Testing using the Healgen antibody kits began earlier this week in order to estimate the prevalence of Covid-19 in the Island.
Letters were sent to 700 random households asking them to take part in the testing and results from a total of 438 households and 855 individuals have been recorded – equating to around a 65% response.
And from the testing analysis, figures released by Statistics Jersey indicated that a total of 3,300 Islanders could have contracted the virus.
The report said: ‘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.
‘While 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.
‘While 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.’
There have been 293 confirmed cases of coronavirus in the Island according to the latest government figures, and 25 deaths.
Health Minister Richard Renouf, said: ‘I would like to thank Islanders who took part in the survey, the healthcare workers, who carried out the antibody tests, and Statistics Jersey for their detailed work. It has created a helpful picture of how Covid-19 has spread through our community. It is estimated that about 3,300 Islanders have been infected to date.
‘The fact that only a small proportion of the Island population has been infected shows that we have been successful so far in containing the outbreak.
‘This data will help us to decide how and when to safely lift restrictions. The low levels of infection to date show that a significant proportion of Islanders remain at risk of infection. Therefore, it is important that we do not rush into easing lock down fully, but base our decisions on continued, detailed analysis. We are planning further antibody testing in the weeks to come so we can create a fuller picture of how the virus is moving through the Island.
‘The Government has also committed to increasing the number of Covid-19 tests, which detect whether someone is currently infected with coronavirus, to 500 a day. Both this diagnostic test, and the antibody test, are essential in ensuring that we have the fullest, most up-to-date information. It is this information which will allow us to decide how best to continue responding to the coronavirus pandemic.’
The testing kits are designed to detect whether someone has, or has had, coronavirus.
The report added: ‘The test devices themselves have been subject to testing, both internationally and locally by the Microbiology Department of the General Hospital. It is acknowledged that these devices have limitations. The manufacturer cautions that these devices “should not be used as the sole basis to diagnose or exclude SARS-CoV-2 infection or to inform infection status”.
‘The devices have relatively poor sensitivity, consequently, as many as 1 in 3 of those individuals tested may have a false negative test result. This sensitivity issue can, however, be compensated for in respect of the broad population monitoring that this study is aiming to achieve.
‘Adjustment must be made for such measurement error in order to produce an estimate of the true population level prevalence.’
Dr Ivan Muscat, consultant in Communicable Disease Control added that the tests were not designed to indicate immunity levels but the rate of infection in the Island.
He said: ‘There is currently no evidence to show what level, or length, of immunity this antibody test identifies, but this study is not trying to detect immunity. It is aiming to detect antibodies in order to indicate the level of infection in Jersey up to 24 April.
‘The level of implied infection shown by these initial antibody tests is in line with the ongoing modelling work, and it shows that the assumption that one positive test result is likely to equate to ten actual cases appears to be reasonable.’
