Haemophilus influenzae

Most commonly, haemophilus influenza type b or Hib disease

Haemophilus influenzae is the name of a group of bacteria that can cause mild to very serious illness, particularly in children under the age of 5 years. The most common is haemophilus influenza type b or Hib, so the information on this page is mainly about Hib disease. It’s important to know when you or your child may have Hib disease and what to do about it.

Key points

  1. There are 6 types of haemophilus influenzae bacteria (Hia through to Hif). They can cause a range of illnesses affecting your breathing, joints, bones and nervous system. Some of these illnesses can cause lifelong disability or death.
  2. The most common type, haemophilus influenzae type b (known as Hib), causes 95% of all cases of serious haemophilus influenzae disease (Hib disease).
  3. Haemophilus influenzae does not cause influenza (the flu). It causes infections that range from mild ear infections to serious bloodstream infections or meningitis.
  4. Haemophilus influenzae bacteria is easily spread from person to person through direct contact or by sneezing and coughing.
  5. If you are living with an infected person you may need to take antibiotics to prevent you catching the disease.
  6. Vaccination is the best way to protect yourself or your child against Hib disease. All babies in New Zealand can be vaccinated against Hib disease as part of their free childhood vaccinations at 6 weeks, 3 months, 5 months and 15 months old.
Act quickly!  If you have a baby who is sick with sudden fever, shaking/chills, cough, shortness of breath, chest pain, stiff neck, disorientation and sensitivity to light take action immediately. Urgent hospital care is usually needed as babies can get very sick very quickly.

What is Hib disease?

Haemophilus influenzae bacteria live in the nose and throat of most healthy people without causing illness. The bacteria are easily passed from person to person by coughing, sneezing and close contact. Not everyone who catches or carries the bacteria gets sick. If the bacteria get into other parts of your body, it can cause infection. The infections can range from minor ear infections to serious diseases, such as bloodstream infections. Infections include:

  • pneumonia (infection of the lung)
  • meningitis (infection of the covering of the spinal cord and brain)
  • epiglottitis (windpipe inflammation; this can lead to trouble breathing)
  • osteomyelitis (infections of your bones and joints)
  • bacteremia (blood infection)
  • cellulitis (skin infection).

The time between exposure and feeling symptoms (incubation period) of haemophilus influenzae disease is uncertain, but may be as little as just a few days.

Who is most at risk of getting Hib disease?

Haemophilus influenzae bacteria are common but not everyone who has them will get sick. Those most at risk of serious disease are children under 5 years and people who have a weakened immune system. Being in daycare, having school-aged brothers and sisters, and living with lots of other people can also increase your risk of getting Hib disease.

What are the symptoms of Hib disease?

The symptoms of Hib disease are not the same for everyone. The symptoms vary depending on where the infection is. A baby or young child may only have fever and be irritable. Find out about the symptoms of the following conditions that can be caused by Hib:

  • ear infection
  • meningitis
  • pneumonia
  • osteomyelitis.

Meningitis and epiglottitis can develop quickly and can rapidly cause death if left untreated. You need to see a doctor immediately for treatment.

  • About 1 in 20 patients with meningitis die and 1 in 3 survivors has permanent brain or nerve damage.
  • About 1 in 100 patients with epiglottitis die.

How is Hib disease diagnosed and treated?

Your doctor will diagnose and treat Hib disease based on your symptoms and test results. Read about the diagnosis and treatment of conditions caused by Hib disease:

How can I prevent Hib disease?

Vaccination of babies and those at increased risk due to underlying medical conditions can greatly help to prevent Hib disease and bacterial spread. It is very difficult to avoid coming into contact with the bacteria that cause this illness, so as well as being vaccinated you can reduce your chances of becoming infected or infecting others by:

  • regularly washing your hands with soap and water or an alcohol-based hand gel
  • covering your nose and mouth with your arm or a tissue when you cough or sneeze.

Why is vaccination so important?

Babies and young children are at particular risk of infection because their immune system is not fully developed. They can be protected, however, by being vaccinated against Hib disease. Hib disease has been almost eliminated in countries where Hib vaccine is used. Vaccination against Hib disease is free as part of the National Immunisation Schedule in New Zealand for babies at 6 weeks, 3 months, 5 months and 15 months of age.

  • If your baby misses these dates, they can have catch-up vaccinations. Talk to your doctor or nurse about this.
  • The vaccine is given by injection in your arm or leg.
  • Children and adults with medical conditions that increase their risk of Hib disease are eligible for funded vaccination against Hib.

Learn more

Haemophilus influenzae type b disease The Immunisation Advisory Centre, 2017
Haemophilus influenzae type b (Hib) Ministry of Health, NZ, 2017
Prevention – making a decision about vaccination Ministry of Health, NZ, 2017


  1. Childhood immunisation HealthEd, NZ
  2. Haemophilus influenzae type b disease Immunisation Handbook, NZ, 2017
Credits: Editorial team. Last reviewed: 11 Dec 2017