. 2014 Jan 17;9(1):e79578. doi: 10.1371/journal.pone.0079578

Table 2. Summary of pneumococcal acquisition events by age category.

	Age category
	<2 years		2–4 years		5–8 years		17–39 years		40–64 years		≥65 years		All ages
Swabs obtained (#)	1447		1379		1035		2233		376		58		6541
Total # isolates ^a (#, per-swab probability)	835	0.577	787	0.571	502	0.486	249	0.111	36	0.096	8	0.138	2417	0.37
Individual acquisitions ^a (#,per-swab probability)	369	0.301	426	0.367	285	0.326	151	0.078	21	0.065	5	0.098	1257	0.227
New acquisitions^b (#, % individual acquisitions)	282	76.4%	357	83.8%	229	80.4%	133	88.1%	21	100.0%	4	80.0%	1026	81.6%
Reacquisitions^b (#, % individual acquisitions)	87	23.6%	69	16.2%	56	19.6%	18	11.9%	0	0.0%	1	20.0%	231	18.4%
Household introductions ^a ^, ^c (#,per-swab probability)	175	0.143	249	0.215	173	0.198	70	0.036	9	0.028	3	0.059	679	0.123
Unique HH introduction (#, % of HH introductions)	102	58.3%	165	66.3%	125	72.3%	36	51.4%	5	55.6%	1	33.3%	434	63.9%
Concurrent HH introduction (#, % of HH introductions)	73	41.7%	84	33.7%	48	27.7%	34	48.6%	4	44.4%	2	66.7%	245	36.1%

^a Including 73 swabs for which two serotypes were identified.

^b New acquisitions defined as acquisition of serotype not previously carried; reacquisition defined as acquisition of a previously-carried serotype.

^c Household introductions classified as “unique” if the participant was the only one in the family to acquire the new serotype; “concurrent” if more than one individual acquired the serotype simultaneously.