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Estimation of the serial interval and proportion of pre-symptomatic transmission events of COVID− 19 in Ireland using contact tracing data

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Show simple item record McAloon, Conor G. Wall, Patrick Griffin, John Casey, Miriam Barber, Ann Codd, Mary Gormley, Eamonn Butler, Francis McV Messam, Locksley L Walsh, Cathal Dominic Teljeur, Conor Smyth, Breda Nolan, Philip Green, Martin J. O'Grady, Luke Culhane, Kieran Buckley, Claire Carroll, Ciara Doyle, Sarah Martin, Jennifer More, Simon J. 2021-07-06T13:36:18Z 2021-07-06T13:36:18Z 2021
dc.description peer-reviewed en_US
dc.description.abstract Background: The serial interval is the period of time between the onset of symptoms in an infector and an infectee and is an important parameter which can impact on the estimation of the reproduction number. Whilst several parameters influencing infection transmission are expected to be consistent across populations, the serial interval can vary across and within populations over time. Therefore, local estimates are preferable for use in epidemiological models developed at a regional level. We used data collected as part of the national contact tracing process in Ireland to estimate the serial interval of SARS-CoV-2 infection in the Irish population, and to estimate the proportion of transmission events that occurred prior to the onset of symptoms. Results: After data cleaning, the final dataset consisted of 471 infected close contacts from 471 primary cases. The median serial interval was 4 days, mean serial interval was 4.0 (95% confidence intervals 3.7, 4.3) days, whilst the 25th and 75th percentiles were 2 and 6 days respectively. We found that intervals were lower when the primary or secondary case were in the older age cohort (greater than 64 years). Simulating from an incubation period distribution from international literature, we estimated that 67% of transmission events had greater than 50% probability of occurring prior to the onset of symptoms in the infector. Conclusions: Whilst our analysis was based on a large sample size, data were collected for the primary purpose of interrupting transmission chains. Similar to other studies estimating the serial interval, our analysis is restricted to transmission pairs where the infector is known with some degree of certainty. Such pairs may represent more intense contacts with infected individuals than might occur in the overall population. It is therefore possible that our analysis is biased towards shorter serial intervals than the overall population en_US
dc.language.iso eng en_US
dc.publisher BMC en_US
dc.relation.ispartofseries BMC Public Health;21:805
dc.subject COVID-19 en_US
dc.subject SARS-CoV-2 en_US
dc.subject contact tracing en_US
dc.subject serial interval en_US
dc.title Estimation of the serial interval and proportion of pre-symptomatic transmission events of COVID− 19 in Ireland using contact tracing data en_US
dc.type info:eu-repo/semantics/article en_US
dc.type.supercollection all_ul_research en_US
dc.type.supercollection ul_published_reviewed en_US
dc.identifier.doi 10.1186/s12889-021-10868-9
dc.rights.accessrights info:eu-repo/semantics/openAccess en_US

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