Prevention of Hemophilus influenzae type b disease
J. D. Band, D. W. Fraser and G. Ajello
To determine the efficacy of rifampin prophylaxis in eradication of
oropharyngeal carriage of Hemophilus influenzae type b and prevention of
secondary H influenzae type b disease, we conducted a multicenter
placebo-controlled trial among selected persons with invasive H influenzae
type b disease. Households and day-care classrooms were randomized so that
their members received either rifampin (initially at a dose of 10
mg/kg/dose for two to four days [rifampin-10], but subsequently at 20
mg/kg/dose for four days [rifampin-20]) or placebo. Pretherapy H influenzae
type b colonization rates were similar in the treatment groups. Therapy
with either rifampin regimen significantly reduced carriage (rifampin-20,
97%; rifampin-10, 63%; placebo, 28%). New acquisition of carriage was also
significantly reduced by either rifampin regimen (rifampin-20 or
rifampin-10, 2% v placebo, 6%). No rifampin-resistant H influenzae type b
isolates emerged after treatment. Four of 765 placebo-treated contacts
experienced secondary disease in contrast to zero of 1,112 rifampin-treated
contacts. Because chemoprophylaxis of close contacts with rifampin seems to
reduce significantly the risk of secondary H influenzae type b disease, we
recommend the administration of prophylaxis in households or day-care
classrooms where children younger than 4 years have been exposed to the
disease.
