Table 2.

Mean Annual Incidence of Pneumococcal Meningitis at Eight Surveillance Sites, According to Age Group, Serotype Group, and Years (1998–2005).^*

Serotype and Age	1998–1999			2000–2001			2002–2003			2004–2005		2004–2005 vs. 1998–1999
	No. of Cases	Cases per 100,000 Persons	No. of Cases	Cases per 100,000 Persons	P Value	No. of Cases	Cases per 100,000 Persons	P Value	No. of Cases	Cases per 100,000 Persons	P Value	Relative Difference in Incidence	Absolute Difference in Incidence
												%	percentage points
All serotypes
All ages	374	1.13	372	1.06	0.42	344	0.96	0.03	289	0.79	<0.001	−30.1	−0.34
Age group
<2 yr	93	10.16	66	6.86	0.02	33	3.30	<0.001	37	3.66	<0.001	−64.0	−6.50
2–4 yr	13	0.95	23	1.63	0.13	3	0.21	0.01	13	0.87	0.85	−8.4	−0.08
5–17 yr	16	0.27	25	0.39	0.28	28	0.43	0.13	19	0.29	0.87	9.5	0.03
18–39 yr	62	0.56	55	0.47	0.41	57	0.49	0.52	46	0.40	0.10	−28.1	−0.16
40–64 yr	118	1.18	140	1.29	0.49	154	1.33	0.33	139	1.14	0.80	−3.3	0.04
≥65 yr	72	1.90	63	1.64	0.44	69	1.77	0.67	35	0.87	<0.001	−54.0	−1.03
PCV7 serotypes
All ages	220	0.66	208	0.59	0.27	109	0.30	<0.001	65	0.18	<0.001	−73.3	−0.49
Age group
<2 yr	75	8.20	44	4.57	0.002	10	1.00	<0.001	6	0.59	<0.001	−92.8	−7.60
2–4 yr	12	0.88	14	0.99	0.85	1	0.07	0.001	2	0.13	0.01	−84.7	−0.74
5–17 yr	6	0.10	14	0.22	0.12	11	0.17	0.34	6	0.09	1.00	−7.8	0.01
18–39 yr	34	0.30	21	0.18	0.06	19	0.16	0.04	11	0.10	0.001	−68.7	−0.21
40–64 yr	62	0.62	85	0.78	0.19	47	0.41	0.03	29	0.24	<0.001	−61.6	−0.38
≥65 yr	31	0.82	30	0.78	0.90	21	0.54	0.17	11	0.27	0.001	−66.5	−0.54
PCV7-related serotypes
All ages	48	0.14	50	0.14	1.00	64	0.18	0.30	36	0.10	0.08	−32.1	−0.05
Age group
<2 yr	11	1.20	7	0.73	0.35	5	0.50	0.13	2	0.20	0.01	−83.5	−1.00
2–4 yr	1	0.07	5	0.35	0.22	1	0.07	1.00	0	0.00	0.48	−100.0	−0.07
5–17 yr	0	0.00	6	0.09	0.03	2	0.03	0.50	2	0.03	0.50	—	0.03
18–39 yr	12	0.11	11	0.09	0.84	9	0.08	0.52	6	0.05	0.16	−51.6	−0.06
40–64 yr	13	0.13	11	0.10	0.55	31	0.27	0.03	22	0.18	0.40	39.0	0.05
≥65 yr	11	0.29	10	0.26	0.83	16	0.41	0.44	4	0.10	0.07	−65.6	−0.19
Non-PCV7 serotypes
All ages	106	0.32	114	0.32	0.95	171	0.48	0.001	188	0.51	<0.001	60.5	0.19
Age group
<2 yr	7	0.77	15	1.56	0.14	18	1.80	0.07	29	2.87	0.001	275.3	2.11
2–4 yr	0	0.00	4	0.28	0.13	1	0.07	1.00	11	0.74	0.001	—	0.74
5–17 yr	10	0.17	5	0.08	0.20	15	0.23	0.55	11	0.17	1.00	1.4	0.00
18–39 yr	16	0.14	23	0.20	0.34	29	0.25	0.07	29	0.25	0.07	75.6	0.11
40–64 yr	43	0.43	44	0.40	0.83	76	0.66	0.03	88	0.72	0.005	68.1	0.29
≥65 yr	30	0.79	23	0.60	0.34	32	0.82	0.90	20	0.50	0.12	−37.0	−0.29

^*The eight Active Bacterial Core surveillance sites were in California, Connecticut, Georgia, Maryland, Minnesota, New York, Oregon, and Tennessee. Serotypes of the heptavalent pneumococcal conjugate vaccine (PCV7) were 4, 6B, 9V, 14, 18C, 19F, and 23F. PCV7-related serotypes were 6A, 9A, 9L, 9N, 18A, 18B, 18F, 19B, 19C, 23A, and 23B. Non-PCV7 serotypes included 3, 7F, 10A, 11A, 12F, 15A, 15B/C, 16F, 19A, 22F, 33F, 35B, 35F, and 38. All P values are two-sided and were calculated for exact comparisons of the 2-year interval with the baseline interval (1998–1999).