Typhoid fever (a.k.a. - enteric fever) - causes severe abdominal pain, fever, diarrhea, rash (in some)
Appearance (under a microscope)
Gram-negative, non–spore-forming, facultatively anaerobic bacilli (like pink hot dogs)
Habitat & Transmission
- Humans are the only known source
- Transmitted by close contact with an infected individual
- Also can be transmitted by stool-contaminated food or water
- Has developed resistance to commonly-used antibiotics (such as chloramphenicol, ampicillin, and trimethoprim)
- Fimbriae - string-like projections that help with attachment to intestinal wall before invasion of cells
- Inject proteins into intestinal cells, instructing them to allow entry of the bacteria
- Once inside intestinal cells, they trigger an inflammatory response
- Able to survive and replicate inside macrophages
- Can cause a symptom-free carrier state in some people - carriers who work as food preparers can spread the illness to many people
- Eventually, the immune system can control infection. T-cells and B-cell antibodies play a major role in defeating Salmonella typhi.
- A vaccine is available and is often used for people traveling to areas where typhoid fever is common
- Sensitive to antibiotics such as the fluoroquinolones, third-generation cephalosporins (i.e., rocephin), and azithromycin
- Typhoid fever causes an estimated 16 million cases worldwide and 600,000 deaths each year (mostly in developing countries)
- Before antibiotics were discovered, approximately 15% of patients with typhoid fever died. Now with antibiotic treatment, approximately 0.4% of persons with typhoid fever in the United States will die from the illness.
- Time from exposure to illness - 7 to 14 days
- Duration of illness - 4 weeks (without antibiotics)
Photo 1 - Salmonella typhi bacteria (cause typhoid fever). United States Center for Disease Control (CDC)12/18/2006. Used with permisssion.
Photo 2 - Mary Mallon (1870-1938) was nicknamed "Typhoid Mary". This is an illustration that appeared in 1909 in The New York American.
Last Updated (Tuesday, 23 June 2009 04:53)