08 May 2020
Statistics Jersey have today published our preliminary analysis following the completion of a survey of Islanders using Healgen COVID-19 IgG/IgM rapid test cassettes in order to estimate the prevalence of SARS-CoV-2 related antibodies in the Jersey population. Statistics Jersey did not conduct this survey but have been asked to provide an analysis of the results.
Our key finding is that the estimated population prevalence rate of SARS-CoV-2antibodies is:
3.1% ± 1.3% (95% confidence interval)
This prevalence rate is in respect of the adult resident population living in private households in Jersey. The survey did not perform testing on any person aged under 16 years and did not include residents of communal establishments (such as care homes).
Due to the methods employed to obtain this estimate, there is a degree of uncertainty around the prevalence figure, in part reflected by the confidence intervals shown. However, the potential impact of non-response bias should also be considered. The survey achieved an estimated response rate of 65%; there was a significant level of non-response of those Islanders living in non-qualified accommodation.
The estimated prevalence rate implies that the total number of cases of SARS-CoV-2 that have occurred in households living in private accommodation was approximately 2,700. Whilst it is anticipated that there may be differences between this population and those who were excluded from this study, applying the estimated prevalence rate to the full Island population would equate to approximately 3,300 cases having occurred to date.
Whilst there exists a degree of uncertainty around these figures, the results of this analysis, and the above prevalence rate, are in line with the ongoing epidemic modelling currently being conducted.