Table 1.

Frequency of different influenza strains in analyzed Swiss samples

Season	A H1N1		A H1N2		A H3N2		B		Total
	Cases	proportion	cases	proportion	cases	proportion	cases	proportion
1995/96	146	51%		0%	109	38%	30	11%	285
1996/97	2	1%		0%	234	68%	109	32%	345
1997/98	5	2%		0%	321	98%		0%	326
1998/99		0%		0%	83	37%	143	63%	226
1999/00		0%		0%	115	100%		0%	115
2000/01	110	89%		0%	1	1%	13	10%	124
2001/02		0%	1	0%	103	44%	130	56%	234
2002/03	1	1%	5	3%	125	68%	52	28%	183
2003/04	1	0%		0%	225	99%	2	1%	228
2004/05	35	12%		0%	225	75%	41	14%	301
2005/06	9	4%		0%	13	6%	183	89%	205

The data has kindly been provided by the Swiss Federal Office of Public Health.