Streptococcus pneumoniae is a Gram-positive, alpha-hemolytic, facultative anaerobic coccus. It is the most common cause of community acquired pneumonia in adults and infants, and a major cause of morbidity and mortality. It is also a frequent cause of otitis media and sinus infections. It spreads through close person-to-person contact via respiratory droplets. It presents as pneumonia, bacteremia, or meningitis.