Pneumococcal disease is an infection caused by a type of bacteria called Streptococcus pneumoniae (pneumococcus). There are different types of pneumococcal disease, such as pneumococcal pneumonia, bacteremia, meningitis, and otitis media.

The symptoms of pneumococcal pneumonia include fever, cough, shortness of breath, and chest pain. The symptoms of pneumococcal meningitis include stiff neck, fever, mental confusion and disorientation, and visual sensitivity to light (photophobia). The symptoms of pneumococcal bacteremia (a bloodstream infection) may be similar to some of the symptoms of pneumonia and meningitis, along with joint pain and chills. The symptoms of otitis media (middle ear infection) typically include a painful ear, a red or swollen eardrum, and sometimes sleeplessness, fever and irritability.

Pneumococcus (a type of bacteria) is in many people's noses and throats and is spread by coughing, sneezing, or contact with respiratory secretions. Why it suddenly invades the body and causes disease is unknown.