Haemophilus influenzae B (Hib) disease
Tell me more about Hib disease.
Haemophilus influenzae type B colonizes the respiratory tracts of many healthy people without causing disease. The B subtype of Haemophilus influenzae is more virulent than the other subtypes because it is surrounded by a polysaccharide (carbohydrate) capsule that allows it to evade capture by the immune system. When Hib does cause disease, it can cause meningitis, bacteremia, and other invasive disease. Since the approval of the Hib conjugate vaccine, meningitis caused by Hib has declined more than 95% in children under the age of 5.
How is Hib transmitted?
A person who is uninfected and/or uncolonized with Hib can catch the bacteria from the respiratory secretions from an infected person or carrier.
It is unknown how a carrier may develop Hib disease.
What are the symptoms of Hib disease?
The disease symptoms caused by Hib vary by the site of infection. For meningitis, the most common site of infection by Hib, the symptoms include:
- Stiff neck
If a person develops Hib infection of the blood (bacteremia or sepsis), they may have the following symptoms:
How is Hib treated?
Because Hib is a bacterial disease, antibiotics are effective in treating Hib infections. In the case of invasive disease, such as meningitis or sepsis, intravenous antibiotics may initially be used, followed by oral antibiotics. In other cases, oral antibiotics will be used for the entire course of treatment. Most cases of Hib are now resistant to antibiotics such as ampicillin, and therefore different, more expensive and more toxic antibiotics need to be used to treat Hib disease.
How can I prevent Hib disease?
As of 1996, there has been a safe and effective vaccine against Hib disease. Therefore, the most important thing you can do is to have your child vaccinated against Hib. The conjugate vaccine is effective in infants, and children can begin the Hib vaccine series at 2 months of age. A total of 2-3 doses is required, depending on the vaccine manufacturer, as well as a booster at 12-15 months. Older children and adults may require a shorter series of vaccine.
The antibiotic rifampin may be used as prophylaxis to treat unvaccinated contacts of persons with invasive Hib disease, although this remains controversial. It is best to consult with the Monroe County Health Department or your physician to determine the best course of action.
"Pink Book on Immunization" chapter on Haemophilus influenzae B:
CDC Info on Haemophilus Influenzae B (Hib):