Haemophilus influenzae Type B

What is Haemophilus influenzae type b (Hib) disease?

Haemophilus influenzae is a type of bacteria that is commonly found in the nose and throat. Haemophilus influenzae serotype b (Hib), can invade the body and cause serious infections. Hib may cause different types of infection including:

• Meningitis (inflammation of the lining of the spinal column and brain),
• Bloodstream infection
• Pneumonia (a lung infection)
• Arthritis (swelling of the joint)
• Infections in other parts of the body

Despite its name, this disease has nothing to do with the influenza (flu) virus.

Who gets Hib?

Hib disease can occur at any age. Hib was once the leading cause of bacterial meningitis among young children. However, there are few childhood cases now due to widespread use of Hib vaccination. Hib disease is more common in unimmunized or incompletely immunized children, especially those less than five years of age. It also occurs in people with weakened immune systems.

How is Hib spread?

People spread Hib disease to others by coughing or sneezing, which creates small respiratory droplets that contain the bacteria. People who aren’t sick but have the bacteria in their nose and throat can still spread the bacteria.

What are the symptoms of Hib disease?

Symptoms depend on the part of the body that’s infected. Serious infections causing meningitis, pneumonia, and bloodstream infections can result in long-term health problems and death. Complications aren’t common for mild infections. Mild infections may cause ear infections or bronchitis.

How soon after exposure do symptoms appear?

Symptoms generally appear in less than 10 days after exposure and more commonly within 2–4 days.

How is Hib diagnosed?

Laboratory testing is needed to confirm that a person has been infected with Hib. The most common testing methods use a sample of blood or spinal fluid.

How long can a sick person carry Hib disease?

The contagious period varies and, unless treated, may last as long as the bacteria is in the nose and throat, even after symptoms disappear. A person can no longer spread Hib disease after taking the proper antibiotics for 1–2 days.

What is the treatment for Hib?

People diagnosed with Hib take antibiotics to treat the infection. People with serious infections may need care in a hospital.

Do people who have been in contact with someone with Hib infection need to be tested and treated?

Sometimes close contacts should receive antibiotics to prevent them from getting sick. This may include people that live in the same household or attend the same childcare. Preventative antibiotics can reduce the risk of infection after an exposure. A healthcare provider or health department generally decides who should get preventative antibiotics.

How can Hib disease be prevented?

The best way to prevent Hib disease is to get vaccinated. All children younger than five years old are recommended to receive the Hib vaccine. Multiple doses are needed to ensure protection. Some older children and adults with weakened immune systems are at increased risk for infection and may be recommended to get the Hib vaccine. Talk to a healthcare provider if you have questions about Hib vaccines.

How can I get more information about Hib disease?

• If you have concerns about Hib, contact your healthcare provider.
• Contact your local health department.
• Visit the CDC Haemophilus influenzae Disease page.