Geography May Explain Adult Mortality from the 1918-20 Influenza Pandemic
Geography May Explain Adult Mortality from the 1918-20 Influenza Pandemic
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DOI：
10.1016/j.epidem.2011.02.001
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发表时间：
2011-03-01
期刊：
影响因子：
3.8
通讯作者：
Mamelund, Svenn-Erik
中科院分区：
文献类型：
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作者：
Mamelund, Svenn-Erik
季节性流感对儿童和老年人造成的影响最为明显，导致按年龄划分的粗死亡率呈 U 形。相比之下，1918-20 年 A(H1N1) 大流行死亡率呈 W 形。在调整季节性基线时，年轻人的死亡率高于预期，但老年人的死亡率低于预期。老年人死亡率低于预期，是 1918-20 年间城市社会总死亡率相对较低的原因之一（30 岁受到保护，因为他们在 1889 年之前接触过 H1 类病毒）。这一假设假设人们生活在城市疾病库的范围内。这里，我分析了原住民 30 岁以后的死亡率，这些原住民因地理隔离而被认为很少接触流感。结果显示，北极和太平洋地区的居民的死亡率也出现了下降。 30 岁以后的相对死亡率。然而，居住在偏远地区的老年人的死亡率并不低于预期，这表明他们在偏远地区的人口中，粗略总死亡率和所有 30 岁以上成年人的死亡率仍然极高，教区记录定量证实了一些轶事，即 5-14 岁的儿童是一些北极社区中唯一的幸存者。 90%）。高并发疾病负荷、拥挤、低遗传变异性、缺乏基本护理以及很少接触其他形式的 1890-1917 流感病毒也可能发挥了作用。这种形式的免疫交叉保护只能解释为针对内部蛋白质的细胞免疫，这些内部蛋白质显示出比表面蛋白质更少的株间变异 (C) 2011 Elsevier。 B.V.保留所有权利。
Seasonal influenza takes its most pronounced toll on children and the elderly, giving the crude age-specific mortality rates a U-shape. In contrast, A(H1N1) 1918-20 pandemic mortality was W-shaped. When adjusting for the seasonal baseline, young adults had higher but the elderly lower than expected mortality. The lower than expected mortality for the elderly is one reason why total mortality in urban societies were relatively low in 1918-20 (30 years was protected because they were exposed to H1-like viruses prior to 1889. This hypothesis assumes that people lived within the reach of the urban disease pools.Here I analyze mortality after age 30 in aboriginal populations assumed to be infrequently exposed to influenza due to their geographic isolation. Results show that Arctic and Pacific peoples also experienced a decline in relative mortality after age 30. However, the remotely living elderly did not have lower than expected mortality, suggesting that they had less prior exposure to influenza than their urban counterpart. Crude total mortality and mortality for all adults >30 years was nevertheless extremely high in the remote populations. Parish records quantitatively confirmed the anecdotes that children 5-14 years were the only survivors in some Arctic communities.Low exposure to H1-like viruses in adults could not alone explain the high total mortality in remote populations (up to 90%). A high concurrent disease load, crowding, low genetic variability, a lack of basic care, and infrequent exposure to other forms of influenza virus 1890-1917 may have played a role as well. This form of immunological cross-protection from previous exposure to A-type influenza viruses other than H1N1 can only be explained as a consequence of cellular immunity against internal proteins that show less inter-strain variation than the surface proteins. (C) 2011 Elsevier B.V. All rights reserved.