Volume 9, Number 5—May 2003
Research
Seasonal Patterns of Invasive Pneumococcal Disease
Scott F. Dowell*†
, Cynthia G. Whitney†, Carolyn Wright†, Charles E. Rose†, and Anne Schuchat†
, Cynthia G. Whitney†, Carolyn Wright†, Charles E. Rose†, and Anne Schuchat†Table
Characteristics of persons with invasive pneumococcal disease during an annual winter spike in incidence compared with those experiencing invasive pneumococcal disease during the surrounding weeks, 1996–1998.a
| Characteristic | Percentage of patients with characteristic |
p valueb | |
|---|---|---|---|
| Nonspike (N=1,647) | Spike (N=1,351) | ||
| Sex (% male) |
54.9 |
51.4 |
0.07 |
| Race (% white) |
56.6 |
60.8 |
0.07 |
| Age (% adult) |
74.3 |
81.7 |
0.0000013 |
| Survival |
87.1 |
87.5 |
0.92 |
| State |
0.49 |
||
| California |
6.0 |
4.9 |
– |
| Connecticut |
17.7 |
18.9 |
– |
| Georgia |
25.6 |
25.3 |
– |
| Maryland |
20.2 |
19.1 |
– |
| Minnesota |
10.4 |
11.3 |
– |
| Oregon |
6.8 |
5.8 |
– |
| Tennessee |
13.3 |
14.7 |
– |
| Syndrome |
0.24 |
||
| Bacteremia |
35.6 |
33.0 |
– |
| Pneumonia |
56.4 |
59.6 |
– |
| Meningitis | 4.9 | 4.6 | – |
aThe spike period was defined as December 20–January 10 of each year, and the nonspike periods were December 1–19 and January 11–31.
bp value calculated by chi-square test of the 2 x N table, with Yates correction.
