Volume 15, Number 6—June 2009
Research
Case-based Surveillance of Influenza Hospitalizations during 2004–2008, Colorado, USA
, Dennis Lezotte, and Ann-Christine Nyquist
Table 1
Characteristics of patients hospitalized with influenza, Colorado, USA, 2004–08 influenza seasons*
| Characteristics | Influenza season (October 1–May 31), no. (%) patients |
|||
|---|---|---|---|---|
| 2004–05 | 2005–06 | 2006–07 | 2007–08 | |
| Total recorded cases |
978 |
848 |
367 |
1,004 |
| Influenza type | ||||
| A | 777 (79.45) | 699 (82.43) | 345 (94.01) | 629 (62.65) |
| B | 127 (12.99) | 110 (12.97) | 12 (3.27) | 343 (34.16) |
| Unknown |
74 (7.57) |
39 (4.60) |
10 (2.72) |
32 (3.19) |
| Age | ||||
| <6 mo | 64 (6.54) | 81 (9.55) | 39 (10.63) | 79 (7.87) |
| 6–23 mo | 72 (7.36) | 103 (12.15) | 46 (12.53) | 78 (7.77) |
| 2–4 y | 56 (5.73) | 59 (6.96) | 27 (7.36) | 65 (6.47) |
| 5–17 y | 56 (5.73) | 72 (8.49) | 29 (7.90) | 74 (7.37) |
| 18–49 y | 140 (14.31) | 86 (10.14) | 78 (21.25) | 180 (17.93) |
| 50–64 y | 149 (15.24) | 103 (12.15) | 39 (10.63) | 142 (14.14) |
| 65–79 y | 201 (20.55) | 169 (19.93) | 56 (15.26) | 179 (17.83) |
| >80 y |
240 (24.54) |
175 (20.64) |
53 (14.44) |
207 (20.62) |
| Gender | ||||
| M | 488 (49.90) | 405 (47.76) | 186 (50.68) | 461 (45.92) |
| F | 485 (49.59) | 443 (52.24) | 180 (49.05) | 517 (51.49) |
| Unknown |
5 (0.51) |
0 (0.00) |
1 (0.27) |
26 (2.59) |
| Region* | ||||
| Western Slope | 57 (5.83) | 100 (11.79) | 31 (8.45) | 94 (9.36) |
| Northern Front Range | 122 (12.47) | 108 (12.74) | 48 (13.08) | 121 (12.05) |
| Denver Metro | 550 (56.24) | 383 (45.17) | 210 (57.22) | 520 (51.79) |
| South Central | 36 (3.68) | 32 (3.77) | 8 (2.18) | 14 (1.39) |
| San Luis Valley | 7 (0.72) | 8 (0.94) | 12 (3.27) | 15 (1.49) |
| Southern Front Range | 174 (17.79) | 177 (20.87) | 48 (13.08) | 205 (20.42) |
| Eastern Plains | 32 (3.27) | 40 (4.72) | 10 (2.72) | 35 (3.49) |
*Colorado regions can be further divided into counties: Western Slope: Archuleta, Delta, Dolores, Eagle, Garfield, Grand, Gunnison, Hinsdale, Jackson, La Plata, Mesa, Moffat, Montezuma, Montrose, Ouray, Pitkin, Rio Blanco, Routt, San Juan, San Miguel, Summit; Northern Front Range: Larimer, Weld; Denver Metro: Adams, Arapahoe, Boulder, Broomfield, Denver, Douglas, Jefferson; South Central: Chaffee, Clear Creek, Custer, Fremont, Gilpin, Huerfano, Lake, Las Animas, Park, Teller; San Luis Valley: Alamosa, Conejos, Costilla, Mineral, Rio Grande, Saguache; Southern Front Range: El Paso, Pueblo, and Eastern Plains: Baca, Bent, Cheyenne, Crowley, Elbert, Kiowa, Kit Carson, Lincoln, Logan, Morgan, Otero, Phillips, Prowers, Sedgwick, Washington, Yuma.