Pneumococcal disease is a leading cause of serious illness in children and adults throughout the world according to Dr. Jaime A. Santos when he orient the participants in the Science Writers Workshop at Manila Diamond Hotel recently. The disease is caused by a common bacterium, the pneumococcus, which can attack different parts of the body. When bacteria invade the lungs, they cause the most common form of community-acquired bacterial pneumonia; when bacteria invade the bloodstream, they cause bacteremia; and when they invade the covering of the brain, they cause meningitis. Pneumococci may also cause otitis media (middle ear infection) and sinusitis. Currently there are more than 90 known pneumococcal types; the ten most common types account for approximately 62 percent of invasive disease worldwide. Anyone can get pneumococcal disease Dr. Santos added, but some groups are at particularly high risk for pneumococcal disease or its complications. These groups include persons aged