What is the treatment for Haemophilus influenzae type b (HiB) infection?

Treatment of Haemophilus influenzae Type b (HiB) Infection

For invasive HiB infections including meningitis, treat with ceftriaxone 2g IV every 12 hours or cefotaxime 2g IV every 6 hours for 10 days. 1

Acute Treatment of Invasive Disease

First-Line Antibiotic Therapy

• Third-generation cephalosporins are the preferred agents due to their excellent CSF penetration and activity against both β-lactamase-producing and non-producing strains 1, 2
• Ceftriaxone 2g IV every 12 hours for 10 days 1
• Cefotaxime 2g IV every 6 hours for 10 days 1
• These agents eradicate Hib colonization, eliminating the need for additional rifampin prophylaxis in the index patient 3

Alternative Therapy Options

• Moxifloxacin 400 mg once daily can be used if cephalosporins cannot be administered 1
• Chloramphenicol 25 mg/kg every 6 hours may be considered in settings where cephalosporins are unavailable 1

Critical Pitfall to Avoid

• Never use vancomycin alone for HiB meningitis due to inadequate CSF penetration 1

Chemoprophylaxis Strategy

For the Index Patient

• Index patients aged <2 years treated with antibiotics OTHER than cefotaxime or ceftriaxone must receive rifampin before hospital discharge 3
• Rifampin dosage: 20 mg/kg once daily (maximum 600 mg) for 4 days 1, 4
• No rifampin needed if treated with cefotaxime or ceftriaxone, as these eradicate colonization 3, 5

For Household Contacts

• Rifampin chemoprophylaxis is indicated for the index patient (unless treated with cefotaxime/ceftriaxone) AND all household contacts when:
  • Any household member is aged <4 years and not fully vaccinated 3, 1
  • Any household member is aged <18 years and immunocompromised, regardless of vaccination status 3, 5
• Rifampin achieves >95% eradication of nasopharyngeal carriage 3
• Secondary attack rates are highest among household contacts aged <12 months (6%) and <24 months (3%) 3

For Child Care Contacts

• Rifampin chemoprophylaxis is recommended when two or more cases of invasive HiB disease occur within 60 days AND unimmunized or underimmunized children attend the facility 3, 5
• When indicated, prescribe for all attendees regardless of age or vaccine status, and for all child care providers 3

Critical Pitfall to Avoid

• Failure to provide appropriate chemoprophylaxis to close contacts can result in secondary cases, particularly in vulnerable young children 1, 4

Treatment Monitoring and Failure

• Evaluate for antibiotic resistance if no clinical improvement occurs after 48-72 hours 1
• Consider adding or switching to an alternative agent if treatment failure occurs 1
• Local antibiotic resistance patterns should guide therapy selection 1

Special Populations

Immunocompromised Patients

• Patients with functional or anatomic asplenia, HIV infection, immunoglobulin deficiency, complement deficiency, or those receiving chemotherapy/radiation are at increased risk 3
• Children who develop HiB disease despite appropriate vaccination should be evaluated for immunological deficiency 3

Return to School/Childcare

• Children with invasive HiB disease can return to childcare or school after completing at least 24 hours of effective antibiotic treatment 5
• Children must be clinically well enough to participate in activities 5

Important Distinction

• These treatment and chemoprophylaxis recommendations apply ONLY to HiB (type b) disease 3
• Chemoprophylaxis is NOT recommended for contacts of persons with invasive disease caused by nontype b H. influenzae, as secondary transmission has not been documented 3