What are the diagnostic and treatment approaches for enteric fever?

Diagnostic and Treatment Approaches for Enteric Fever

Blood culture is the recommended initial diagnostic test for enteric fever, with bone marrow culture being particularly valuable if antimicrobial agents have been administered. 1

Diagnostic Approach

Clinical Suspicion

• Enteric fever should be suspected in patients with persistent fever, especially with relative bradycardia and normal to low WBC count, particularly in travelers returning from endemic areas 2
• Complete blood count typically shows leukopenia with relative lymphocytosis and monocyte predominance, which may suggest the presence of an intracellular pathogen such as Salmonella 2
• Clinical features alone have poor diagnostic accuracy, with absence of cough having the highest sensitivity (65.5%) among clinical features 3

Recommended Diagnostic Tests

• Culture-independent, panel-based multiplex molecular diagnostics from stool and blood specimens should be performed when enteric fever is suspected 1
• Blood culture is the standard initial diagnostic test with approximately 50% sensitivity 1
• Additional cultures that may be beneficial include:
  • Bone marrow culture (higher sensitivity, particularly valuable if antimicrobials have been administered) 1
  • Stool culture 1
  • Duodenal fluid culture 1
  • Urine culture 1
• Serologic tests should NOT be used to diagnose enteric fever due to poor performance characteristics 1

Diagnostic Challenges

• Enteric fever diagnosis based on clinical presentation is challenging due to overlapping symptoms with other febrile illnesses 4
• Current laboratory tests display suboptimal sensitivity and specificity 4
• Blood culture, while recommended, has limited sensitivity and is technically demanding 5

Treatment Approach

Antimicrobial Therapy

• Patients with signs of invasive disease or sepsis should be treated with antibiotics 6
• Ciprofloxacin is indicated for typhoid fever (enteric fever) caused by Salmonella typhi 7
• The efficacy of ciprofloxacin in eradicating the chronic typhoid carrier state has not been demonstrated 7
• Appropriate culture and susceptibility tests should be performed before treatment to determine antimicrobial susceptibility 7
• Therapy may be initiated before results are known and adjusted once susceptibility results become available 7

Fluid and Electrolyte Management

• Oral rehydration solution (ORS) should be administered until clinical dehydration is corrected, followed by maintenance fluids to replace ongoing losses 6
• Intravenous fluids may be necessary for patients with severe dehydration or those unable to tolerate oral intake 6
• All patients should be evaluated for dehydration, which increases the risk of life-threatening illness and death 6

Symptomatic Management

• Antimotility drugs (e.g., loperamide) should NOT be given to children <18 years of age with acute diarrhea 6
• Loperamide should be avoided in cases of inflammatory diarrhea or diarrhea with fever, which is common with Salmonella infection 6
• Antinausea medications may be given to facilitate oral rehydration tolerance in children >4 years of age and adolescents with vomiting 6

Prevention of Transmission

• Hand hygiene should be performed after using the toilet, changing diapers, before and after preparing food, and before eating 6
• Appropriate food safety practices should be followed to avoid cross-contamination 6
• Ill people with diarrhea should avoid swimming, water-related activities, and sexual contact with others while symptomatic 6

Common Pitfalls to Avoid

• Relying solely on clinical features for diagnosis, as they have poor sensitivity and specificity 3
• Using serologic tests for diagnosis of enteric fever 1
• Using antimotility agents in children or in adults with inflammatory diarrhea 6
• Failing to adequately rehydrate patients, which is the cornerstone of management 6
• Not considering antibiotic resistance patterns when selecting empiric therapy 7