Questions & Answers
Haemophilus B - The Disease
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  1. What is Haemophilus Type B disease?

    Haemophilus type b disease is caused by bacteria called Haemophilus influenzae type b, or Hib for short. Sometimes it’s called “H. flu.”

    There are six different types of this bacteria: a through f. Type b organisms account for 95% of all strains that cause serious Hib disease, and this is the type against which the Hib vaccine protects.

  2. How common is Hib disease in the United States?
    Before the introduction of a Hib vaccine, H. influenzae type b (Hib) was the leading cause of bacterial meningitis among children under five years old in the United States. Every year about 20,000 children under five got severe Hib disease and about 1,000 individuals died. More than half of children who developed severe Hib disease were less than 12 months of age. Since 1988, when a Hib vaccine was first introduced, the rate of Hib disease has decreased more than 99%. From 1996 through 2000, an average of about 70 children per year were reported with Hib disease.

  3. Can you get Hib disease more than once?
    Yes. A child with Hib disease may not develop protective levels of antibodies. Children less than 24 months of age who have recovered from invasive Hib disease should be considered unimmunized and receive the Hib vaccine as soon as possible.

  4. How does Hib disease spread?
    Hib disease is spread from person-to-person by direct contact or through respiratory droplets. It is not highly contagious. Usually the organisms remain in the nose and throat, but occasionally the bacteria spread to the lungs or bloodstream and cause a serious invasive disease in the infected individual.

  5. How long does it take to show signs of Hib disease after being exposed?
    The incubation period of Hib disease is unknown, but could be as short as a few days.