Haemophilus influenzae disease is spread through contact with discharges or droplets from the nose or throat of an infected person. This disease can spread from person to person through sneezing, coughing, or speaking closely with an infected person. A person does not have to have symptoms to spread the bacterium.
The most common and severe manifestation of Haemophilus influenzae type b disease is meningitis (inflammation and swelling in the coverings of the brain and spinal cord). Symptoms of meningitis include:
- Stiff neck.
Haemophilus influenzae can also cause infection of the:
- Covering of the heart.
Symptoms depend on the part of the body affected.
The time between exposure and Haemophilus influenzae symptoms is usually less than 10 days.
Haemophilus influenzae type b disease is diagnosed by blood culture or, more often, by culture of the cerebrospinal fluid.
Unvaccinated children under age five are at risk for this disease; the disease occurs most often in children ages three months to two years.
As children grow older, they are less likely to develop Haemophilus influenzae type b disease. Very few cases occur in people over age five.