Risk factors for invasive pneumococcal disease

Worldwide, Streptococcus pneumoniae is a pathogen isolated frequently during respiratory infections and more life-threatening, invasive infections such as sepsis and meningitis. Despite the use of antibiotics, invasive pneumococcal disease (IPD) leads to substantial mortality and morbidity. The most promising prospect for preventing IPD is by vaccination. Vaccination programmes rely largely on the knowledge of the risk factors and definition of subpopulations at increased risk for IPD. Many epidemiological studies have provided evidence that several factors increase the risk of acquiring IPD. Infections due to pneumococci are strongly age-related and are most frequently observed in infants and the elderly. In the adult population a variety of underlying medical conditions and socio-economic factors are found to play an important role. In the present review we offer an overview of the currently known risk factors of IPD for neonates, children, adults and the elderly. In addition, different underlying conditions associated with an increased risk of acquiring IPD will be discussed. (C) 2002 Lippincott Williams Wilkins.