Estimates of influenza‐associated hospitalisations in tropical Singapore, 2010‐2017: Higher burden estimated in more recent years

Abstract

Background We previously estimated Singapore's influenza‐associated hospitalisation rate for pneumonia and influenza (P&I) in 2010‐2012 to be 29.6 per 100 000 person‐years, which corresponds to 11.2% of all P&I hospitalisations. Objectives This study aims to update Singapore's estimates of the influenza‐associated pneumonia and influenza (P&I) hospitalisation burden using the latest data from 2010 to 2017. Methods We estimated the number of P&I hospitalisations associated with influenza using generalised additive models. We specified the weekly number of admissions for P&I and the weekly influenza positivity in the models, along with potential confounders such as weekly respiratory syncytial virus (RSV) positivity and meteorological data. Results In 2010‐2017, 16.3% of all P&I hospitalisations in Singapore were estimated to be attributed to influenza, corresponding to an excess influenza‐associated P&I hospitalisation rate of 50.1 per 100 000 person‐years. Higher excess rates were estimated for children aged 0‐4 years (186.8 per 100 000 person‐years) and elderly aged ≥ 65 years (338.0 per 100 000 person‐years). Higher influenza‐associated hospitalisation rates were estimated for 2016 and 2017 (67.9 and 75.1 per 100 000 persons, respectively) years when the influenza A(H3N2) subtype was dominant. Conclusion Influenza burden in Singapore has increased since 2010. Influenza vaccination programmes should continue to be prioritised for the young and the elderly.

Influenza-associated disease burden in mainland China: a systematic review and meta-analysis

“…our pooled excess all-cause mortality rate (14.33 per 100,000 persons) was similar to those reported in Europe (13.30 per 100,000 persons) 48 and Hong Kong SAR (11.70 per 100,000 persons) 6 , but slightly higher than that reported in the USA (6.96 per 100,000 persons) 49 and South Korea (5.97 per 100,000 persons) 50 . Our influenzaassociated P&I (384 per 100,000 persons) or SARI (442-715 per 100,000 persons) hospitalization rate among children aged < 5 years was much higher than those reported for Singapore (excess P&I hospitalization rate of 186.8 per 100,000 persons) 51 , Portugal (excess P&I hospitalization rate of 42.6 per 100,000 persons) 52 , Chile (excess SARI hospitalization rate of 71.5 per 100, 000 persons) 53 . Children aged < 5 years had the highest excess www.nature.com/scientificreports/ SARI hospitalization rates in China, contrasting with higher rates among adults aged ≥ 65 years in above countries.…”

Evaluation of multi-component interventions for prevention of nosocomial pneumonia in older adults: a randomized, controlled trial

“…Older people with influenza infections have the highest risk of death, highest risk of hospitalisation and the lowest likelihood of admission to ICU compared to younger people [39]. Locally the influenza-associated hospitalisation rate is 16.3%, with a substantially increased excess hospitalisation rates in those age 75 years and above [20] but community uptake of these vaccines is poor as evidenced by the very low pre-study vaccination rates in this aged cohort, 4.9% for prior influenza and 6.5% for prior pneumococcal vaccination [21,40]. The World Health Organisation recommends countries aim achieve influenza vaccination coverage of 75%, but there are major differences across European countries and historically poor uptake in older people [41].…”

“…Locally the influenza-associated hospitalisation rate is 16.3% with substantially increased excess hospitalisation rates in those age 75 years and above [20]. Although guidelines recommend routine vaccination of older adults, vaccination uptake rates are low, with vaccination rates of only 17% for influenza and 6.1% for pneumococcus among older adults in Singapore [21][22][23].…”

Clinical manifestations of adult patients requiring influenza-associated hospitalization: a prospective multicenter cohort study in Japan via internet surveillance

“…Influenza remains a heavy clinical burden worldwide. Recent reports have suggested estimated annual hospitalization rates in various countries varying from 13 to 141 per 100,000 population [5][6][7][8][9][10] . In Japan, 1.0% of influenza-positive patients aged under 75 years were hospitalized between 2012 and 2016 11 .…”