(Invasive pneumococcal disease)
Streptococcus pneumoniae is a bacterium that is most often associated with mild illness, such as ear and sinus infections. It may also cause life-threatening invasive disease, like pneumonia, sepsis (bloodstream infection), and meningitis (inflammation of the tissues that cover the brain and spinal cord). These types of illness are most common in babies, children under 5 years of age, the elderly, and people with weakened immune systems.
Streptococcus pneumoniae is considered "invasive" when it is found in the blood, spinal fluid or other normally sterile sites.