Typhoid Fever Disease

DESCRIPTION

Typhoid fever is an acute systemic illness unique to humans caused by Salmonella typhi. It is a classic example of enteric fever caused by the Salmonella family of bacteria.

It is endemic in some developing nations where sanitation is suboptimal. Majority of cases in North America are acquired after travel to endemic areas.
Mode of transmission is fecal-oral through ingestion of contaminated food (commonly poultry), water and milk. Incubation period varies from 7 to 21 days.
System(s) affected: Gastrointestinal, Pulmonary, Skin/Exocrine
Genetics: N/A
Incidence/Prevalence in USA: 300-500 cases per year
Predominant age: All ages
Predominant sex: Male = Female

SIGNS AND SYMPTOMS

Fever
Headache
Malaise
Abdominal discomfort/bloating/constipation
Diarrhea (less common)
Dry cough
Confusion/lethargy
Rose spot (transient erythematous maculopapular rash in anterior thorax or upper abdomen)
Splenomegaly
Hepatomegaly
Cervical adenopathy
Relative bradycardia
Conjunctivitis

CAUSES

Salmonella typhi

RISK FACTORS

Must be considered in any patient presenting with fever after tropical travel or exposed to chronic carrier

LABORATORY

Definitive diagnosis by isolation of S. typhi from blood. Isolation of S. typhi in sputum, urine or stool is presumptive diagnosis in typical clinical presentation.
Serology is nonspecific and usually not useful
If multiple blood cultures are negative or in patients with prior antibiotic therapy, diagnostic yield is better with bone marrow culture
Anemia, leukopenia (neutropenia), thrombocytopenia or evidence of DIC (disseminated intravascular coagulopathy) are supportive evidence. Elevated liver enzymes are commonly seen.

Drugs that may alter lab results:

Prior antibiotic therapy
Vaccination

Disorders that may alter lab results: N/A

PATHOLOGICAL FINDINGS

Classically, mononuclear proliferation involving lymphoid tissue of intestinal tract especially Peyer's patch in terminal ileum

SPECIAL TESTS

N/A

IMAGING

Consider serial plain abdominal films for evidence of intestinal perforation

DIAGNOSTIC PROCEDURES

Bone marrow aspirate for culture is rarely indicated

Typhoid fever vaccines

Name	Type	Dosing	Protection(1,2)	Note
Typhoid	Phenol killed	Several parenteral doses	50-70% up to 3 yrs	(3)
Ty21a	Oral, live attenuated	One capsule qOD for 4 doses	40-65% up to 7 yrs	(4)
Typhim vi	Capsular polysaccharide	Single IM dose	50-75% up to 3 yrs	(5)

Little data for travelers from developed countries
Any protection can be overwhelmed by a large inoculum
Generally not available, but can be given to infants
Do not give to children < 6 yrs of age
Do not give to children < 1 yr of age

APPROPRIATE HEALTH CARE

Inpatient if acutely ill
Outpatient for less ill patient or for carrier

GENERAL MEASURES

Fluid and electrolyte support
Strict isolation of patient's linen, stool and urine
Monitor clinically and consider serial plain abdominal films for evidence of perforation, usually in the third to fourth week of illness
Indication for treatment must be determined on an individual basis. Factors to be considered are age, public health (food handler, chronic care facilities, medical personnel), intolerance to antibiotics, and evidence of biliary tract disease.
For hemorrhage - need blood transfusion and shock management

SURGICAL MEASURES

Cholecystectomy may be warranted in carriers with cholelithiasis, relapse after therapy, or intolerance to antimicrobial therapy

ACTIVITY

Bedrest initially, then as tolerated

DIET

If abdominal symptoms severe, nothing by mouth. With improvement, normal low-residue diet, possibly enriched in calories.

PATIENT EDUCATION

Discussion of chronic carrier state and its complications
For family members, travelers or workers at risk, provide hygiene education, possibly vaccination

PREVENTION/AVOIDANCE

For travel to an endemic area, consider vaccination for typhoid, parenterally (phenol-killed or Vi vaccines) or live oral vaccine (Ty21a), particularly if traveler will have prolonged risk (>4 weeks)
Avoid tap water, salad/raw vegetables, unpeeled fruits, dairy products in tropical travel
Avoid poultry or poultry products left unrefrigerated for prolonged period of time
Consider vaccination for workers exposed to S. typhi, household or intimate exposure to a carrier of S. typhi

POSSIBLE COMPLICATIONS

Intestinal hemorrhage and perforation in distal ileum
Patient may become chronic carrier state (up to 3%) defined as persistent stool excretor for longer than 1 year
Predilection for seeding in the biliary tract exists and may become a focus for relapse of typhoid fever. Most common in female and the elderly (> 50 years old).
Osteomyelitis especially in sickle cell anemia, systemic lupus erythematosus, hematologic neoplasms and immunosuppressed hosts
Endovascular infection in the elderly and in patients with history of bypass operation or aneurysm
Rarely, endocarditis or meningitis

EXPECTED COURSE AND PROGNOSIS

Overall prognosis good with therapy. < 2% mortality rate; 15% relapse rate with some antibiotic treatments; 3% bowel perforation

ASSOCIATED CONDITIONS

N/A

AGE-RELATED FACTORS

Pediatric: Disease more critical in infants, but may be milder in children
Geriatric: Disease more serious in elderly
Others: N/A

PREGNANCY

Pregnancy is a common time for onset of, or increase in obesity

OTHER NOTES

N/A

ABBREVIATIONS

RDA = recommended daily allowance
BMI = body mass index

Clinical Investigations

ROLE OF HOMOEOPATHY

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