The bacteria called Haemophilus are a small gram negative bacillus which is normally found in the throat and nasal passages of a large percentage of adults. According to Elmer Koneman, M.D., prior to the availability of the Haemophilus influenzae type B vaccine in 1985, as many as 60 percent of children in daycare centers were colonized with the bacterium in the throat.
Meningitis
The most serious complication of Haemophilus infection is meningitis. Before the Haemophilus influenzae B vaccine, this was the most common cause of bacterial meningitis in children between 1 month and 2 years of age.
Infection of the spinal fluid usually begins with prior nasal colonization in a susceptible person which leads to invasion of the bloodstream and eventually the spinal fluid. Many cases of Haemophilus meningitis follow upper respiratory and ear infections.
Symptoms usually occur abruptly in children with fever, malaise, and vomiting. More serious complications may include seizures and brain abscess.
Adults with certain underlying conditions, such as HIV, diabetes and alcoholism, may be susceptible to Haemophilus meningitis.
Epiglottitis
Epiglottitis is most frequently caused by Haemophilus influenzae type B. It is a swelling of the epiglottis, which is located above the throat at the base of the tongue. When infected and swollen, this can cause life threatening obstruction and respiratory distress.
This complication of Haemophilus infection is typically seen in children ages 2 to 7 years but may also be seen in adults. The complication of epiglottitis has decreased since the availability of Haemophilus influenzae B vaccine.
Ear Infections
Ear infections, particularly middle ear infections (otitis media) caused by Haemophilus occur most frequently in children 6 months to 5 years of age. It being common in children is likely due to development of the Eustachian tube at that age.
Symptoms of ear infections caused by Haemophilus include ear pain, fever, hearing loss, and nausea and vomiting. The ear drum can be red and bulging with occasional discharge.
Pink Eye
This is an extremely common complication of Haemophilus infection. It can involve different parts of the eye, with conjunctivitis "pink eye" being most common. Because it is so easily transmissible, outbreaks of pink eye are common among people that share towels, handkerchiefs and other objects that come into contact with the face or the eyes.
Conjunctivitis caused by Haemophilus is characterized by a diffuse pink color in the whites of the eye and the presence of a discharge.
References
- "Koneman's Color Atlas and Textbook of Diagnostic Microbiology", Elmer Koneman, M.D., 2006
- National Network for Immunization Information
- CDC: Haemophilus influenzae vaccine
