Surveillance of influenza B severe hospitalized cases during 10 seasons in Catalonia: Does the lineage make a difference?

Abstract

Influenza B viruses circulate in two lineages (B/Victoria and B/Yamagata). Although classically affecting children, recently it has shown a high rate of infection and increased hospitalization in the elderly. To describe and analyze the clinical and epidemiological characteristics of severe hospitalized laboratory-confirmed influenza B virus (SHLCI-B) cases in Catalonia associated with mismatch from Influenza B virus strain included in the trivalent influenza vaccine (TIV). SHLCI-B was registered by the influenza sentinel surveillance system of Catalonia (PIDIRAC) during ten surveillance seasons from 2010 to 2020. Variables age, comorbidities, and vaccination status were recorded. Vaccine effectiveness was estimated as (1-OR) for intensive care unit (ICU) admission. Statistical significance was established at p < 0.05. A total of 1159 SHLCI-B were registered, of these 68.2% (791) corresponded to the 2017-2018 season; 21.8% ( 253) were admitted to ICU and 13.8% (160) were exitus; 62.5% (725) cases occurred in those aged >64 years; most frequent risk factor was cardiovascular disease (35.1%, 407) followed by chronic pulmonary obstructive disease-COPD (24.6%, 285) and diabetes (24.1%, 279). In four seasons, the predominant circulating lineage was B/Victoria, in two seasons the B/Yamagata lineage and four seasons had no IBV activity. Four seasons presented discordance with the strain included within the TIV.

Changes in Epidemiology and Antibiotic Prescription of Influenza: Before and after the Emergence of COVID-19

“…In the Before-2020 group, male sex was more prone to severe disease and ICU admittance. Similarly, in studies performed before COVID-19 by Martinez et al [12], and Ezzine et al [18], male sex was more prevalent among hospitalized patients and patients who died.…”

“…Patients vulnerable to developing severe influenza are considered to be patients > 65 years old with comorbidities such as diabetes mellitus, other chronic conditions such as asthma, chronic kidney disease, chronic heart failure, immunosuppression, and other conditions [ 12 ]. Considering that the new coronavirus pandemic increased awareness of vaccination and other measures to prevent the transmission of respiratory illnesses, we sought to evaluate whether epidemiologic changes to the known pattern have appeared, as data in this aspect are scarce.…”

Is influenza B/Yamagata extinct and what public health implications could this have? An updated literature review and comprehensive assessment of global surveillance databases

“…Of the remaining 587 articles, 547 were discarded for not matching the inclusion criteria (of these, 62 were not further considered since no reported influenza cases were type B), 7 for being based on the WHO FluNet and/or GISAID database, 3 for being previous reports from the GIHSN, and 4 because of overlap with more recent and/or larger articles based on the same data sources. A total of 26 articles were included in the systematic review: their main characteristics are reported in Table 1 [ Soldevila 2022, Murillo-Zamora 2021, Korsun 2021, Panatto 2021, Pablo-Marcos 2020, Miron 2021, Hu 2021, Omer 2022, Olson 2022, Auvinen 2022, Kuzmanovska 2021, Wagatsuma 2022, Heinzinger 2021, Rios-Silva 2022, Suntronwong 2021, da Costa 2022, Melidou 2020, Huang 2022, O’Neill 2022, Kolosova 2022, Peck 2023, Chon 2023, Merced-Morales 2022, Melidou 2022, Sominina 2022, Song 2022 ]. Europe was the most represented area (12 articles, of which 2 reported findings from multiple countries in the WHO European Region), followed by Asia (n=6), North America (n=5), and Oceania and South America (n=1 each).…”

“…In Table 1 , studies were ordered according to the start and the end of the observation period. In two articles, data collection began several years before the start of the COVID-19 pandemic [ Soldevila 2022, Murillo-Zamora 2021 ]: B/Yamagata viruses accounted for a large proportion of all characterized influenza B-positive specimens, but since data stratified by year were not available, it was not possible to assess how many of them were seen after March 1 st , 2020. Ten studies reported data for the Northern hemisphere 2019-2020 influenza season: in only two of these there were B/Yamagata detections, which represented a very minor percentage of all influenza-positive specimens (1 out of 1,683 in Panatto et al, Italy [ Panatto 2021 ], and 6 out of 28,176 in Hu et al, USA [ Hu 2021 ]).…”