Haemophilus influenzae type b (Hib) - including symptoms, treatment and prevention

The bacterium Haemophilus influenzae serotype b (Hib) can cause serious infection in humans. Other serotypes of Haemophilus influenzae (not type b) are found in the nose and throat of up to 80% of healthy people and can also cause infections, though they do not commonly cause meningitis (inflammation of the lining of the brain and spinal cord). (Serotype refers to groups of microorganisms that are extremely closely related, but can be distinguished by having slightly different antigens (a foreign substance which causes the body to produce antibodies) or causing the body to produce slightly different antibodies).

Hib is a notifiable condition1

How Hib is spread

The disease is spread:

  • When an infected person talks, coughs or sneezes small droplets containing infectious agents into the air. The droplets in the air may be breathed in by those nearby.
  • By indirect contact with hands, tissues or other articles soiled by nose and throat discharges.

Signs and symptoms

Before the widespread use of Hib vaccine, Hib was the most common cause of bacterial meningitis in young children in Australia.

Hib can cause a number of serious infections, including:

  • meningitis which often follows an upper respiratory infection
  • bloodstream infection (bacteraemia)
  • epiglottitis (swelling of part of the throat which may result in obstruction to breathing)
  • pneumonia (lung infection or inflammation)
  • bone and joint infections
  • cellulitis (infection of tissue beneath the skin)

Children or adults with meningitis or epiglottitis should receive urgent medical assessment.

Infants

In infants, symptoms of meningitis include:

  • fever
  • refusing feeds
  • fretfulness
  • child is difficult to wake
  • high-pitched or moaning cry
  • pale or blotchy skin
  • seizures (fits).

Older children and adults

In older children and adults, symptoms of meningitis include:

  • headache
  • fever
  • vomiting
  • stiff neck or back
  • joint pains
  • drowsiness (excessive sleepiness) or confusion
  • photophobia (discomfort when looking at light).

Epiglottitis

Symptoms of epiglottitis include:

  • fever
  • sore throat
  • dribbling (unable to swallow saliva)
  • difficulty in swallowing and breathing.

Diagnosis

Diagnosis is made by growing bacteria from the blood, CSF (cerebrospinal fluid: the fluid surrounding the brain and spinal cord) or other specimens.

Incubation period

(time between becoming infected and developing symptoms)

2 to 4 days.

Infectious period

(time during which an infected person can infect others)

As long as the bacteria are present in the nose and throat. Hib is not able to be spread after 1 to 2 days of appropriate antibiotic therapy.

Treatment

A person with a serious Hib infection should be treated in hospital with antibiotics.

Prevention

  • A child who has serious Hib infection cannot return to childcare, preschool or school until he or she has taken at least 4 days of an appropriate antibiotic course.
  • Under certain circumstances, Public Health authorities may recommend that an antibiotic such as rifampicin is given to members of a household where there is a serious Hib infection, or to staff and other children attending the same childcare centre.
  • Immunisation is routinely given to all children through the National Immunsation Program. The first dose of Hib vaccine, in combination with other vaccines, is now recommended to be given at 6 weeks of age. The Hib vaccine is also recommended for any people who have no spleen or a non-functioning spleen or who receive stem cell transplants.
  • While immunisation is highly effective in protecting young children against serious Hib infections, occasional cases still occur in vaccinated children.

Useful links

1 – In South Australia the law requires doctors and laboratories to report some infections or diseases to SA Health. These infections or diseases are commonly referred to as 'notifiable conditions'.