The Department of Health today published the next in the series of weekly results from its COVID-19 Infection Survey (CIS).
The findings set out in this report relate to modelled positivity estimates for Northern Ireland for the week up to the 22 January 2022. The aims of the CIS are to estimate how many people have the infection and the number of new cases that occur over a given time as well as estimating how many people have developed antibodies to COVID-19.
The survey over time will help track the extent of infection and transmission of COVID-19 among people in the community population (those in private residences).
To ensure our latest estimates on positivity are available at the earliest opportunity during this period of high infections, we published our headline results on Wednesday. The analysis in this bulletin provides further breakdowns for the same period and a longer time series.
Due to the relatively small number of tests and positive swab results within our sample, credible intervals are wide and therefore results should be interpreted with caution.
- During the most recent week of the study (16 January – 22 January), it is estimated that 96,500 people in Northern Ireland had COVID-19 (95% credible interval: 81,600 to 112,700).
- This equates to 5.26% of the population (95% credible interval: 4.45% to 6.14%) or around 1 in 20 people (95% credible interval 1 in 20 to 1 in 15).
- Modelling suggests the trend in the percentage of people testing positive was uncertain in the week ending 22 January in Northern Ireland.
- In the latest six-week period, there were 15,384 swab tests taken in total from 11,447 participants. Of these, 563 participants tested positive from 438 different households.
- In the latest two-week period, of the 5,742 participants in the study, 271 tested positive from 208 households.
- The trend in the percentage testing positive was uncertain across all ages in Northern Ireland.
- Since the end of December, infections compatible with the Omicron variant have been the most common in all four UK countries (see below for more information on the variant analysis undertaken).
The World Health Organization (WHO) have defined names for Variants of Concern. These are variants that the UK government has under surveillance. You can find out more in the SARS-CoV-2 variants of concern and variants under investigation in England briefing document (PDF, 2.51MB).
UK Variants of Concern:
- Alpha: B.1.1.7
- Beta: B.1.351
- Gamma: P.1
- Delta: B.1.617.2 and its genetic descendants
- Omicron: B.1.1.529 (which includes sublineages BA.1, BA.2 and BA.3)
The main Omicron variant (BA.1) has changes in one of the three genes that coronavirus swab tests detect, known as the S-gene. This means in cases compatible with this Omicron variant, the S-gene is no longer detected by the current test. When there is a high viral load (for example, when a person is most infectious) absence of the S-gene in combination with the presence of the other two genes (ORF1ab and N-genes) is a reliable indicator of this Omicron variant (BA.1). However, as the viral load decreases (for example, if someone is near the end of their recovery from the infection), the absence of the S-gene is a less reliable indicator of this Omicron variant.
Notes to editors:
- The Department of Health has been working along with the Public Health Agency, Northern Ireland Statistics and Research Agency and the Office for National Statistics (and its various survey partners) to extend the COVID-19 Infection Survey to Northern Ireland. Fieldwork in Northern Ireland began on 27 July 2020.
- All results are provisional and subject to revision. Due to relatively small number of tests and positive swab tests within the sample, credible intervals are wide and therefore results should be interpreted with caution.
- These statistics refer to infections reported in the community (i.e. private households). These figures exclude infections reported in hospitals, care homes and/or other institutional settings.
- Estimates of the total national proportion of the population testing positive for COVID-19 are adjusted to be representative of the population of Northern Ireland that live in private residential households in terms of age, sex and region.
- Weekly reports are to be published with findings from the COVID-19 Infection survey. It is anticipated that new and further analyses will be added to the weekly reports over time.
- Further information about quality and methodology associated with the survey can be found on the ONS website.https://www.ons.gov.uk/peoplepopulationandcommunity/healthandsocialcare/conditionsanddiseases/methodologies/covid19infectionsurveypilotmethodsandfurtherinformation#covid-19-infection-survey
- This publication is available online
- Additional information is available from:
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