Excess mortality associated with influenza after the 2009 H1N1 pandemic in a subtropical city in China, 2010–2015

Liu, Xuxiang; Qin, Guoyou; Li, Xiaoru; Zhang, Junqing; Zhao, Kuaile; Hu, Mingxia; Wang, Xiling

doi:10.1016/j.ijid.2017.01.039

Cited by 25 publications

(30 citation statements)

References 24 publications

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“…26 Notably, our study observed that influenza B caused the highest-burden compared with A(H1N1)pdm09 and A(H3N2). This mortality pattern is consistent with those described in studies conducted by China CDC, 5 Beijing CDC and Guangzhou CDC, 6,10 but differs from studies conducted in other regions and countries such as Yancheng, 12 Hefei, 11 Hong Kong, 9 Singapore, 16 South Korea, 27 United States, 15 and New Zealand, 17 where the highest EMR was associated with influenza A(H3N2). The inconsistent severity profile of influenza type/subtypes warrants further investigation in more locations in future studies.…”

Section: Discussionsupporting

confidence: 88%

Mortality burden from seasonal influenza in Chongqing, China, 2012–2018

Qin²,

Ding³

et al. 2020

Human Vaccines & Immunotherapeutics

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Purpose: To estimate influenza-associated excess mortality rates (EMRs) in Chongqing from 2012 to 2018. Methods: We obtained weekly mortality data for all-cause and four underlying causes of death (circulatory and respiratory disease (CRD), pneumonia and influenza (P&I), chronic obstructive pulmonary disease (COPD) and ischemic heart disease (IDH)), and influenza surveillance data, from 2012 to 2018. A negative-binomial regression model was used to estimate influenza-associated EMRs in two age groups (<65 years and ≥65 years). Results: It was estimated that an annual average of 10025 influenza-associated deaths occurred in Chongqing, corresponding to 5.2% of all deaths. The average EMR for all-cause death associated with influenza was 33.5 (95% confidence interval (CI): 31.5-35.6) per 100 000 persons, and in separate causespecific models we attributed 24.7 (95% CI: 23.3-26.0), 0.8 (95% CI: 0.7-0.8), 8.5 (95% CI: 8.1-9.0) and 5.0 (95% CI: 4.7-5.3) per 100 000 persons EMRs to CRD, P&I, COPD and IDH, respectively. The estimated EMR for influenza B virus was 20.6 (95% CI: 20.3-21.0), which was significantly higher than the rates of 5.3 (95% CI: 4.5-6.1) and 7.5 (95% CI: 6.7-8.3) for A(H3N2) and A(H1N1) pdm09 virus, respectively. The estimated EMR was 152.3 (95% CI: 136.1-168.4) for people aged ≥65 years, which was significantly higher than the rate for those aged <65 years (6.8, 95% CI: 6.3-7.2). Conclusions: Influenza was associated with substantial EMRs in Chongqing, especially among elderly people. Influenza B virus caused a relatively higher excess mortality impact compared with A(H1N1) pdm09 and A(H3N2). It is advisable to optimize future seasonal influenza vaccine reimbursement policy in Chongqing to curb disease burden. ARTICLE HISTORY

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Section: Discussionsupporting

confidence: 88%

Mortality burden from seasonal influenza in Chongqing, China, 2012–2018

Qin²,

Ding³

et al. 2020

Human Vaccines & Immunotherapeutics

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“…In this study, the severity order for influenza subtypes/lineages was likely to be influenza A (H3N2) virus, influenza A (H1N1) virus, and influenza B (Yamagata) virus using LAB × ILI as the proxy, which was the same to that of German and Italy [ 29 , 30 ]. The excess P&I mortality rate associated with influenza A (H3N2) in this study was 10.5% and 0.7% of that for Italy and German [ 27 , 30 ], while comparable with that for Hefei [ 23 ]. Differences in the quality of the viral surveillance and death surveillance, as well as socio-economic levels, healthcare systems, population immunity and meteorological conditions, may interact together explain the difference of disease burden estimates in China and other countries [ 31 ].…”

Section: Discussionsupporting

confidence: 51%

“…Our estimate for excess P&I mortality rate associated with influenza (0.23 per 100,000 persons) in Shanghai was lower than estimates from other countries, including Australia, New Zealand, Italy, and Singapore [ 25 – 28 ]. In China, our estimate for Shanghai was comparable with that for Hefei city [ 23 ], while lower than that for Guangzhou [ 16 ], Dalian, Qingdao, and Zhaoyuan cities [ 4 ]. In this study, the severity order for influenza subtypes/lineages was likely to be influenza A (H3N2) virus, influenza A (H1N1) virus, and influenza B (Yamagata) virus using LAB × ILI as the proxy, which was the same to that of German and Italy [ 29 , 30 ].…”

Section: Discussionmentioning

confidence: 53%

“…However, it was hard to quantify to what extent the humidity played a role in influenza virus survival and transmission respectively. We therefore adjusted the absolute humidity as a confounder as previous studies did [ 23 , 39 ]. We did not add temperature in our model to avoid collinearity problem as the correlation between temperature and absolute humidity was over 0.95 in Shanghai.…”

Section: Discussionmentioning

confidence: 99%

“…We derived weekly absolute humidity by combing temperature and dewpoint temperature. Monday was regarded as the beginning of a week [ 23 ]. This study used aggregated data without personal information, so did not require ethical approval.…”

Section: Methodsmentioning

confidence: 99%

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Excess pneumonia and influenza mortality attributable to seasonal influenza in subtropical Shanghai, China

Wang

Chen

et al. 2017

BMC Infect Dis

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BackgroundDisease burden attributable to influenza is substantial in subtropical regions. Our study aims to estimate excess pneumonia and influenza (P&I) mortality associated with influenza by subtypes/lineages in Shanghai, China, 2010–2015.MethodsQuasi-Poisson regression models were fitted to weekly numbers of deaths from causes coded as P&I for Shanghai general and registered population. Three proxies for influenza activity were respectively used as an explanatory variable. Long-term trend, seasonal trend and absolute humidity were adjusted for as confounding factors. The outcome measurements of excess P&I mortality associated with influenza subtypes/lineages were derived by subtracting the baseline mortality from fitted mortality.ResultsExcess P&I mortality associated with influenza were 0.22, 0.30, and 0.23 per 100,000 population for three different proxies in Shanghai general population, lower than those in registered population (0.34, 0.48, and 0.36 per 100,000 population). Influenza B (Victoria) lineage did not contribute to excess P&I mortality (P = 0.206) while influenza B (Yamagata) lineage did (P = 0.044). Influenza-associated P&I mortality was high in the elderly population.ConclusionsSeasonal influenza A virus had a higher P&I mortality than influenza B virus, while B (Yamagata) lineage is the dominant lineage attributable to P&I mortality.Electronic supplementary materialThe online version of this article (10.1186/s12879-017-2863-1) contains supplementary material, which is available to authorized users.

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