tetano
Editor, Senior Moderator
Proc Natl Acad Sci U S A
. 2021 Apr 6;118(14):e2016623118.
doi: 10.1073/pnas.2016623118.
Overdispersion in COVID-19 increases the effectiveness of limiting nonrepetitive contacts for transmission control
Kim Sneppen[SUP] 1 [/SUP], Bjarke Frost Nielsen[SUP] 2 [/SUP], Robert J Taylor[SUP] 3 [/SUP], Lone Simonsen[SUP] 3 [/SUP]
Affiliations
Abstract
Increasing evidence indicates that superspreading plays a dominant role in COVID-19 transmission. Recent estimates suggest that the dispersion parameter k for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is on the order of 0.1, which corresponds to about 10% of cases being the source of 80% of infections. To investigate how overdispersion might affect the outcome of various mitigation strategies, we developed an agent-based model with a social network that allows transmission through contact in three sectors: "close" (a small, unchanging group of mutual contacts as might be found in a household), "regular" (a larger, unchanging group as might be found in a workplace or school), and "random" (drawn from the entire model population and not repeated regularly). We assigned individual infectivity from a gamma distribution with dispersion parameter k We found that when k was low (i.e., greater heterogeneity, more superspreading events), reducing random sector contacts had a far greater impact on the epidemic trajectory than did reducing regular contacts; when k was high (i.e., less heterogeneity, no superspreading events), that difference disappeared. These results suggest that overdispersion of COVID-19 transmission gives the virus an Achilles' heel: Reducing contacts between people who do not regularly meet would substantially reduce the pandemic, while reducing repeated contacts in defined social groups would be less effective.
Keywords: mitigation strategies; overdispersion; pandemic; social networks; superspreading.
. 2021 Apr 6;118(14):e2016623118.
doi: 10.1073/pnas.2016623118.
Overdispersion in COVID-19 increases the effectiveness of limiting nonrepetitive contacts for transmission control
Kim Sneppen[SUP] 1 [/SUP], Bjarke Frost Nielsen[SUP] 2 [/SUP], Robert J Taylor[SUP] 3 [/SUP], Lone Simonsen[SUP] 3 [/SUP]
Affiliations
- PMID: 33741734
- DOI: 10.1073/pnas.2016623118
Abstract
Increasing evidence indicates that superspreading plays a dominant role in COVID-19 transmission. Recent estimates suggest that the dispersion parameter k for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is on the order of 0.1, which corresponds to about 10% of cases being the source of 80% of infections. To investigate how overdispersion might affect the outcome of various mitigation strategies, we developed an agent-based model with a social network that allows transmission through contact in three sectors: "close" (a small, unchanging group of mutual contacts as might be found in a household), "regular" (a larger, unchanging group as might be found in a workplace or school), and "random" (drawn from the entire model population and not repeated regularly). We assigned individual infectivity from a gamma distribution with dispersion parameter k We found that when k was low (i.e., greater heterogeneity, more superspreading events), reducing random sector contacts had a far greater impact on the epidemic trajectory than did reducing regular contacts; when k was high (i.e., less heterogeneity, no superspreading events), that difference disappeared. These results suggest that overdispersion of COVID-19 transmission gives the virus an Achilles' heel: Reducing contacts between people who do not regularly meet would substantially reduce the pandemic, while reducing repeated contacts in defined social groups would be less effective.
Keywords: mitigation strategies; overdispersion; pandemic; social networks; superspreading.