tetano
Editor, Senior Moderator
BMC Infect Dis
. 2024 Apr 29;24(1):450.
doi: 10.1186/s12879-024-09343-8. Spatial spread of COVID-19 during the early pandemic phase in Italy
Valeria d'Andrea[SUP] #[/SUP][SUP] 1 2 [/SUP], Filippo Trentini[SUP] #[/SUP][SUP] 1 3 4 [/SUP], Valentina Marziano[SUP] 1 [/SUP], Agnese Zardini[SUP] 1 [/SUP], Mattia Manica[SUP] 1 [/SUP], Giorgio Guzzetta[SUP] 1 [/SUP], Marco Ajelli[SUP] 5 [/SUP], Daniele Petrone[SUP] 6 7 [/SUP], Martina Del Manso[SUP] 6 [/SUP], Chiara Sacco[SUP] 6 [/SUP], Xanthi Andrianou[SUP] 6 [/SUP], Antonino Bella[SUP] 6 [/SUP], Flavia Riccardo[SUP] 6 [/SUP], Patrizio Pezzotti[SUP] #[/SUP][SUP] 6 [/SUP], Piero Poletti[SUP] #[/SUP][SUP] 1 [/SUP], Stefano Merler[SUP] #[/SUP][SUP] 8 [/SUP]
Affiliations
Quantifying the potential spatial spread of an infectious pathogen is key to defining effective containment and control strategies. The aim of this study is to estimate the risk of SARS-CoV-2 transmission at different distances in Italy before the first regional lockdown was imposed, identifying important sources of national spreading. To do this, we leverage on a probabilistic model applied to daily symptomatic cases retrospectively ascertained in each Italian municipality with symptom onset between January 28 and March 7, 2020. Results are validated using a multi-patch dynamic transmission model reproducing the spatiotemporal distribution of identified cases. Our results show that the contribution of short-distance ( ≤10km)
transmission increased from less than 40% in the last week of January to more than 80% in the first week of March 2020. On March 7, 2020, that is the day before the first regional lockdown was imposed, more than 200 local transmission foci were contributing to the spread of SARS-CoV-2 in Italy. At the time, isolation measures imposed only on municipalities with at least ten ascertained cases would have left uncontrolled more than 75% of spillover transmission from the already affected municipalities. In early March, national-wide restrictions were required to curb short-distance transmission of SARS-CoV-2 in Italy.
Keywords: COVID-19; Infection spread; SARS-CoV-2; Spatial diffusion; Spatial model; Transmission distance.
. 2024 Apr 29;24(1):450.
doi: 10.1186/s12879-024-09343-8. Spatial spread of COVID-19 during the early pandemic phase in Italy
Valeria d'Andrea[SUP] #[/SUP][SUP] 1 2 [/SUP], Filippo Trentini[SUP] #[/SUP][SUP] 1 3 4 [/SUP], Valentina Marziano[SUP] 1 [/SUP], Agnese Zardini[SUP] 1 [/SUP], Mattia Manica[SUP] 1 [/SUP], Giorgio Guzzetta[SUP] 1 [/SUP], Marco Ajelli[SUP] 5 [/SUP], Daniele Petrone[SUP] 6 7 [/SUP], Martina Del Manso[SUP] 6 [/SUP], Chiara Sacco[SUP] 6 [/SUP], Xanthi Andrianou[SUP] 6 [/SUP], Antonino Bella[SUP] 6 [/SUP], Flavia Riccardo[SUP] 6 [/SUP], Patrizio Pezzotti[SUP] #[/SUP][SUP] 6 [/SUP], Piero Poletti[SUP] #[/SUP][SUP] 1 [/SUP], Stefano Merler[SUP] #[/SUP][SUP] 8 [/SUP]
Affiliations
- PMID: 38684947
- PMCID: PMC11057115
- DOI: 10.1186/s12879-024-09343-8
Quantifying the potential spatial spread of an infectious pathogen is key to defining effective containment and control strategies. The aim of this study is to estimate the risk of SARS-CoV-2 transmission at different distances in Italy before the first regional lockdown was imposed, identifying important sources of national spreading. To do this, we leverage on a probabilistic model applied to daily symptomatic cases retrospectively ascertained in each Italian municipality with symptom onset between January 28 and March 7, 2020. Results are validated using a multi-patch dynamic transmission model reproducing the spatiotemporal distribution of identified cases. Our results show that the contribution of short-distance ( ≤10km)
transmission increased from less than 40% in the last week of January to more than 80% in the first week of March 2020. On March 7, 2020, that is the day before the first regional lockdown was imposed, more than 200 local transmission foci were contributing to the spread of SARS-CoV-2 in Italy. At the time, isolation measures imposed only on municipalities with at least ten ascertained cases would have left uncontrolled more than 75% of spillover transmission from the already affected municipalities. In early March, national-wide restrictions were required to curb short-distance transmission of SARS-CoV-2 in Italy.
Keywords: COVID-19; Infection spread; SARS-CoV-2; Spatial diffusion; Spatial model; Transmission distance.