When a friend of mine was a small child, she woke up in the middle of the night, unable to breathe. She managed to wake up her parents, who called the ambulance. Another friend of mine, who was working on the ambulance that night, saved her life by doing an emergency tracheostomy. In other words, he cut a hole in her throat for her to breathe through. It was a horrifying experience for everyone involved. The likely cause of the problem was an infection called Haemophilus influenza type B, or Hib. Hib infections are the main cause of epiglottitis, which is swelling of the flap that closes off the windpipe when you swallow. Thanks to the vaccine against Hib, the incidence of Hib infections in the United States has gone down by more than 99%. As a result, today’s young doctors will never see a case of epiglottitis in their career.
Haemophilus influenzae type b
Haemophilus influenzae, or Pfeiffer’s bacillus, is a bacterium that lives in the upper respiratory tract of human beings. It was once thought to be the cause of influenza (the flu). But now we know that influenza is the result of a viral infection.
Many of the strains of H. influenza have a capsule that helps the bacteria hide from the body’s immune system. These strains are sorted into 6 different types (types a through f), according to the polysaccharides found in their capsules. Many of the strains of H. influenzae can cause upper respiratory infections, such as sinus infections. However, the type b strains (which are called Hib) can cause a serious infection that runs throughout the body. Sometimes, it can even get into the fluid surrounding the brain. This problem is called meningitis because it causes inflammation of the meninges, which are the membranes that cover the brain. This form of meningitis is a medical emergency that can kill within hours. Here is the story of one family whose unvaccinated son caught Hib. He is lucky to have survived:
This family was not so lucky.
Thanks to the Hib vaccine, Hib infection is now rare, as this report from Canada explains: