AUTHOR=Bizzotto Andrea , Guzzetta Giorgio , Marziano Valentina , Del Manso Martina , Mateo Urdiales Alberto , Petrone Daniele , Cannone Andrea , Sacco Chiara , Poletti Piero , Manica Mattia , Zardini Agnese , Trentini Filippo , Fabiani Massimo , Bella Antonino , Riccardo Flavia , Pezzotti Patrizio , Ajelli Marco , Merler Stefano 

TITLE=Increasing situational awareness through nowcasting of the reproduction number

JOURNAL=Frontiers in Public Health

VOLUME=Volume 12 - 2024

YEAR=2024

URL=https://www.frontiersin.org/journals/public-health/articles/10.3389/fpubh.2024.1430920

DOI=10.3389/fpubh.2024.1430920

ISSN=2296-2565

ABSTRACT=Background. The time-varying reproduction number R is a critical variable for situational awareness during infectious disease outbreaks; however, delays between infection and reporting of cases hinder its accurate estimation in real-time. A number of nowcasting methods, leveraging available information on data consolidation delays, have been proposed to mitigate this problem.Methods. In this work, we retrospectively validate the use of a nowcasting algorithm during 18 months of the COVID-19 pandemic in Italy by quantitatively assessing its performance against standard methods for the estimation of R.Results. Nowcasting significantly reduced the median lag in the estimation of R from 13 to 8 days, while concurrently enhancing accuracy. Furthermore, it allowed the detection of periods of epidemic growth with a lead of between 6 and 23 days.Conclusions. Nowcasting augments epidemic awareness, empowering better informed public health responses.