Risk Factors

Conditions that increase the risk of invasive pneumococcal disease among adults include:

• Decreased immune function from disease or drugs
• Functional or anatomic asplenia
• Chronic heart, lung (including asthma), liver, or renal disease
• Cigarette smoking
• Cerebrospinal fluid leak or cochlear implant

Children with functional or anatomic asplenia, particularly those with sickle cell disease, and children with HIV infection are at very high risk for invasive disease. Some studies report rates more than 50 times higher than those among children of the same age without these conditions.

Children of certain racial and ethnic groups, in particular Alaska Natives, African American, and certain American Indian groups also have increased rates of disease. CDC does not know the reason for this increased risk by race and ethnicity with certainty but it was also noted for invasive Haemophilus influenzae infection (which is also caused by an encapsulated bacterium).

Research shows that attendance at a childcare center increases the risk of invasive pneumococcal disease and acute otitis media 2–3-fold among children younger than 59 months old.