The best summary for enteric fever

1. Enteric fever
Typhoid fever
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2. Acute generalized infection of the
reticuloendothelial system, intestinal lymphoid
tissue
Typhoid fever, also known simply as typhoid, is
a common worldwide bacterial disease,
transmitted by the ingestion of contaminated
food or water by Salmonella
It is characterized by severe systemic illness with
fever and abdominal pain
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3. Pathogen
Infection with one of several Salmonella species
◦ Salmonella enterica serotype typhi (S. typhi)
◦ Salmonella paratyphi A
◦ Salmonella schottmuelleri (Salmonella paratyphi B)
◦ Salmonella hirschfeldii (Salmonella paratyphi C)
◦ Salmonella choleraesuis
CLINICALLY INDISTINGUISHABLE!

4. Transmission
Mainly in underdeveloped areas with poor sanitation
Humans are the only known hosts of Salmonella Typhi
fecal-oral Transmission
• close contact with patients or carriers
• contaminated water and food
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5. Lifecycle
1. Oral uptake of pathogen
2. Distal ileum: migration into the Peyer patches and
disseminate via lymphatic or hematogenous route
3. Infection of macrophages (reticuloendothelial system)→
nonspecific symptoms
4. Spread from macrophages to the bloodstream: septicemia
→ systemic disease
5. Migrates back to intestine → excretion in feces
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6. Clinical features
General
◦ Incubation period: 5–30 days (most commonly 7–14 days)
◦ If left untreated, three different disease stages, each lasting a
week, classically occur.
◦ After 3 weeks of disease: slow regression of symptoms; patients
may become chronic Salmonella carriers
◦ Typhoid fever is a systemic disease; it is not limited to the
gastrointestinal system!
◦ Typhoid fever must always be considered in the case of
persistent fever of unknown origin in endemic region!
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7. Progression of illness
Week 1
◦Body temperature rises gradually
◦Relative bradycardia
◦Constipation or diarrhea
◦Headache
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8. Week 2
◦ Persistent fever, but no chills; mostly unresponsive
to antipyretics
◦ Nonspecific abdominal pain and headaches
◦ Rose-colored spots appears on the lower chest and abdomen
(most commonly around the navel).
◦ Typhoid tongue: greyish/yellowish-coated tongue with red edges
◦ Yellow-green diarrhea, comparable to pea soup
◦ Neurological symptoms (delirium, coma)
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9. Week 3
◦Clinical features of week 2
◦Additional possible complications include:
◦Intestinal bleeding and perforation
◦Hepatosplenomegaly
◦Rarely causes sepsis, meningitis, myocarditis, and
renal failure
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10. Diagnostics
◦ Laboratory tests
◦ Anemia ,Leukopenia or leukocytosis, Abnormal liver function tests
◦ Pathogen detection
◦ Blood cultures: the most common used 80~90% positive during
the first 2 weeks of illness 50% in 3rd week not easy in 4th week
◦ Stool cultures often negative despite active infection, better in
3~4 weeks
◦ The bone marrow culture the most sensitive (98%) test specially
in patients pretreated with antibiotics
◦ Serology often nonspecifically elevated by
immunization or previous infections
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11. Treatment
First stabilize and resuscitate the patient if it is required
Medication
Ciprofloxacin oral adults: 500 mg bid for 14 days
Ciprofloxacin IV 400 mg bid who cannot take oral medication
Ceftriaxone IV adults: 1-2 g daily for 7 days
Chloramphenicol 500-750mg qid orally or IV for 14 days
Azithromycin 1g stat, then 500mg-1g orally oD for 5-7 days

12. Complication
Chronic Salmonella carrier
◦ Definition: positive stool cultures 12 months after overcoming the disease
◦ Presentation: typically asymptomatic
◦ Treatment: ciprofloxacin administered for at least 1 month
◦ Chronic carriers are not allowed to work in the food industry.
◦ Increased risk for cholangiocarcinoma(bile duct cancer)
Intestinal hemorhage/perforation,Hepatitis,Myocarditis, Encephalopathy, Meningitis
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13. Prevention
Food and water
◦ Vaccination is not entirely effective. Measure must
therefore be implemented to avoid exposure.
Vaccination
◦ Indication: The WHO recommends typhoid fever vaccination
to those traveling to high-risk areas (East and Southeast
Asia, Latin America, Africa).
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14. Reference
Ryan ET, Andrews J. Epidemiology, Microbiology, Clinical
Manifestations, and Diagnosis of Enteric (Typhoid and Paratyphoid)
Fever. In: Post TW, ed. UpToDate. Waltham, MA: UpToDate.
https://www.uptodate.com/contents/epidemiology-microbiology-
clinical-manifestations-and-diagnosis-of-enteric-typhoid-and-
paratyphoid-fever. Last updated November 27, 2017.
Brusch JL. Typhoid Fever. In: Bronze MS. Typhoid Fever. New York, NY:
WebMD. https://emedicine.medscape.com/article/231135. Updated
May 18, 2017. Accessed December 18, 2017.Centers for Disease Control
and Prevention. Typhoid & Paratyphoid Fever.
https://wwwnc.cdc.gov/travel/yellowbook/2018/infectious-diseases-
related-to-travel/typhoid-paratyphoid-fever. Updated May 31, 2017.
Ryan ET, Andrews J. Treatment and Prevention of Enteric (Typhoid and
Paratyphoid) Fever. In: Post TW, ed. UpToDate. Waltham, MA:
UpToDate. https://www.uptodate.com/contents/treatment-and-
prevention-of-enteric-typhoid-and-paratyphoid-fever. Last updated
November 27, 2017.
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