Estimates of the Prevalence of Pandemic (H1N1) 2009, United States, April?July 2009

[Farmer]

Estimate of US H1N1 cases, hospitalizations and deaths.

Reed C, Angulo FJ, Swerdlow DL, Lipsitch M, Meltzer MI, Jernigan D, et al. Estimates of the prevalence of pandemic (H1N1) 2009, United States, April?July 2009. Emerg Infect Dis [serial on the Internet]. 2009 Dec; [Epub ahead of print]

Summary:
Through July 2009, a total of 43,677 laboratory-confirmed cases of influenza A pandemic (H1N1) 2009 were reported in the United States, which is likely a substantial underestimate of the true number. Correcting for under-ascertainment using a multiplier model, we estimate that 1.8 million?5.7 million cases occurred, including 9,000?21,000 hospitalizations.

/snip from conclusions:
We estimate that the total number of pandemic (H1N1) 2009 cases in the United States during April?July 2009 may have been up to 140? greater than the reported number of laboratory confirmed cases./

Hat tip to Mike Coston


See complete report here: http://www.cdc.gov/eid/content/15/12/pdfs/09-1413.pdf

 

[cartski]

Re: Estimates of the Prevalence of Pandemic (H1N1) 2009, United States, April?July 2009

Estimate of US H1N1 cases, hospitalizations and deaths.

Reed C, Angulo FJ, Swerdlow DL, Lipsitch M, Meltzer MI, Jernigan D, et al. Estimates of the prevalence of pandemic (H1N1) 2009, United States, April?July 2009. Emerg Infect Dis [serial on the Internet]. 2009 Dec; [Epub ahead of print]

Summary:
Through July 2009, a total of 43,677 laboratory-confirmed cases of influenza A pandemic (H1N1) 2009 were reported in the United States, which is likely a substantial underestimate of the true number. Correcting for under-ascertainment using a multiplier model, we estimate that 1.8 million?5.7 million cases occurred, including 9,000?21,000 hospitalizations.

/snip from conclusions:
We estimate that the total number of pandemic (H1N1) 2009 cases in the United States during April?July 2009 may have been up to 140? greater than the reported number of laboratory confirmed cases./

Hat tip to Mike Coston


See complete report here: http://www.cdc.gov/eid/content/15/12/pdfs/09-1413.pdf

From the paper's methods:

"Using this approach, between April and July 2009, we estimate that the median multiplier of reported to estimated cases was 79; that is, every reported case of pandemic (H1N1) 2009 may represent 79 total cases, with a 90% probability range of 47?148, for a median estimate of 3.0 million (range 1.8?5.7 million) symptomatic cases of pandemic (H1N1) 2009 in the United States.

Likewise, we estimate that every hospitalized case of pandemic (H1N1) 2009 that was reported may represent a median of 2.7 total hospitalized persons (90% range 1.9?4.3). This represents a median estimate of 14,000 (range 9,000?21,000) hospitalizations (Table 2) and thus an estimated ratio of hospitalizations to total symptomatic cases of 0.45% (range 0.16%?1.2%)."

I wonder how these estimates compare to the actuals for that time period.

I wonder how the current numbers compare to the estimates with a multiplier of 79.

J.