What is Haemophilus influenzae?
Haemophilus influenzae is a bacteria that is commonly found
in the nose and throat of children and adults. A particular type,
Haemophilus influenzae serotype B (Hib), can invade and cause
infections. H. influenzae may cause a variety of diseases,
including meningitis (inflammation of the coverings of the spinal
column and brain), blood stream infections, pneumonia, arthritis,
and epiglottitis. Although it was once the most common cause of
bacterial infections in children, due to widespread use of Hib vaccine
few cases are reported each year. Despite its name, this bacterium
has nothing to do with the influenza viruses.
Who gets H. influenzae infection?
Unvaccinated household and daycare contacts of people with known
H. influenzae infection are at greatest risk. Hib infection
is most common in children three months to three years of age. It
is unusual in persons over the age of five. The elderly and adults
with underlying disease are at greatest risk of non-serotype B disease.
How is H. influenzae spread?
H. influenzae may be spread through contact with mucus or
droplets from the nose and throat of an infected person
What are the symptoms of H. influenzae infection?
Symptoms of meningitis may include fever, vomiting, listlessness,
and a stiff neck or back. Other symptoms depend upon the part of
the body affected.
How soon after exposure do symptoms appear?
Symptoms generally appear in less than 10 days after exposure, commonly
within 2 to 4 days.
When and for how long is a person able to spread H.
influenzae?
The contagious period varies and, unless treated, may last for as
long as the organism is in the nose and throat, even after symptoms
have disappeared. A person can no longer spread H. influenzae
after taking the proper antibiotics for 1 to 2 days.
Does past infection with H. influenzae make a person
immune?
No. Children who have had H. influenzae infection can get
it again.
What is the treatment for H. influenzae infection?
Specific antibiotics are generally used to treat serious infections.
Should people who have been in contact with someone diagnosed
with H. influenzae infection be treated?
Preventive treatment is only recommended in specific situations.
For example, treatment with an antibiotic is recommended for household
members when there is at least one unvaccinated child under four
years of age in the home. In certain situations, preventive treatment
will be recommended in childcare centers. Casual contact such as
occurs in classrooms or office settings is not usually significant
enough for preventive treatment to be needed.
What can be done to prevent the spread of H. influenzae?
Hib vaccines are available. All children should be vaccinated against
Hib beginning at approximately two months of age. Contact your physician
or local health department for further information about vaccination.
