Nowadays in the UK, at least 95% of people with Hib meningitis recover4, but it can be fatal.
As many as one survivor in eight may be left with disabilities, that may be as severe as deafness, problems with co-ordination and epilepsy5. In many cases, after effects are temporary or improve over time. In the early stages of recovery, and especially with young children, it can be difficult to tell if problems will be long-lasting.
Other severe Hib diseases include septicaemia, epiglottitis (inflammation of the back of the throat), pneumonia, cellulitis (inflammation of tissue), osteomyelitis (bone infection), arthritis, and pericarditis (inflammation of the heart lining) 4.
Hib can also cause milder ailments like ear infections and minor respiratory illness.
How do you get Hib?
Hib bacteria are found only in humans, and live temporarily in the back of the nose and throat4.
Hib infection is spread through close contact with mucus or droplets from the throat of someone who carries the bacteria. Hib bacteria are too fragile to live outside the human body. Although we don’t know exactly how long they can survive outside, we do know that in general, prolonged close contact is necessary to pick up Hib bacteria. The majority of people who carry Hib do not become ill, which means that we are most likely to meet the bacteria through contact with perfectly healthy carriers. Before Hib vaccine was introduced, young children quite commonly carried Hib bacteria.
The incubation period for Hib is uncertain, however it is generally agreed that when Hib disease occurs, it develops within days of exposure to the bacteria1.
Who is at risk?
Only a small fraction of the people who acquire Hib bacteria fall ill with the disease and the reasons for this are not entirely understood. People with a deficient immune system, such as those without a spleen, are at higher risk. Although the disease is now rare, doctors report all cases to the Public Health doctor. Depending on their age and whether they have been vaccinated, some household contacts of a case may be more at risk than the general public. The Public Health doctor decides what action to take in these cases.
Is there a Hib vaccine?
A conjugate vaccine against Hib was introduced in the UK in 1992. Since the introduction of the Hib vaccine, meningitis caused by Haemophilus influenzae has been reduced by over 90% across the UK6. Introduction of the conjugate Hib vaccine has also dramatically reduced carriage of the bacteria7. Before the vaccine was introduced, a large proportion of children under age 5 carried the bacteria. Now that vaccination is routine, carriage of the bacteria is much less common, and as a result protection is extended to the rest of the population, even those not immunised. This is called ‘herd immunity’.