From the Guidelines
Haemophilus influenzae type b (Hib) prophylaxis is recommended for unvaccinated or incompletely vaccinated close contacts of a person with invasive Hib disease, particularly in households with children under 4 years old, using rifampin as the preferred prophylactic agent. The dosage of rifampin is 20 mg/kg once daily (maximum 600 mg) for 4 days in children, or 600 mg once daily for 4 days in adults [ 1 ]. For infants younger than 3 months, the dose is 10 mg/kg once daily for 4 days [ 2 ].
Key Considerations
- All household contacts should receive prophylaxis simultaneously to prevent recolonization [ 1 ].
- Prophylaxis should be initiated within 7 days of the index case's hospitalization for optimal effectiveness.
- Pregnant women should consult their healthcare provider before taking rifampin due to potential risks.
- Rifampin works by eliminating nasopharyngeal carriage of Hib, thereby reducing transmission risk [ 3 ].
- Patients should be informed that rifampin may cause orange discoloration of urine, tears, and contact lenses, and may reduce the effectiveness of oral contraceptives, necessitating alternative contraception during treatment.
Additional Recommendations
- Vaccination should be given to all previously unvaccinated household contacts, under the age of 10 [ 1 ].
- Household contacts are defined as any individual who has had prolonged close contact with the index case in a household-type setting during the seven days before the onset of illness [ 2 ].
From the Research
Haemophilus influenzae type b (Hib) Prophylaxis
- Haemophilus influenzae serotype b (Hib) can cause severe life-threatening disease in healthy individuals, with over 80% of cases in the pre-vaccine era occurring in children under five years of age 4
- The introduction of Hib conjugate vaccine into routine childhood immunisation programmes has resulted in a dramatic reduction in the incidence of invasive Hib disease across all age groups 4, 5, 6, 7, 8
Chemoprophylaxis
- Rifampicin at a dose of 20mg/kg/day for 4 days is highly effective in eradicating pharyngeal carriage of Hib and reducing the risk of invasive Hib disease among household and pre-school contacts 4
- Children under 10 years of age who develop invasive Hib disease should also receive rifampicin chemoprophylaxis to eliminate carriage and have Hib antibody levels tested around four weeks after infection 4
- If there is a vulnerable individual (child younger than 10 years or an immunosuppressed or asplenic individual of any age) among the household contacts of a case, all members of that household, including the index case, should receive chemoprophylaxis 4
Vaccination
- Hib conjugate vaccines are highly immunogenic and efficacious in children older than 12-15 months of age, and some are also effective in infants as young as 2 months old 5
- The use of Hib conjugate vaccine on a population scale has been greatly effective in reducing the incidence of invasive Hib disease 5, 6, 7, 8
- More than 90% of countries worldwide have implemented Hib-conjugate vaccination in their national immunization programs 7
Disease Control and Elimination
- Further improving global Hib vaccination coverage may result in disease elimination 7
- Continuous surveillance is needed to anticipate potential re-emergences and devise the best strategies for prevention and control of disease 7
- Hib vaccination should be considered in the few countries who have not yet implemented it, to decrease associated morbidity and mortality 7