Haemophilus influenzae

Haemophilus influenzae disease is caused by a bacteria which used to be found in the nose and throat region of almost every child before the Hib vaccine was discovered. H. influenzae as the name sounds  does not cause influenza or flu. Serious diseases caused by it can actually make the victim disabled for life and can be even fatal. It is caused by the bacterium Haemophilus influenzae, which are of various types. Haemophilus influenzae type b or Hib is responsible for more than 90% of systemic infections. It mainly affects children younger than 5 years of age. H. influenzae bacteria most commonly cause pneumonia, which is a lung infection. H. influenzae bacteria, including Hib can cause many kinds of infections which can range from mild ear infections to severe invasive infections which can be even fatal. Invasive infections  are caused due to bacteria travelling to sterile or germ free zones of the body. The most common types of invasive H. influenzae diseases are:

  • Bacteremia (infection of the blood)
  • Meningitis (infection of the covering of the brain and spinal cord can cause permanent deafness and brain damage)
  • Epiglottitis (an inflammation and swelling of the windpipe can block breathing)
  • Cellulitis (skin infection)
  • Infectious arthritis (inflammation of the joints)

Meningitis, Epiglottitis and Pneumonia are the life threatening diseases caused by Hib andare vaccine preventable.

How is H. influenzae spread?

Haemophilus influenzae bacteria, including Hib, are spread from one person to another by direct contact or through air contaminated from coughing and sneezing by infected persons. The disease can be spread by people who are not sick or do not show the symptoms of disease, but just carry the bacteria in their noses and throats. People get sick as soon as they come in contact with the bacteria. Hib Vaccine can prevent disease caused by Haemophilus influenzae type b (Hib), but not the other types of Haemophilus influenzae bacteria.