The bacteria can be spread from person to person through respiratory droplet spread or indirectly through contact with articles soiled with respiratory discharges. In infants, vomiting and convulsions may be the first indication of infection. S. pneumoniae is the third leading cause of bacterial meningitis in the United States, most cases are in children under 5 years of age. Meningitis can develop from untreated middle ear or sinus infections, pneumonia, or bacteremia. Bacterial meningitis is seen as an acute onset of high fever, headache, vomiting, drowsiness, and stiff neck.
Illness progresses rapidly causing loss of consciousness and possibly death.
Symptoms may appear in 1-3 days from infection. People with normal immune systems may develop antibodies specific to each serotype of pneumococci which, in general, persist for life. Clinical observation of the symptoms accompanied by laboratory cultures from blood and other body fluids and a high white blood cell count in people with normal immune systems. Chest x-rays are important diagnostic tools when pneumonia is suspected. Penicillin is the drug of choice.