Table 2. Prevalence of tuberculosis infection and risk difference in tuberculosis infection between 1918 household contacts and 1179 community members according to age and BCG vaccination status in Kampala, Uganda, 1995–2004.

Characteristic	Category	Exposure	N	Number Infected	Infected (%)	Risk Difference	95% CI
Total		Contacts	1918	1369	71.4	47.4	44.3, 50.6
		Controls	1179	282	23.9
Age	0–5	Contacts	508	320	63.0	50.3	44.5, 56.2
		Controls	253	32	12.6
	6–15	Contacts	691	475	68.7	53.9	48.7, 59.2
		Controls	311	46	14.8
	16–25	Contacts	364	285	78.3	46.7	39.8, 53.6
		Controls	275	87	31.6
	26–45	Contacts	283	226	79.9	45.5	38.1, 52.9
		Controls	262	90	34.4
	≥46	Contacts	72	63	87.5	52.9	39.9, 65.8
		Controls	78	27	34.6
BCG Vaccine	Yes	Contacts	1349	935	69.3	47.4	43.6, 51.2
		Controls	793	174	21.9
	No	Contacts	499	388	77.7	49.7	44.0, 55.5
		Controls	382	107	28.0

^‡Vaccination status missing or uncertain in 70 household contacts and 4 community members.

*Defined as the sum of contacts with TS>10 mm within 3 months of household evaluation who do not have evidence of active tuberculosis.