Streptococcus pneumoniae , or pneumococcus , is a bacteria that causes many different kinds of infections in people, ranging from ear infections and sinus infections to pneumonia, meningitis , and sepsis .
Many people have pneumococci in their noses and throats but have no symptoms.
The bacteria is transmitted from one person to another, usually by droplets. Like viral upper respiratory infections, pneumococcal infections are more common in winter. Infection can begin as little as 1-3 days after exposure. The signs of pneumococcal meningitis and sepsis can be the same as those of meningococcal meningitis. There are also some people who are more susceptible to pneumococcal infections than others.