 patients dying of the disease.
Mode of Transmission
- Humans are the only source. No animal or environmental reservoirs have been identified.
- Typhoid and paratyphoid fever are most often acquired through consumption of water or food that have been contaminated by feces of an acutely infected or convalescent individual or a chronic asymptomatic carrier.
- Transmission through sexual contact, especially among men who have sex with men, has rarely been documented.
What are the symptoms of the disease?
The incubation period is 10 to 20 days and depends on, among other things, how large a dose of bacteria has been taken in.
In the mild disease, the bacterium is eliminated very early in the course of the disease and there are perhaps only mild symptoms. It's possible to become a healthy carrier of infection.
There are two phases of classic typhoid fever:
- 1st phase: the patient's temperature rises gradually to 40ºC, and the general condition becomes very poor with bouts of sweating, no appetite, coughing and headache. Constipation and skin symptoms may be the clearest symptoms. Children often vomit and have diarrhoea. The first phase lasts a week and towards the end the patient shows increasing listlessness and clouding of consciousness.
- 2nd phase: in the second to third weeks of the disease, symptoms of intestinal infection are manifested and the fever remains very high and the pulse becomes weak and rapid. In the third week, the constipation is replaced by severe pea-soup-like diarrhoea. The faeces may also contain blood. It's not until the fourth or fifth week that the fever drops and the general condition slowly improves.
How is the disease diagnosed?
The clinical picture together with information on travel may be a good pointer for the doctor in moderate to severe cases. For the final diagnosis to be established, the bacteria have to be detected in samples from the stool, blood or other tissue. A serology test (Widal) not much used in the UK can be very useful overseas in areas where the infection is more common.
Malaria also needs to be considered as another possible explanation for the symptoms of the disease when the patient has been travelling in a malarial area.Getting vaccinated
If you are traveling to a country where typhoid is common, you should consider being vaccinated against typhoid. Visit a doctor or travel clinic to discuss your vaccination options.
Remember that you will need to complete your vaccination at least 1 week before you travel so that the vaccine has time to take effect. Typhoid vaccines lose effectiveness after several years; if you were vaccinated in the past, check with your doctor to see if it is time for a booster vaccination. Taking antibiotics will not prevent typhoid fever; they only help treat it.
How is typhoid fever treated?
Treatment may require admission to hospital, and loss of fluid and salt is treated with fluid therapy as appropriate.
The bacterium is controlled with antibiotics, and in rare cases steroid medicines are also included in the treatment.
Prevention
Within the hospital setting, infected people are cared for in isolation. Proper hand hygiene is the most important way of preventing further spread in hospital.
Stool samples are also taken from members of the patient's family to identify any 'healthy' carriers.
Posted in: Typhoid Fever
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