Haemophilus influenzae Type B Infections

Haemophilus influenzae type B (HIB) is a potentially serious bacterial infection that occurs mostly in young children aged two months to two years. These bacteria, not to be confused with the influenza virus, can cause meningitis and other serious infections in young children including epiglottitis which is an infection of the area around the vocal cords, considered a medical emergency with potentially devastating consequences. HIB also causes middle ear infections, pneumonia and bone/joint infections. HIB meningitis has a fatality rate of about 5 percent and can result in severe neurologic/brain consequences (seizures, paralysis) in 10 to 15 percent of patients as well as deafness in 15 to 20 percent.

HIB is spread through the nasal passage by contact with respiratory droplets or nasal or throat discharges of infected individuals and has an incubation period of about two to four days. After forty-eight hours of antibiotics, a person infected with HIB is no longer contagious.

Before the introduction of HIB vaccines in the late 1980s, HIB was the most common cause of bacterial meningitis and a leading cause of other serious infections in young children, despite the use of antibiotics. Clearly, when a vaccine to prevent this devastating disease was introduced in the late 1980's, it made a big difference. In fact, since the introduction of HIB vaccines in North America and other countries, the overall incidence of HIB disease has decreased dramatically.

On a personal note, I remember during my pediatric training in the early 1980s that we dreaded this infection as we literally saw dozens of children with serious HIB infections and its complications weekly. At that time despite our best efforts to provide urgent supportive care and antibiotics, we did see children die of this infection or suffer severe life-long and at times, debilitating complications and consequences.