This study aimed to estimate the cause-, age-, and sex-specific excess mortality associated with influenza and its subtypes and lineages in Guangzhou from 2015 to 2018.
Distributed-lag nonlinear models were fitted to estimate the excess mortality related to influenza subtypes or lineages for different causes of death, age groups, and sex based on daily time-series data for mortality, influenza, and meteorological factors.
A total of 199,777 death certificates were included in the study. The average annual influenza-associated excess mortality rate (EMR) was 25.06 (95% empirical CI [eCI] 19.85-30.16) per 100,000 persons; 7142 of 8791 (81.2%) deaths were due to respiratory or cardiovascular mortality (EMR 20.36, 95% eCI 16.75-23.74). Excess respiratory and cardiovascular deaths in people aged 60 to 79 years and those aged ≥80 years accounted for 32.9% (2346/7142) and 63.7% (4549/7142) of deaths, respectively. The male to female ratio (MFR) of excess death from respiratory diseases was 1.34 (95% CI 1.17-1.54), while the MFR for excess death from cardiovascular disease was 0.72 (95% CI 0.63-0.82). The average annual excess respiratory and cardiovascular mortality rates attributed to influenza A (H3N2), B/Yamagata, B/Victoria, and A (H1N1) were 8.47 (95% eCI 6.60-10.30), 5.81 (95% eCI 3.35-8.25), 3.68 (95% eCI 0.81-6.49), and 2.83 (95% eCI -1.26 to 6.71), respectively. Among these influenza subtypes/lineages, A (H3N2) had the highest excess respiratory and cardiovascular mortality rates for people aged 60 to 79 years (20.22, 95% eCI 14.56-25.63) and ≥80 years (180.15, 95% eCI 130.75-227.38), while younger people were more affected by A (H1N1), with an EMR of 1.29 (95% eCI 0.07-2.32). The mortality displacement of influenza A (H1N1), A (H3N2), and B/Yamagata was 2 to 5 days, but 5 to 13 days for B/Victoria.
Influenza was associated with substantial mortality in Guangzhou, occurring predominantly in the elderly, even after considering mortality displacement. The mortality burden of influenza B, particularly B/Yamagata, cannot be ignored. Contrasting sex differences were found in influenza-associated excess mortality from respiratory diseases and from cardiovascular diseases; the underlying mechanisms need to be investigated in future studies. Our findings can help us better understand the magnitude and time-course of the effect of influenza on mortality and inform targeted interventions for mitigating the influenza mortality burden, such as immunizations with quadrivalent vaccines (especially for older people), behavioral campaigns, and treatment strategies.
目的:本研究旨在估计年龄-,2015年至2018年广州与流感及其亚型和谱系相关的特定性别超额死亡率。
方法:拟合了分布滞后非线性模型,以估计与不同死亡原因的流感亚型或谱系相关的超额死亡率。年龄组,和性别基于每日死亡率的时间序列数据,流感,和气象因素。
结果:本研究共纳入199,777份死亡证明。与流感相关的年平均超额死亡率(EMR)为25.06(95%经验CI[eCI]19.85-30.16)/100,000人;8791例死亡中有7142例(81.2%)是由于呼吸或心血管死亡率(EMR20.36,95%eCI16.75-23.74)。60至79岁和≥80岁人群的呼吸和心血管死亡人数占死亡人数的32.9%(2346/7142)和63.7%(4549/7142)。分别。呼吸系统疾病死亡的男女比例(MFR)为1.34(95%CI1.17-1.54),而心血管疾病过度死亡的MFR为0.72(95%CI0.63-0.82).甲型流感(H3N2)导致的年平均呼吸和心血管死亡率B/Yamagata,B/维多利亚,A(H1N1)为8.47(95%eCI6.60-10.30),5.81(95%eCI3.35-8.25),3.68(95%eCI0.81-6.49),和2.83(95%eCI-1.26至6.71),分别。在这些流感亚型/谱系中,A(H3N2)在60至79岁(20.22,95%eCI14.56-25.63)和≥80岁(180.15,95%eCI130.75-227.38)的人群中,呼吸和心血管死亡率最高,虽然年轻人更容易受到甲型H1N1流感的影响,EMR为1.29(95%eCI0.07-2.32)。甲型H1N1流感的死亡率,A(H3N2),B/Yamagata是2到5天,但是对于B/Victoria来说是5到13天。
结论:广州流感与大量死亡率相关,主要发生在老年人中,即使在考虑死亡率流离失所之后。乙型流感的死亡负担,特别是B/Yamagata,不能忽视。在呼吸道疾病和心血管疾病的流感相关死亡率中发现了相反的性别差异;潜在的机制需要在未来的研究中进行研究。我们的研究结果可以帮助我们更好地了解流感对死亡率影响的程度和时间进程,并为减轻流感死亡负担提供有针对性的干预措施。例如四价疫苗的免疫接种(特别是对于老年人),行为运动,和治疗策略。