TY - JOUR
T1 - Assessing the role of imported cases on the establishment of SARS-CoV-2 Delta variant of concern in Bolton, UK
AU - Shingleton, Joseph
AU - Finnie, Thomas
AU - Gent, Nick
AU - Bennett, Emma
N1 - Publisher Copyright:
Copyright © Crown Copyright-UK Health Security Agency, 2022. Published by Cambridge University Press.
PY - 2022/5/12
Y1 - 2022/5/12
N2 - This paper presents a method used to rapidly assess the incursion and the establishment of community transmission of suspected SARS-CoV-2 variant of concern Delta (lineage B.1.617.2) into the UK in April and May 2021. The method described is independent of any genetically sequenced data, and so avoids the inherent lag times involved in sequencing of cases. We show that, between 1 April and 12 May 2021, there was a strong correlation between local authorities with high numbers of imported positive cases from India and high COVID-19 case rates, and that this relationship holds as we look at finer geographic detail. Further, we also show that Bolton was an outlier in the relationship, having the highest COVID-19 case rates despite relatively few importations. We use an artificial neural network trained on demographic data, to show that observed importations in Bolton were consistent with similar areas. Finally, using an SEIR transmission model, we show that imported positive cases were a contributing factor to persistent transmission in a number of local authorities, however they could not account for increased case rates observed in Bolton. As such, the outbreak of Delta variant in Bolton was likely not a result of direct importation from overseas, but rather secondary transmission from other regions within the UK.
AB - This paper presents a method used to rapidly assess the incursion and the establishment of community transmission of suspected SARS-CoV-2 variant of concern Delta (lineage B.1.617.2) into the UK in April and May 2021. The method described is independent of any genetically sequenced data, and so avoids the inherent lag times involved in sequencing of cases. We show that, between 1 April and 12 May 2021, there was a strong correlation between local authorities with high numbers of imported positive cases from India and high COVID-19 case rates, and that this relationship holds as we look at finer geographic detail. Further, we also show that Bolton was an outlier in the relationship, having the highest COVID-19 case rates despite relatively few importations. We use an artificial neural network trained on demographic data, to show that observed importations in Bolton were consistent with similar areas. Finally, using an SEIR transmission model, we show that imported positive cases were a contributing factor to persistent transmission in a number of local authorities, however they could not account for increased case rates observed in Bolton. As such, the outbreak of Delta variant in Bolton was likely not a result of direct importation from overseas, but rather secondary transmission from other regions within the UK.
KW - Covid-19
KW - Infectious Disease
KW - Mathematical Modelling
UR - http://www.scopus.com/inward/record.url?scp=85130689246&partnerID=8YFLogxK
U2 - 10.1017/S0950268821002776
DO - 10.1017/S0950268821002776
M3 - Article
C2 - 35545847
AN - SCOPUS:85130689246
SN - 0950-2688
VL - 150
JO - Epidemiology and Infection
JF - Epidemiology and Infection
M1 - e100
ER -
