ASSOCIATION OF INVASIVE PNEUMOCOCCAL DISEASE WITH SEASON, ATMOSPHERICCONDITIONS, AIR-POLLUTION, AND THE ISOLATION OF RESPIRATORY VIRUSES

We examined the relation of invasive pneumococcal disease to season, a tmospheric conditions, and the rate of respiratory virus isolation in a community-wide surveillance program in Houston, Among adults, the nu mber of cases of pneumococcal bacteremia peaked in midwinter and decli ned strikingly in midsummer, indicating a high degree of inverse corre lation with the ambient temperature, We detected significant correlati ons between the occurrence of pneumococcal disease and the isolation o f respiratory syncytial virus (P < .001), influenza virus (P < .001), and all viruses except influenza virus (P < .001), as well as with air pollution, as measured by SO2 levels (P < .001). In contrast, the rat e of invasive pneumococcal disease among infants and children was rela tively more sustained from October through May, with a notable decreas e in summer months; the incidence of pneumococcal disease was therefor e less strongly correlated with cold weather and less closely associat ed with the isolation of respiratory syncitial virus or influenza viru s, However, pneumococcal disease among infants and children was associ ated with isolation of these viruses after a 4-week lag period as well as with isolation of adenovirus and ragweed pollen counts. The findin g, with regard to children, that correlations tended to be stronger fo r events that occurred 1 month previously than for those that occurred contemporaneously is consistent with the concept that viral or allerg ic events predispose to otitis media with effusion, which becomes supp urative and leads to pneumococcal bacteremia or meningitis, For adults , a more immediate predisposition to pneumococcal pneumonia and bacter emia because of viral infection or air pollution was suggested.