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    Haemophilus influenzae type b

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To obtain or inquire about an immunization record for yourself or your child, please contact your local public health unit.

Haemophilus influenzae is a gram-negative bacteria that only affects humans. There are six strains of Haemophilus influenzae (serotypes "a" through "f") as well as non-typeable strains. Diseases caused by the organism range from serious invasive illnesses such as meningitis and epiglottitis to non-invasive disease such as middle ear infections. Haemophilus influenzae serotype b (Hib) is the most pathogenic and often results in serious illness.

Hib is spread through contact with respiratory droplets and nasal or throat discharges of infected persons. The incubation period is unknown but is thought to be about 2 to 4 days. Hib can spread as long as Hib bacteria are present in the patient, which may be for a prolonged period. Hib is no longer communicable 24 to 48 hours after starting effective antibiotic treatment.

Before the introduction of this vaccine, Hib was the most common cause of bacterial meningitis and a leading cause of other serious infections in young children. Over half of affected children developed meningitis, while others experienced infections such as epiglottitis, bacteremia, cellulitis, pneumonia, septic arthritis, and middle ear infections. Complications include deafness and neurological disorders. The Hib vaccine is routinely administered in combination with vaccines at two, four and six months of age, with a booster dose given at 18 months of age. Following the introduction of the infant Hib vaccination program, there has been a decline in disease incidence in all age groups, including those not targeted by vaccination, and Hib disease is now rare in Ontario.  

Page last reviewed:  
Page last updated: 2017-03-28 10:23 AM
Uncontrolled print copy. Valid only on day of Print: [date]
Page updated on [date/time] 2017-03-28 10:23 AM
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