The burden of seasonal influenza in Italy: a systematic review of influenza-related complications, hospitalizations, and mortality

Abstract

Background: reliable country-specific data on influenza burden play a crucial role in informing prevention and control measures. Our purpose was to provide a comprehensive summary of the available evidence on the burden of seasonal influenza in Italy. Methods: we performed a sys-tematic literature review of articles published until 31 July 2020. PubMed, Embase and Web of Science were searched using terms related to burden, influenza, and Italian population. We in-cluded studies investigating seasonal influenza-related complications, hospitalizations and/or mortality. Results: sixteen studies were included: eight (50%) analyzed influenza-related compli-cations, eight (50%) hospitalizations, while seven (43.8%) influenza-related deaths. Only three studies (19.7%) concerned pediatric age. The synthesis of results showed that patients with chron-ic conditions have an increased risk for complications up to almost three times as compared to healthy people. Hospitalizations due to influenza can occur in as much as 5% of infected people depending on the study setting. Excess deaths rates were over six-fold higher in the elderly as compared to the rest of population. Conclusions: although there are still gaps in existing data, there is evidence of the significant burden that influenza places each year especially on high-risk groups. These data should be used to inform public health decision-making.

Seasonal influenza in children: Costs for the health system and society in Europe

“…Furthermore, influenza can exacerbate underlying chronic conditions like diabetes, pulmonary and cardiovascular diseases 21 . Evidence suggests that influenza complications occur more frequently and are more severe in vulnerable groups such as the elderly and younger children (<5 years of age) 15 . In addition to the common flu complications, young children are also susceptible to further complications of the non‐respiratory tract, notably cardiovascular ones 30 .…”

“…21 Evidence suggests that influenza complications occur more frequently and are more severe in vulnerable groups such as the elderly and younger children (<5 years of age). 15 In addition to the common flu complications, young children are also susceptible to further complications of the non-respiratory tract, notably cardiovascular ones. 30 Although less common, hospitalization for both respiratory and non-respiratory influenza related complications could be expensive.…”

“…[9][10][11] The literature suggests that influenza vaccination of young children may reduce disease rates in non-immunized individuals in the local community. [12][13][14] Furthermore, although most influenzarelated complications and deaths occur among the elderly and people with underlying chronic conditions, 15 children younger than 5 years of age are at high risk of developing serious influenza-associated disease, with indirect impact on their siblings and parents. 8 Actually, worldwide, each year approximately 870,000 children under 5 years of age have a hospitalization attributable to influenza, and it is estimated that between 28,000 and 111,500 deaths in this age group are attributable to influenza-related causes, the vast majority of which occur in developing countries.…”