Volume 15, Number 12—December 2009
Dispatch
Estimates of the Prevalence of Pandemic (H1N1) 2009, United States, April–July 2009
Carrie Reed
, Frederick J. Angulo, David L. Swerdlow, Marc Lipsitch, Martin I. Meltzer, Daniel Jernigan, and Lyn Finelli
, Frederick J. Angulo, David L. Swerdlow, Marc Lipsitch, Martin I. Meltzer, Daniel Jernigan, and Lyn FinelliTable 2
Estimates of pandemic (H1N1) 2009–related cases and rates of illness and hospitalization by age distribution of confirmed case-patients, United States, April–July 2009
| Parameter | Estimated no. case-patients |
Estimated rate/100,000* |
|||
|---|---|---|---|---|---|
| Median | 90% range | Median | 90% range | ||
| Total no. case-patients by age group, y† | 3,052,768 | 1,831,115–5,720,928 | 997 | 598–1,868 | |
| 0–4 | 397,033 | 238,149–744,045 | 1,870 | 1,122–3,505 | |
| 5–24 | 1,820,284 | 1,091,845–3,411,237 | 2,196 | 1,317–4,115 | |
| 25–49 | 612,862 | 367,608–1,148,511 | 577 | 346–1,081 | |
| 50–64 | 180,297 | 108,146–337,879 | 319 | 192–599 | |
| >65 |
42,292 |
25,368–79,256 |
107 |
64–201 |
|
| No. hospitalized case-patients by age group, y | 13,764 | 9,278–21,305 | 4.5 | 3.0–7.0 | |
| 0–4 | 2,768 | 1,866–4,285 | 13.0 | 8.8–20.2 | |
| 5–24 | 4,991 | 3,364–7,725 | 6.0 | 4.1–9.3 | |
| 25–49 | 3,440 | 2,319–5,324 | 3.2 | 2.2–5.0 | |
| 50–64 | 1,912 | 1,289–2,959 | 3.4 | 2.3–5.2 | |
| >65 |
654 |
441–1,012 |
1.7 |
1.1–2.6 |
|
| Multiplier | |||||
| Hospitalized | 2.7 | 1.7–4.5 | – | – | |
| Nonhospitalized | 79 | 47–148 | – | – | |
| Through May 12 | 33 | 23–49 | – | – | |
| After May 12 | 84 | 50–163 | – | – | |
*United States Population Estimates, 2009.
†Age distributions from line list and aggregate reports of laboratory-confirmed cases and hospitalizations to the Centers for Disease Control and Prevention through July 23, 2009.
