INFLUENZA VIRUSES ISOLATED BY
WHO/NREVSS Collaborating Laboratories
2003 - 2004 Season

Year/Week	Number of Labs Reporting	Total Specimens Tested	A(H1N1) & A(H1N2)	A(H3N2)	A(Unk)	B	Total # Tested	% Positive
40	109	1430	0	2	19	1	22	1.54
41	120	1682	0	3	74	0	77	4.58
42	118	2176	0	17	235	1	253	11.63
43	124	2568	0	56	398	4	458	17.83
44	125	2753	0	100	435	0	535	19.43
45	134	3553	1	273	585	3	862	24.26
46	136	4595	0	381	908	2	1291	28.1
47	146	5942	0	585	1375	8	1968	33.12
48	147	6479	0	489	1752	10	2251	34.74
49	156	9598	0	977	2260	32	3269	34.06
50	154	12422	0	1401	2660	29	4090	32.93
51	149	11783	0	1084	2525	20	3629	30.8
52	147	9748	0	569	1826	16	2411	24.73
53	138	8461	0	463	1226	12	1701	20.1
01	138	6936	0	280	573	9	862	12.43
02	137	5411	0	169	331	5	505	9.33
03	126	4329	0	96	161	3	260	6.01
04	125	4166	0	93	70	3	166	3.98
05	121	3661	1	46	58	2	107	2.92
06	116	3530	0	24	36	5	65	1.84
07	117	3136	0	29	19	8	56	1.79
08	112	2559	0	16	10	12	38	1.48
09	111	2651	0	4	6	8	18	0.68
10	109	2369	0	2	6	6	14	0.59
11	109	2239	0	4	7	2	13	0.58
12	110	1801	0	5	4	15	24	1.33
13	105	1850	0	3	5	9	17	0.92
14	102	1778	0	0	1	8	9	0.51
15	96	1564	0	0	3	12	15	0.96
16	103	1449	0	2	11	11	24	1.66
17	93	1377	0	0	4	7	11	0.8
18	97	1298	0	0	3	6	9	0.69
19	89	1241	0	0	0	2	2	0.16
20	80	1105	0	0	1	3	4	0.36
21	81	1055	0	1	2	3	6	0.57
22	79	823	0	0	2	4	6	0.73
23	73	793	0	0	1	2	3	0.38
24	77	844	0	0	0	2	2	0.24
25	82	741	0	1	1	1	3	0.4
26	72	730	0	1	0	2	3	0.41
27	70	573	0	0	0	1	1	0.17
28	68	746	0	0	0	2	2	0.27
29	67	563	0	0	0	2	2	0.36
30	73	671	0	0	0	0	0	0
31	76	628	0	1	0	1	2	0.32
32	74	620	0	1	0	0	1	0.16
33	73	647	0	0	0	1	1	0.15
34	75	823	0	0	3	1	4	0.49
35	77	827	0	4	0	0	4	0.48
36	78	822	0	0	0	3	3	0.36
37	77	907	0	1	4	2	7	0.77
38	77	890	0	2	1	1	4	0.45
39	80	919	0	4	8	2	14	1.52
Totals	5528	152262	2	7189	17609	304	25104	16.49