摘要

BACKGROUND:Accurate measures of the severity of pandemic (H1N1) 2009 influenza (pH1N1) are needed to assess the likely impact of an anticipated resurgence in the autumn in the Northern Hemisphere. Severity has been difficult to measure because jurisdictions with large numbers of deaths and other severe outcomes have had too many cases to assess the total number with confidence. Also, detection of severe cases may be more likely, resulting in overestimation of the severity of an average case. We sought to estimate the probabilities that symptomatic infection would lead to hospitalization, ICU admission, and death by combining data from multiple sources. METHODS AND FINDINGS:We used complementary data from two US cities: Milwaukee attempted to identify cases of medically attended infection whether or not they required hospitalization, while New York City focused on the identification of hospitalizations, intensive care admission or mechanical ventilation (hereafter, ICU), and deaths. New York data were used to estimate numerators for ICU and death, and two sources of data--medically attended cases in Milwaukee or self-reported influenza-like illness (ILI) in New York--were used to estimate ratios of symptomatic cases to hospitalizations. Combining these data with estimates of the fraction detected for each level of severity, we estimated the proportion of symptomatic patients who died (symptomatic case-fatality ratio, sCFR), required ICU (sCIR), and required hospitalization (sCHR), overall and by age category. Evidence, prior information, and associated uncertainty were analyzed in a Bayesian evidence synthesis framework. Using medically attended cases and estimates of the proportion of symptomatic cases medically attended, we estimated an sCFR of 0.048% (95% credible interval [CI] 0.026%-0.096%), sCIR of 0.239% (0.134%-0.458%), and sCHR of 1.44% (0.83%-2.64%). Using self-reported ILI, we obtained estimates approximately 7-9 x lower. sCFR and sCIR appear to be highest in persons aged 18 y and older, and lowest in children aged 5-17 y. sCHR appears to be lowest in persons aged 5-17; our data were too sparse to allow us to determine the group in which it was the highest. CONCLUSIONS:These estimates suggest that an autumn-winter pandemic wave of pH1N1 with comparable severity per case could lead to a number of deaths in the range from considerably below that associated with seasonal influenza to slightly higher, but with the greatest impact in children aged 0-4 and adults 18-64. These estimates of impact depend on assumptions about total incidence of infection and would be larger if incidence of symptomatic infection were higher or shifted toward adults, if viral virulence increased, or if suboptimal treatment resulted from stress on the health care system; numbers would decrease if the total proportion of the population symptomatically infected were lower than assumed.

译文

背景: 需要准确测量大流行性 (H1N1) 2009 流感 (pH1N1) 的严重程度,以评估北半球秋季预期复苏的可能影响。严重程度很难衡量,因为有大量死亡和其他严重后果的司法管辖区有太多病例,无法自信地评估总数。此外,严重病例的检测可能更有可能,导致对平均病例严重程度的高估。我们试图通过结合来自多个来源的数据来估计症状性感染会导致住院、 ICU 入院和死亡的概率。方法和结果: 我们使用了来自美国两个城市的补充数据: 密尔沃基试图确定是否需要住院治疗的医疗感染病例,而纽约市则侧重于确定住院治疗, 重症监护入院或机械通气 (以下简称 ICU),以及死亡。纽约的数据被用来估计重症监护室和死亡的分子,以及两个数据来源 -- 密尔沃基的医学就诊病例或自我报告的流感样疾病 (ILI) 在纽约 -- 被用来估计有症状的病例与住院的比率。结合这些数据和对每个严重程度检测到的分数的估计,我们估计了死亡的有症状病人的比例 (有症状的病例-死亡率,sCFR),要求的 ICU (sCIR), 和按年龄分类的住院治疗 (sCHR)。在贝叶斯证据综合框架中分析证据、先验信息和相关不确定性。使用医学参与的病例和医学参与的症状病例比例的估计值,我们估计 sCFR 为 0.048% (95% 可信区间 [CI] 0.026%-0.096%), sCIR 为 0.239% (0.134%-0.458%),sCHR 为 1.44% (0.83%-2.64%)。使用自我报告的 ILI,我们获得了大约 7-9 倍的估计值。SCFR 和 sCIR 似乎在 18 岁及以上的人群中最高,在 5-17 岁的儿童中最低。SCHR 在 5-17 岁的人群中似乎是最低的; 我们的数据太稀疏,无法确定最高的群体。结论: 这些估计表明,pH1N1 的秋冬季大流行浪潮,每个病例的严重程度相当,可能导致大量死亡,从与季节性流感相关的大大低于到略高, 但对 0-4 岁儿童和 18-64 岁成人的影响最大。这些影响的估计取决于关于感染总发生率的假设,如果症状性感染的发生率更高或转移到成人身上,如果病毒毒性增加,影响会更大, 或者如果医疗保健系统的压力导致了次优的治疗;如果有症状的受感染人口的总数比例低于假设,人数将会减少。

influenza A(H1N1)

呼吸 急性呼吸道传染病 疾病
概述  :  

疾病概述甲型H1N1流感是由新型的甲型H1N1流感病毒感染所致的急性呼吸道传染病。初始世界卫生组织(WHO)将此型流感称为“人感染猪流感”,后将其更名为“甲型H1N1流感”。 发病机制与病理解剖甲型H1N1流感的发病机制与流行性感冒发病机制基本一致。主要病理改变为肺部广泛的炎症和水肿,偶可见上皮坏死和岀血。发生急性呼吸窘迫综合征的病例表现为支气管壁坏死、弥漫性肺泡损害伴肺透明膜病变。肺外脏器如心、肾、肝、脾和骨髓也可受损。 临床表现潜伏期一般为 1-7天,多为 1-

influenza A(H1N1)   /ˌɪnfluˈenzə/

释    义   甲型H1N1流感

例    句   The current flu vaccine does not cover the influenza A (H1N1). If you have any questions about the flu vaccine, please consult with your physician. 目前的流感疫苗并不能产生针对甲型流感病毒(H1N1)的抗性。如果你对流感疫苗有问题,请咨询你的医生。

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