Study compares death toll from Flu vs Covid-19

Around 15,000 people in Spain died from flu in the last two years and between 2,500 and 3,000 were admitted to the ICU, whereas coronavirus has killed 27,136 in a matter of months, according to research by the Instituto de Salud Carlos III.

The National Center for Epidemiology, or CNE of the ISCIII led the research, which defined and analysed the characteristics of influenza epidemics between 2011 and 2018 in Spain and the results were published in the European Centre for Disease Prevention and Control journal, ‘Eurosurveillance’.

The data shows that flu causes high morbidity and mortality every winter and may be responsible for up to 15,000 deaths in the last two seasons.

Influenza epidemics also produced between 500,000 and 700,000 mild cases treated in Primary Care, 35,000-52,000 hospitalisations and 2,500-3,000 laboratory-confirmed ICU admissions.

The Covid-19 epidemic in Spain has caused at least 27,136 deaths, 243,928 infections, 11,619 ICU admissions and 124,631 hospitalisations, so far, according to official Ministry of Health data.

The study is a "map" of how the flu behaved in Spain between 2001 and 2018, by type of virus, season and age and the results could facilitate Public Health actions to try to reduce the influence of the epidemic and its mortality, according to the Carlos III Health Institute.

The research indicates that transmission of the flu virus in the 21st century in Spain is generally higher in children under 15 and was especially prominent during the 2009 pandemic. The seasonal flu epidemic with the highest intensity was in the 2004-2005 season.

After analysing 18 seasons, the study also reveals that the average duration of the annual flu epidemic in Spain is 8.7 weeks, with 4.3 weeks between the beginning of the epidemic and its maximum peak.

In 12 of the 18 seasons analysed, the epidemic began between mid-December and the third week of January.

Researchers say the results provide a better understanding of the seasonal behaviour of influenza viruses.

"This information makes it possible to estimate when the maximum pressure on the health system will be reached during an influenza epidemic, which can facilitate guidance in Public Health measures and resource planning in the most efficient way to reduce morbidity and mortality associated with seasonal epidemics,” said the Researchers.

Lidia Redondo, a Resident of Preventive Medicine and Public Health is the First Author of the study which is led by Researcher, Amparo Larrauri, Coordinator of the CNE's Influenza Surveillance Group.

Scientists from the CIBER of Epidemiology and Public Health, or CIBERESP, the Department of Preventive Medicine of La Paz Hospital, the General Directorate of Public Health in Castilla y León, and the Influenza Surveillance System in Spain, or SVGE, also participated in the study.