Invasive pneumococcal infection in Baltimore, Md - Implications for immunization policy

Background: Streptococcus pneumonicae is a leading cause of infectious morb idity and mortality. Although blacks are known to have a higher incidence o f invasive pneumococcal infection than whites, detailed analyses of these d ifferences and their implications for vaccine prevention have not been repo rted. Objective: To describe the epidemiological characteristics of invasive pneu mococcal infection in Baltimore, Mdl and its implications for immunization policy. Methods: Analysis of active, laboratory-based surveillance during 1995 and 1996 among residents of the Baltimore metropolitan area. Results: Of 1412 cases, 615 patients (43.6%) were classified as white and 7 66 (54.2%) as black. The annual incidence of invasive pneumococcal infectio n among white and black residents of the Baltimore metropolitan area was 17 .8 and 59.2 per 100 000 population, respectively (P<.01). Among patients ag ed 18 years and older, the median age of blacks with invasive pneumococcal infections was 27 years younger than that of whites (P<.01). Among males 40 to 49 years old, blacks had a 12-fold higher average incidence than whites (average incidence, 114.5 and 9.3, respectively; P<.01). By the age of 65 years, 83.8% of cases had occurred in black adults, as compared with 43.8% in white adults (P<.01). In a regression model, age, black race, male sex, low median family income, and county prevalence of acquired immunodeficienc y syndrome were each independently associated with a higher incidence of pn eumococcal infection. Conclusions: Young urban black adults in the Baltimore metropolitan area ha ve a dramatically higher incidence of invasive pneumococcal infection than whites. The vast majority of cases of invasive pneumococcal infection in bl acks occur before age 65 years. Current immunization efforts have not addre ssed the high incidence of pneumococcal infection in this population.