Death Patterns during the 1918 Influenza Pandemic in Chile - Volume 20, Number 11—November 2014 - Emerging Infectious Disease journal - CDC
Volume 20, Number 11—November 2014
Death Patterns during the 1918 Influenza Pandemic in Chile
The 1918 influenza A(H1N1) pandemic was one of the most devastating epidemic events in recent history; an estimated ≈1% of the global population (20–50 million persons) died (1), including >14 million in India alone (2). Our understanding of the epidemiologic patterns of this pandemic has improved over the past decade as a result of intensive efforts to locate, digitize, and analyze archival disease records (3). In particular, studies focusing on the United States (4,5), Mexico (6), Colombia (7), Brazil (8), and Peru (9) have shed light on geographic variation in the patterns of timing, intensity, and patient age during successive pandemic waves across the Americas. Yet there have been no reports from temperate locales of South America; this gap prevents a complete understanding of the epidemiology of the pandemic throughout the continent and across different climatic zones.
A consistent finding across reports from North America, Europe, Latin America, and Asia (4–7,9–12) is the disproportionate increase in mortality rates among young adults during the pandemic period compared with prepandemic years. Further reports from the United States and Europe have shown that influenza-related deaths among seniors (>50 years of age) were significantly reduced during the lethal 1918–19 pandemic wave relative to baseline periods. In contrast, this protective effect for seniors did not apply to Mexico, Colombia, and remote island populations, probably because of differences in prior immunity between regions (6,13). In addition, large geographic variations in mortality rates from the pandemic have been documented (14–16).
Although recent studies have highlighted latitudinal and climatic variations in contemporary influenza epidemics and pandemics (17–20), little is known about the role of climate in the severity or timing of the 1918 pandemic. Chile is a unique country; it spans an extensive latitudinal gradient, has a variety of climatic zones, and has preserved historical records dating back to the 1918 pandemic period. We characterized geographic variation in pandemic influenza–related death patterns in Chile by using national and regional death statistics combined with a unique dataset of individual-level death certificates from Concepción, a large city in southern Chile. We discuss our findings in relation to those reported elsewhere in the Americas and globally.
Dr Chowell is an associate professor in the School of Human Evolution and Social Change at Arizona State University and Research Fellow at the Fogarty International Center, National Institutes of Health. His research interests include mathematical modeling of infectious disease transmission with a focus on influenza and the role of public health interventions. He is also interested in the quantitative characterization of the 1918 influenza pandemic in the Americas.
This research was conducted in the context of the Multinational Influenza Seasonal Mortality Study, an ongoing international collaborative effort to understand influenza epidemiological and evolutionary patterns, led by the Fogarty International Center, National Institutes of Health (http://www.origem.info/misms/index.php). Funding for this project comes in part (L.S.) from the RAPIDD (Research and Policy for Infectious Disease Dynamics) program of the Science & Technology Directorate, Department of Homeland Security, and from the Office of Global Affairs, International Influenza Unit, in the Office of the Secretary of the US Department of Health and Human Services.
- Johnson NP, Mueller J. Updating the accounts: global mortality of the 1918–1920 “Spanish” influenza pandemic. Bull Hist Med. 2002;76:105–15.
- Chandra S, Kuljanin G, Wray J. Mortality from the influenza pandemic of 1918–1919: the case of India. Demography. 2012;49:857–65.
- Simonsen L, Viboud C, Chowell G, Andreasen V, Olson DR, Parekh V, The need for interdisciplinary studies of historic pandemics. Vaccine.2011;29(Suppl 2):B1–5.
- Olson DR, Simonsen L, Edelson PJ, Morse SS. Epidemiological evidence of an early wave of the 1918 influenza pandemic in New York City. Proc Natl Acad Sci U S A. 2005;102:11059–63.
- Viboud C, Eisenstein J, Reid AH, Janczewski TA, Morens DM, Taubenberger JK. Age- and sex-specific mortality associated with the 1918–1919 influenza pandemic in Kentucky. J Infect Dis. 2013;207:721–9.
- Chowell G, Viboud C, Simonsen L, Miller MA, Acuna-Soto R. Mortality patterns associated with the 1918 influenza pandemic in Mexico: evidence for a spring herald wave and lack of preexisting immunity in older populations. J Infect Dis. 2010;202:567–75.
- Chowell G, Viboud C, Simonsen L, Miller MA, Acuna-Soto R, Diaz JM, The 1918–19 influenza pandemic in Boyacá, Colombia. Emerg Infect Dis.2012;18:48–56.
- Alonso WJ, Nascimento FC, Acuna-Soto R, Schuck-Paim C, Miller MA. The 1918 influenza pandemic in Florianopolis: a subtropical city in Brazil.Vaccine. 2011;29(Suppl 2):B16–20.
- Chowell G, Viboud C, Simonsen L, Miller MA, Hurtado J, Soto G, The 1918–1920 influenza pandemic in Peru. Vaccine. 2011;29(Suppl 2):B21–6.
- Erkoreka A. The Spanish influenza pandemic in occidental Europe (1918–1920) and victim age. Influenza Other Respir Viruses. 2010;4:81–9.
- Lee VJ, Chen MI, Chan SP, Wong CS, Cutter J, Goh KT, Influenza pandemics in Singapore, a tropical, globally connected city. Emerg Infect Dis.2007;13:1052–7.
- Hsieh YH. Excess deaths and immunoprotection during 1918–1920 influenza pandemic, Taiwan. Emerg Infect Dis. 2009;15:1617–9.
- Mamelund SE. Geography may explain adult mortality from the 1918–20 influenza pandemic. Epidemics. 2011;3:46–60.
- Chowell G, Bettencourt LM, Johnson N, Alonso WJ, Viboud C. The 1918–1919 influenza pandemic in England and Wales: spatial patterns in transmissibility and mortality impact. Proc Biol Sci. 2008;275:501–9.
- Murray CJ, Lopez AD, Chin B, Feehan D, Hill KH. Estimation of potential global pandemic influenza mortality on the basis of vital registry data from the 1918–20 pandemic: a quantitative analysis. Lancet. 2006;368:2211–8.
- Acuna-Soto R, Viboud C, Chowell G. Influenza and pneumonia mortality in 66 large cities in the United States in years surrounding the 1918 pandemic. PLoS ONE. 2011;6:e23467.
- Alonso WJ, Viboud C, Simonsen L, Hirano EW, Daufenbach LZ, Miller MA. Seasonality of influenza in Brazil: a traveling wave from the Amazon to the subtropics. Am J Epidemiol. 2007;165:1434–42.
- Tamerius J, Nelson MI, Zhou SZ, Viboud C, Miller MA, Alonso WJ. Global influenza seasonality: reconciling patterns across temperate and tropical regions. Environ Health Perspect. 2010;119:439–45.
- Viboud C, Alonso WJ, Simonsen L. Influenza in tropical regions. PLoS Med. 2006;3:e89.
- Tamerius JD, Shaman J, Alonso WJ, Bloom-Feshbach K, Uejio CK, Comrie A, Environmental predictors of seasonal influenza epidemics across temperate and tropical climates. PLoS Pathog. 2013;9:e1003194.
- Anuarios Estadísticas de la Republica de Chile (1915–1920) Oficina Central de Estadistica, Soc. Imp. Lit. Universo, Vols. 1–2. Santiago de Chile, 1915–1921.
- Instituto Nacional de Estadísticas. Chile: nacimientos, defunciones, poblacion y tasas brutas de natalidad, de mortalidad, y de crecimiento natural, 1848–2007. Santiago, Chile.
- Schuck-Paim C, Viboud C, Simonsen L, Miller MA, Moura FE, Fernandes RM, Were equatorial regions less affected by the 2009 influenza pandemic? The Brazilian experience. PLoS ONE. 2012;7:e41918.
- Serfling RE. Methods for current statistical analysis of excess pneumonia-influenza deaths. Public Health Rep. 1963;78:494–506.
- Viboud C, Grais RF, Lafont BA, Miller MA, Simonsen L. Multinational impact of the 1968 Hong Kong influenza pandemic: evidence for a smoldering pandemic. J Infect Dis. 2005;192:233–48.
- Andreasen V, Viboud C, Simonsen L. Epidemiologic characterization of the 1918 influenza pandemic summer wave in Copenhagen: implications for pandemic control strategies. J Infect Dis. 2008;197:270–8.
- Serfling RE, Sherman IL, Houseworth WJ. Excess pneumonia-influenza mortality by age and sex in three major influenza A2 epidemics, United States, 1957–58, 1960 and 1963. Am J Epidemiol. 1967;86:433–41 .
- Chowell G, Towers S, Viboud C, Fuentes R, Sotomayor V, Simonsen L, The influence of climatic conditions on the transmission dynamics of the 2009 A/H1N1 influenza pandemic in Chile. BMC Infect Dis. 2012;12:298.
- Edgington ES, Onghena P. Randomization tests. Boca Raton (FL): Chapman & Hall/CRC; 2007.
- Ansart S, Pelat C, Boelle PY, Carrat F, Flahault A, Valleron AJ. Mortality burden of the 1918–1919 influenza pandemic in Europe. Influenza Other Respir Viruses. 2009;3:99–106.
- Richard SA, Sugaya N, Simonsen L, Miller MA, Viboud C. A comparative study of the 1918–1920 influenza pandemic in Japan, USA and UK: mortality impact and implications for pandemic planning. Epidemiol Infect. 2009;137:1062–72.
- Andreasen V, Simonsen L. The perils of using annual all-cause mortality data to estimate pandemic influenza burden. Vaccine. 2011;29(Suppl 2):B49–55.
- Carbonetti A. La pandemia de gripe española en la argentina, 1918–1919. Desacatos. 2010;32:159–74.
- Anales del Departamento Nacional de Higiene de Argentina. Vol. 26, 1921.
- Direccion General de Estadistica. Anuario Estadistico de la Republica Oriental de Uruguay, 1915–1920.
- Ammon CE. Spanish flu epidemic in 1918 in Geneva, Switzerland. Euro Surveill. 2002;7:190–2 .
- Sheng ZM, Chertow DS, Ambroggio X, McCall S, Przygodzki RM, Cunningham RE, Autopsy series of 68 cases dying before and during the 1918 influenza pandemic peak. Proc Natl Acad Sci U S A. 2011;108:16416–21.
- Valleron AJ, Cori A, Valtat S, Meurisse S, Carrat F, Boelle PY. Transmissibility and geographic spread of the 1889 influenza pandemic. Proc Natl Acad Sci U S A. 2010;107:8778–81.
- Lowen AC, Mubareka S, Steel J, Palese P. Influenza virus transmission is dependent on relative humidity and temperature. PLoS Pathog.2007;3:1470–6 .
- Shaman J, Pitzer VE, Viboud C, Grenfell BT, Lipsitch M. Absolute humidity and the seasonal onset of influenza in the continental United States. PLoS Biol. 2010;8:e1000316.
Suggested citation for this article: Chowell G, Simonsen L, Flores J, Miller MA, Viboud C. Death patterns during the 1918 influenza pandemic in Chile. Emerg Infect Dis [Internet]. 2014 Nov [date cited]. http://dx.doi.org/10.3201/eid2011.130632