What is Haemophilus influenzae in children?

Haemophilus influenzae (H. influenzae) is a group of bacteria that can cause different types of infections in babies and children. H. influenzae most often cause ear, eye, or sinus infections. They also cause pneumonia.

A strain of the bacteria that causes more serious disease is called H. influenzae type b (Hib). The type b strain is now rare in the U.S. because of the Hib vaccine. Before widespread vaccination, significant disease occurred in as many as 130 out of 100,000 kids. That rate is now less than 1 out of 100,000 children. The type b strain caused many cases of infection of the membranes that surround the brain (meningitis). It also caused a life-threatening infection called epiglottitis. This is infection of the part of the throat that covers and protects the voice box (larynx) and windpipe (trachea) while swallowing. In rare cases, a child may still get an Hib infection. This is more likely to occur in a child who hasn't finished the series of vaccines. Or it can occur in an older child who didn't get the vaccine as a baby. Children who travel to other countries may also be at risk. This is because not all children around the world get the Hib vaccine. Most cases of H. influenzae that occur today are due to the non-type b strains of the bacteria.

What causes H. influenzae in a child?

The H. influenzae bacteria live in the nose, sinuses, and throat. They are often spread by close contact with an infected person. Droplets in the air from a sneeze or cough can be breathed in. These may also cause infection.

What are the symptoms of H. influenzae in a child?

Symptoms can be a bit different for each child. Below are the most common symptoms.

Middle ear infection (otitis media)

This may occur after a child has a common cold caused by a virus. Symptoms may include:

Abnormal irritability
Trouble sleeping or staying asleep
Tugging or pulling at one or both ears
Fever
Fluid draining from an ear or ears
Loss of balance
Hearing problems
Ear pain
Loss of appetite

Conjunctivitis

This is an inflammation of the conjunctiva of the eye. The conjunctiva is the membrane that lines the inside of the eyelid and also a thin membrane that covers the eyeball. Symptoms may include:

Eye redness
Swelling
Fluid from one or both eyes
Burning feeling of the eyes
Eyes sensitive to light (photophobia)

Sinusitis

This is an infection of the sinuses. Symptoms in younger children may include:

Runny nose that lasts longer than 10 to 14 days and nasal fluid may become thick green, yellow, or blood-tinged
Nighttime cough
Occasional daytime cough
Swelling around the eyes

Symptoms of sinusitis in older children may include:

Runny nose or cold symptoms that last longer than 10 to 14 days
Nasal fluid that drains down the back of the throat (postnasal drip)
Headache
Pain over the cheekbones or over the eyes that’s worse when leaning over (sinus pain)
Bad breath
Cough
Fever
Sore throat
Swelling around the eye that’s worse in the morning

Epiglottitis

This is an infection of the part of the throat that covers and protects the voice box and windpipe when swallowing. Epiglottitis is a medical emergency. It can be fatal if not treated rapidly. Due to the Hib vaccine, epiglottitis is very rare in children and babies.

Symptoms may include:

Suddenly getting a very sore throat
Fever
Muffled voice
No cough
Shortness of breath

As the infection gets worse, symptoms may include:

Drooling
Inability to talk
Leaning forward while sitting
Breathing with mouth open
Trouble breathing

Meningitis

This is an infection of the membranes that surround the brain and spinal cord. Because of the vaccine, meningitis caused by H. influenzae is very rare in children and babies. Symptoms in children older than 1 year may include:

Neck or back pain, especially when moving the chin toward the chest
Headache
Upset stomach and vomiting
Neck stiffness
Eyes sensitive to light

In babies, symptoms are more general and may include:

Irritability
Sleeping all the time
Feeding problems, such as refusing a bottle
Crying when picked up or being held
Crying that won’t stop
Bulging soft spot (fontanelle)
Behavior changes
Fever
Not bending the neck when moving or playing with a toy

Many of these symptoms may be caused by other health problems. Have your child see their healthcare provider for a diagnosis.

How is H. influenzae diagnosed in a child?

The healthcare provider will ask about your child’s symptoms and health history. They will give your child a physical exam. Your child may also have tests, such as:

Testing of a small sample of fluid from the eye, ear, blood, or spinal canal to check for signs of the bacteria
Blood tests to check for signs of the bacteria
Chest or neck X-ray

How is H. influenzae treated in a child?

Antibiotics are used to treat infections caused by H. influenzae. The length of treatment varies depending on where the infection is and how serious it is. Other treatment is done to ease symptoms. Talk with your child’s healthcare provider about the risks, benefits, and possible side effects of all medicines.

How can I help prevent H. influenzae in my child?

Vaccines against H. influenzae type b are routinely given in a 3- or 4-part series. The vaccine is often called the Hib vaccine. The first doses are given at ages 2 and 4 months or at ages 2 months, 4 months, and 6 months. A booster is then given between ages 12 and 15 months. If a child at average risk hasn't had the vaccine and is older than 5 years, they do not need to be vaccinated. The vaccine may be recommended for older children with conditions that put them at higher risk, such as:

Sickle cell disease
No spleen (asplenia)
A weak immune system from cancer or following a bone marrow transplant
HIV

When should I call my child’s healthcare provider?

Call the healthcare provider if your child has:

Symptoms that don’t get better, or get worse
New symptoms

Key points about H. influenzae in children

Haemophilus influenzae (H. influenzae) is a group of bacteria that can cause different types of infections in babies and children.
H. influenzae most often cause ear, eye, or sinus infections. They also cause pneumonia.
A more serious strain of the bacteria, called H. influenzae type b (Hib), is rare in the U.S. because of the Hib vaccine.
The H. influenzae bacteria are often spread by close contact with an infected person. Droplets in the air from a sneeze or cough can be breathed in and may also cause infection.
Antibiotics are used to treat infections caused by H. influenza.
Vaccines against Hib are routinely given to children.

Next steps

Tips to help you get the most from a visit to your child’s healthcare provider:

Know the reason for the visit and what you want to happen.
Before your visit, write down questions you want answered.
At the visit, write down the name of a new diagnosis, and any new medicines, treatments, or tests. Also write down any new instructions your provider gives you for your child.
Know why a new medicine or treatment is prescribed and how it will help your child. Also know what the side effects are and when they should be reported.
Ask if your child’s condition can be treated in other ways.
Know why a test or procedure is recommended and what the results could mean.
Know what to expect if your child does not take the medicine or have the test or procedure.
If your child has a follow-up appointment, write down the date, time, and purpose for that visit.
Know how you can contact your child’s provider after office hours, and on weekends and holidays. This is important if your child becomes ill and you have questions or need advice.

Haemophilus Influenzae Infections in Children