Typhoid
A bacterial disease spread through contaminated food or water.
Typhoid fever, also known as typhoid, is an orally contracted disease caused by the bacterium Salmonella enterica serotype Typhi (Salmonella Typhi). It is a type of enteric fever, along with paratyphoid fever, and is spread by ingesting food or water contaminated with the feces of an infected person. Only humans can be infected; there are no known animal reservoirs. Symptoms vary from mild to severe, usually beginning six to 30 days after exposure, and include gradual high fever, weakness, abdominal pain, constipation, headaches, and mild vomiting. Without treatment, symptoms may last weeks or months, and the risk of death may be as high as 20%.
- Caused by
- Salmonella enterica serotype Typhi
- Transmission
- Fecal-oral route via contaminated food or water
- Symptoms onset
- 6 to 30 days after exposure
- Without treatment risk of death
- Up to 20%
- With treatment risk of death
- Between 1% and 4%
- Global cases in 2015
- 12.5 million new cases
Lore & Background
Typhoid fever is caused by the Gram-negative bacterium Salmonella enterica subsp. enterica serovar Typhi, which infects and replicates only within humans. The bacteria grow in the intestines, Peyer's patches, mesenteric lymph nodes, spleen, liver, gallbladder, bone marrow, and blood. Risk factors include limited access to clean drinking water and poor sanitation. Asymptomatic carriers can excrete the bacteria in stool for a year or more after the acute stage, remaining contagious. The disease is distinct from typhus, which is caused by unrelated bacteria; the name 'typhoid' means 'resembling typhus' due to similar symptoms, and the two were not recognized as distinct until the 1800s.
Reader's Guide
Children are most commonly affected. Diagnosis is performed by culturing S. typhi from patient samples or detecting an immune response from blood samples, though diagnostic tools in regions where typhoid is most prevalent are limited in accuracy and specificity. Antibiotic resistance has been developing, making treatment more difficult. A typhoid vaccine can prevent about 40–90% of cases during the first two years, with some effect up to seven years. Efforts to prevent the disease include providing clean drinking water, good sanitation, and handwashing.
Did You Know?
- Typhoid fever is caused by Salmonella enterica serotype Typhi, which is different from the Salmonella bacteria that usually cause salmonellosis.
- Without treatment, the risk of death from typhoid fever may be as high as 20%; with treatment, it is between 1% and 4%.
- The Widal test, used for diagnosis, is time-consuming and prone to significant false positives.
- A typhoid vaccine can prevent about 40–90% of cases during the first two years.
Frequently Asked Questions
Who is Typhoid?
Typhoid is an orally acquired bacterial infection caused by Salmonella enterica serotype Typhi. It belongs to the enteric fever family alongside paratyphoid fever and exclusively infects humans, with no known animal reservoir.
What are Typhoid's powers/role?
Typhoid spreads through the fecal-oral route, entering the body when a person consumes food or water tainted by the feces of an infected individual. Once established, it triggers a gradual high fever, abdominal pain, weakness, constipation, headaches, and mild vomiting.
How does Typhoid's story end?
Without medical intervention, Typhoid can persist for weeks or months and carries a mortality rate as high as 20%. With proper antibiotic treatment, the fatality rate drops to roughly 1–4%, allowing most patients to recover fully.
Why is Typhoid important?
Typhoid remains a major global public-health burden, with an estimated 12.5 million new cases reported worldwide in 2015 alone. Its exclusive dependence on humans as a host makes eradication especially difficult in communities with limited sanitation infrastructure.
What is Typhoid's timeline?
After initial exposure, Typhoid typically takes six to thirty days before its first symptoms appear. The progression is gradual rather than sudden, with fever and malaise building over days before reaching peak severity.
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