Table 1.

Carriage and Invasive Pneumococcal Disease Study Characteristics, Navajo and White Mountain Apache Populations, United States, 1995–2012

Age, years	Perioda	Datesb	Colonization				No. of IPD Cases	Reference No.c
			No. of Participants	Total No. of Swabs	No. of Positive Swabs	%
<7
	1	June 1995–June 2000	411	1,077	684	63.5	252	20
	2	July 2000–June 2004	1,914	1,918	1,185	61.8	117	19
	3	July 2004–June 2010	549	3,329	1,835	55.1	132	18
	4	July 2010–December 2012	3,259	3,259	1,686	51.7	22
18–39
	1	June 1995–June 2000	N/A	N/A	N/A	N/A	116	N/A
	2	July 2000–June 2004	1,494	1,507	180	11.9	56	19
	3	July 2004–June 2010	373	2,199	240	10.9	96	18
	4	July 2010–December 2012	2,307	2,307	277	12.0	24	N/A
≥40
	1	June 1995–June 2000	N/A	N/A	N/A	N/A	311	N/A
	2	July 2000–June 2004	500	504	48	9.5	205	19
	3	July 2004–June 2010	67	427	41	9.6	418	18
	4	July 2010–December 2012	399	399	37	9.3	110	N/A

Abbreviations: IPD, invasive pneumococcal disease; N/A, not applicable.

^a Carriage data were collected as part of a randomized controlled trial, and only data from the control group (who did not receive pneumococcal conjugate vaccine serotype 7) were included in this analysis.

^b Date ranges denote when the disease isolates were collected. Carriage isolates were collected over shorter periods of time within these windows (1998–2000, 2001–2002, 2006–2008, and 2010–2012).

^c Carriage data from period 4 are unpublished.