1125. Preliminary Estimates of Global 2009 H1N1 Influenza Mortality
Session: Poster Abstract Session: Influenza and H1N1 Diagnosis, Epidemiology, and Viral Outcome
Saturday, October 22, 2011
Room: Poster Hall B1
Background: During April 2009-August 2010, 18,500 laboratory-confirmed 2009 H1N1 influenza deaths were reported globally representing a fraction of actual 2009 H1N1 mortality  We estimated global 2009 H1N1 respiratory mortality and years of life lost (YLL) in the first year of virus circulation in each country.

Methods: We used ranges of 2009 H1N1 cumulative one year symptomatic attack rates (sAR) from 11 countries (0-17 yrs: 4-33%; 18-64 yrs:  1-12%; >65 yrs: 1-4%), and 2009 H1N1 symptomatic case fatality ratios (sCFR) from three higher resource countries (0-17 yrs: 0.004-0.008%; 18-64 yrs: 0.027-0.051%; >65 yrs: 0.090-0.316%). We adjusted the sCFR for risk of influenza death across countries with a mortality multiplier (MM).  The MM was calculated as the ratio of the median and interquartile range (IQR) of lower respiratory tract mortality rates (LRTMR) in each WHO Region-Mortality Stratum* to the median LRTMR in very low mortality countries (high mortality countries in the Americas, Mediterranean, and Southeast Asia:  2, IQR 1-3; high/highest mortality countries in Africa:  5, IQR 2-7; other countries: no MM). Using Monte Carlo resampling, we multiplied values chosen from the sAR, sCFR, and MM ranges to estimate mortality rates and applied the rates to country population estimates by age group from each of the 192 United Nations member states to calculate 2009 H1N1 deaths. We estimated YLL using life expectancy by country and age group.

Results:  We estimate that 249,000 (90% CI 48,000-716,000) 2009 H1N1 deaths occurred globally of which 144,000 (90% CI 18,000-415,000) (58%) occurred in Africa and Southeast Asia, and 216,000 (90% CI 34,000-563,000) (87%) occurred in persons <65 years.  An estimated 9,911,000 (90% CI 3,933,000-18,820,000) years of life were lost. 

Conclusion: Estimated 2009 H1N1 respiratory mortality was at least two-fold higher than reported laboratory-confirmed deaths, and lower resource countries were disproportionately affected.  Although estimated mortality may have been lower than that of some prior pandemics, the majority of 2009 H1N1 deaths were in persons <65 years resulting in a substantial number of years of life lost.


Subject Category: N. Hospital-acquired and surgical infections, infection control, and health outcomes including general public health and health services research

Fatimah S. Dawood, MD1, A. Danielle Iuliano, PhD, MPH2, Carrie Reed, ScD2, Martin I. Meltzer, PhD, MS2, Shobha Broor, MD3, W. Abdullah Brooks, MD, MPH4, Aubree Gordon, PhD, MPH5, Nguyen Tran Hien, MD, PhD6, Peter Horby, MBBS7, Mark Katz, MD8, Joel Montgomery, PhD9, Kåre Mølbak, MD10, Richard Pebody, MBBS11, Anne M. Presanis, MBBS11, Anneke Steens, PhD12, Jacco Wallinga, PhD, MSc12, Hongjie Yu, MD13, David K. Shay, MD, MPH2, Joseph Bresee, MD14 and Marc-Alain Widdowson, VetMB, MScb2, (1) , Centers for Disease Control and Prevention, Atlanta, GA, (2)Centers for Disease Control and Prevention, Atlanta, GA, (3)All India Institute of Medical Sciences, New Delhi, India, (4)International Centre for Diarrhoeal Disease Research, Dhaka, Bangladesh, (5)University of California, Berkeley, CA, (6)National Institute for Hygiene and Epidemiology, Hanoi, Vietnam, (7)Oxford University Clinical Research Unit, Hanoi, Vietnam, (8)Centers for Disease Control and Prevention, Nairobi, Kenya, (9)Centers for Disease Control and Prevention, Lima, Peru, (10)Statens Serum Institute, Copenhagen, Denmark, (11)Medical Research Council, Biostatistics Unit, Cambridge, United Kingdom, (12)Centre for Infectious Disease Control, National Institute for Public Health and the Environment, Bilthoven, Netherlands, (13)Chinese Centers for Disease Control and Prevention, Beijing, China, (14)Centers for Diseases Control and Prevention, Atlanta, GA


F. S. Dawood, None

A. D. Iuliano, None

C. Reed, None

M. I. Meltzer, None

S. Broor, None

W. A. Brooks, None

A. Gordon, None

N. T. Hien, None

P. Horby, None

M. Katz, None

J. Montgomery, None

K. Mølbak, None

R. Pebody, None

A. M. Presanis, None

A. Steens, None

J. Wallinga, None

H. Yu, None

D. K. Shay, None

J. Bresee, None

M. A. Widdowson, None

Findings in the abstracts are embargoed until 12:01 a.m. EST Thursday, Oct. 20 with the exception of research findings presented at IDSA press conferences.