About Haemophilus influenzae Disease

Key points

  • Bacteria called Haemophilus influenzae can cause many types of infections.
  • Some of these infections are mild, while others are serious.
  • In spite of its name, H. influenzae doesn't cause the flu.
  • Vaccines can prevent infections from one type of H. influenzae, type b or Hib.
Mother checks daughter's temperature.

What it is

H. influenzae disease is a name for any infection caused by H. influenzae bacteria.

An image of Haemophilus influenzae that was generated by a computer based on scanning electron microscopic imagery.
This image of Haemophilus influenzae was computer generated.

Types

H. influenzae can cause many different types of infections. These infections range from mild, like ear infections, to serious, like bloodstream infections.

Serious infections

The most common serious infections caused by H. influenzae are:

  • Pneumonia (a lung infection)
  • Bloodstream infection
  • Meningitis (swelling of the lining of the brain and spinal cord)
  • Epiglotittis (swelling of the throat)
  • Cellulitis (skin infection)
  • Infectious arthritis (swelling of the joint)

Mild infections

H. influenzae are a common cause of ear infections in children and bronchitis (chest cold) in adults.

Symptoms

H. influenzae can cause many different types of infections. Symptoms depend on the part of the body that's infected. Serious infections can result in long-term health problems and death.

Risk factors

People of certain ages and racial or ethnic groups are at increased risk for H. influenzae disease. Some medical conditions can also increase someone's risk.

Keep Reading: Risk Factors

Causes

H. influenzae are bacteria that live in people's nose and throat. Usually, these bacteria cause no harm. However, they can move to other parts of the body and cause infection.

Did you know?‎

There are 6 types of H. influenzae. They are named a through f. The one that most people are familiar with is H. influenzae type b or Hib.

Spread to others

People spread H. influenzae to others by coughing or sneezing, which creates small respiratory droplets that contain the bacteria. Other people can get infected if they breathe in those droplets.

People who aren't sick but have the bacteria in their nose and throat can still spread the bacteria. That's how H. influenzae spreads most of the time.

The bacteria can also spread to people who have close or lengthy contact with a person with H. influenzae disease.

Prevention

People can get H. influenzae, including Hib, disease more than once. Maintaining healthy habits, like washing hands often and not having close contact with people who are sick, helps prevent H. influenzae disease.

Vaccination

Vaccines can prevent Hib disease, but not disease caused by other types of H. influenzae. The best way to prevent Hib disease is to get vaccinated. CDC recommends Hib vaccines for all children younger than 5 years old.

Keep Reading: Hib Vaccination

Antibiotics

Sometimes close contacts of someone with Hib disease should receive antibiotics to prevent them from getting sick. A healthcare provider or health department generally decides who should get preventive antibiotics.

Testing and diagnosis

Healthcare providers usually diagnose H. influenzae disease with one or more lab tests. The most common testing methods use a sample of blood or spinal fluid.

Treatment and recovery

People diagnosed with H. influenzae disease take antibiotics to treat the infection.

People with serious infections may need care in a hospital. Other treatments may include:

  • Breathing support
  • Medicine to treat low blood pressure
  • Wound care for parts of the body with damaged skin