Table 1. Demographic characteristics.

Characteristic		Group I				Group II
		0118S	0218S	0318S	Control	0118S	0218S	0318S	Control
Total		67	67	67	67	67	67	67	67
Sex
	Female	41	38	43	52	38	47	38	45
	Male	26	29	24	15	29	20	29	22
Mean age: adult (yr)/child (yr)/infant (mo)		14.34	14.04	14.12	14.15	26.88	26.28	26.13	27.13