Burden of influenza-associated respiratory hospitalizations in the Americas, 2010–2015

Abstract

Background Despite having influenza vaccination policies and programs, countries in the Americas underutilize seasonal influenza vaccine, in part because of insufficient evidence about severe influenza burden. We aimed to estimate the annual burden of influenza-associated respiratory hospitalizations in the Americas. Methods Thirty-five countries in the Americas with national influenza surveillance were invited to provide monthly laboratory data and hospital discharges for respiratory illness (International Classification of Diseases 10 th edition J codes 0–99) during 2010–2015. In three age-strata (<5, 5–64, and ≥65 years), we estimated the influenza-associated hospitalizations rate by multiplying the monthly number of respiratory hospitalizations by the monthly proportion of influenza-positive samples and dividing by the census population. We used random effects meta-analyses to pool age-group specific rates and extrapolated to countries that did not contribute data, using pooled rates stratified by age group and country characteristics found to be associated with rates. Results Sixteen of 35 countries (46%) contributed primary data to the analyses, representing 79% of the America’s population. The average pooled rate of influenza-associated respiratory hospitalization was 90/100,000 population (95% confidence interval 61–132) among children aged <5 years, 21/100,000 population (13–32) among persons aged 5–64 years, and 141/100,000 population (95–211) among persons aged ≥65 years. We estimated the average annual number of influenza-associated respiratory hospitalizations in the Americas to be 772,000 (95% credible interval 716,000–829,000). Conclusions Influenza-associated respiratory hospitalizations impose a heavy burden on health systems in the Americas. Countries in the Americas should use this information to justify investments in seasonal influenza vaccination—especially among young children and the elderly.

Disease burden and clinical severity of the first pandemic wave of COVID-19 in Wuhan, China

“…The hospitalization rates of COVID-19 in Wuhan were 3.1-fold higher than that of the 2009 influenza pandemic, and 1.8-2.6 times that of seasonal influenza 16,17,18,19 .…”

“…The sCFR of COVID-19 was higher for adults aged ≥60 years than for the other age groups (9.09% vs. 0.36%-1.97%). (Fig.5a-5c and Supplementary Information File 5) In contrast, younger age groups were the most affected segment of the population during the 1918 and 2009 influenza pandemic, while both young and old individuals were the most affected during seasonal influenza epidemics 14,15,16,17,18,19,20,21,22,23,24,25,26 .…”

Disease burden and clinical severity of the first pandemic wave of COVID-19 in Wuhan, China

“…b Rates of hospitalization associated with 2009 pandemic H1N1 influenza, USA (median, range) 16 c Rates of hospitalization associated with seasonal influenza related SARI in Jingzhou, Hubei province, China (median, range) 17 . d Rates of hospitalization associated with seasonal influenza, USA (mean, 95% CI) 18 , 19 .

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“…(Fig. 5a-c and Supplementary Information File 5) In contrast, younger age groups were the most affected segment of the population during the 1918 and 2009 influenza pandemic, while both young and old individuals were the most affected during seasonal influenza epidemics [14][15][16][17][18][19][20][21][22][23][24][25][26] . The HFR (9.77%, 95% CI 9.41-10.10%) and sCHR (46.48%, 95% CI: 39.33-50.93%) were higher for COVID-19 than for the 2009 influenza pandemic (HFR: 2.6% in North America 26 ; sCHR: 1.44% in the USA 25 ) (Supplementary Information Files 3, 5).…”

“…times that of seasonal influenza [16][17][18][19] . Higher hospitalization burden was found among older adults for COVID-19, while the hospital burden was shifted towards children for seasonal influenza in China 17 and the 2009 influenza pandemic in the US 16 .…”