Pneumococcal infections and adult with risk factors.

Streptococcus pneumoniae is an important bacterium in humans, and is a cause of upper and lower respiratory tract infections, meningitis, bacteremia, and/or invasive infections. An analysis of literature allows identifying the main risk factors; spleen dysfunctions, sickle cell anemia, alcohol abuse, chronic liver disease, cirrhosis, ischemic cardiac diseases, congestive cardiac failure, diabetes mellitus, obesity, chronic lung disease, immunodeficient patients including HIV infection, and old age. S. pneumoniae infections are more frequent and more severe in these patients. The pathophysiological mechanisms involved may be associated. These populations at risk should receive anti-pneumococcal vaccination. The availability of a 13 valent conjugate vaccine for adult opens new perspectives, but its clinical effectiveness needs to be proved for these patients at risk.