What intravenous (IV) antibiotics are recommended for a 1-year-old patient suspected of having typhoid fever?

IV Antibiotics for 1-Year-Old with Suspected Typhoid Fever

For a 1-year-old with suspected typhoid fever, intravenous ceftriaxone at 50-75 mg/kg/day (divided every 12-24 hours) is the recommended first-line empiric therapy, particularly given widespread fluoroquinolone resistance in endemic regions. 1

Primary Recommendation: Ceftriaxone

• Ceftriaxone is the preferred IV agent for empiric treatment of suspected typhoid in young children, with dosing of 50-75 mg/kg/day given once daily or divided every 12 hours 1
• This recommendation is particularly strong for patients from Asia or other regions with high fluoroquinolone resistance, where more than 70% of Salmonella typhi isolates are fluoroquinolone-resistant 1
• All isolates reported to UK surveillance in 2006 remained sensitive to ceftriaxone, supporting its reliability 1

Alternative IV Options Based on Resistance Patterns

If Fluoroquinolone Sensitivity is Confirmed:

• IV ciprofloxacin (10 mg/kg/day) can be used if the isolate is confirmed sensitive to nalidixic acid (not just ciprofloxacin disc testing alone) 1
• Ciprofloxacin achieves rapid fever clearance (mean 3.3 days) with 94% clinical cure rates in severe typhoid 2
• Critical caveat: Ciprofloxacin disc testing alone is unreliable for S. typhi; nalidixic acid sensitivity must also be confirmed 1

For Extensively Drug-Resistant Strains:

• If ceftriaxone resistance is suspected or confirmed (emerging in Pakistan), azithromycin becomes the preferred alternative, though IV formulation availability may be limited 1, 3
• Azithromycin shows lower relapse rates (OR 0.09,95% CI 0.01-0.70) compared to ceftriaxone 1

Treatment Duration and Monitoring

• Continue treatment for 14 days to minimize relapse risk (relapse rates: ceftriaxone <8%, fluoroquinolones <8%, azithromycin <3%) 1
• Expect fever clearance within 3-5 days with appropriate therapy 1, 2
• If no clinical improvement by 72 hours, consider resistance and switch to alternative agent 1

Age-Specific Dosing Considerations for 1-Year-Old

• At 1 year of age, the child falls into the 8-21 day to 12-month category where ampicillin plus gentamicin or ceftazidime is recommended for undifferentiated fever 1, 4
• However, once typhoid is specifically suspected (based on travel history, endemic exposure, or clinical presentation), ceftriaxone becomes the targeted choice 1
• For this age group: Ceftriaxone 50 mg/kg once daily IV is appropriate 1

Critical Pitfalls to Avoid

• Do not rely on ciprofloxacin disc testing alone for susceptibility determination; nalidixic acid resistance predicts fluoroquinolone treatment failure 1
• Do not use ceftriaxone in neonates with hyperbilirubinemia due to kernicterus risk, but this is not a concern at 1 year of age 4
• Do not use oral cefixime as initial therapy for severe or hospitalized cases, as it shows higher failure rates (RR 13.39) compared to fluoroquinolones and is less reliable than IV ceftriaxone 1, 3
• Avoid empiric fluoroquinolones without susceptibility data in patients from South Asia, where resistance exceeds 70% 1, 3

When to Start Empiric Therapy

• Begin IV antibiotics immediately if the child appears clinically unstable or has signs of severe disease (altered consciousness, shock, complications) while awaiting blood culture results 1
• Blood cultures have highest yield within the first week of symptoms (40-80% sensitivity) 1
• Obtain blood cultures before starting antibiotics, but do not delay treatment in severely ill children 1

Switching to Oral Therapy

• Once clinically improved and afebrile for 24-48 hours, consider switching to oral azithromycin to complete the 14-day course 1
• Oral cefixime is an option but has higher failure rates (4-37.6%) compared to other agents 1