Chowell Gerardo, Simonsen Lone, Fuentes Rodrigo, Flores Jose, Miller Mark A, Viboud Cécile
Georgia State University, Atlanta, Georgia, USA.
Fogarty International Center, National Institutes of Health, Bethesda, MD, USA.
Influenza Other Respir Viruses. 2017 May;11(3):230-239. doi: 10.1111/irv.12439. Epub 2017 Mar 31.
Epidemiological studies of the 1957 influenza pandemic are scarce, particularly from lower-income settings.
We analyzed the spatial-temporal mortality patterns of the 1957 influenza pandemic in Chile, including detailed age-specific mortality data from a large city, and investigated risk factors for severe mortality impact across regions.
Chile exhibited two waves of excess mortality in winter 1957 and 1959 with a cumulative excess mortality rate of 12 per 10 000, and a ~10-fold mortality difference across provinces. High excess mortality rates were associated with high baseline mortality (R =41.8%; P=.02), but not with latitude (P>.7). Excess mortality rates increased sharply with age. Transmissibility declined from R=1.4-2.1 to R=1.2-1.4 between the two pandemic waves.
The estimated A/H2N2 mortality burden in Chile is the highest on record for this pandemic-about three to five times as severe as that experienced in wealthier nations. The global impact of this pandemic may be substantially underestimated from previous studies based on high-income countries.
关于1957年流感大流行的流行病学研究稀缺，尤其是来自低收入地区的研究。
我们分析了智利1957年流感大流行的时空死亡模式，包括来自一个大城市的详细年龄特异性死亡数据，并调查了各地区严重死亡影响的风险因素。
智利在1957年和1959年冬季出现了两波超额死亡，累计超额死亡率为每10000人中有12人，各省之间的死亡率相差约10倍。高超额死亡率与高基线死亡率相关（R = 41.8%；P = 0.02），但与纬度无关（P > 0.7）。超额死亡率随年龄急剧上升。在两波大流行之间，传播率从R = 1.4 - 2.1降至R = 1.2 - 1.4。
智利估计的A/H2N2死亡负担是此次大流行有记录以来最高的——约为富裕国家所经历负担的三到五倍。基于高收入国家的以往研究可能大幅低估了此次大流行的全球影响。
