Coronavirus (Covid-19) Infection Survey Northern Ireland – 17 - 23 October 2020

Date published: 30 October 2020

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 NI for the week up to the 23 October 2020. 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).

Key Findings:

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 (17-23 October), it is estimated that 24,300 people in Northern Ireland had COVID-19 (95% credible interval: 12,600 to 43,700).
  • This equates to 1.32% of the population (95% credible interval: 0.68% to 2.38%) or around 1 in 80 people (95% credible interval 1 in 150 to 1 in 40).
  • This is based on statistical modelling of the trend in rates of positive nose and throat swab results which suggests that the number of COVID-19 cases in Northern Ireland has increased in recent weeks.
  • In the latest six-week period, there were 11,624 swab tests in total, and 54 people tested positive from 39 households.
  • In the latest two-week period, there were 4,109 swab tests in total, and 42 people tested positive from 30 households.


Notes to editors: 

  1. 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.
  2. 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.
  3. 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.
  4. 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.
  5. 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.
  6. Further information about quality and methodology associated with the survey can be found on the ONS website.
  7. This publication is available online
  8. Additional information is available from:

Information Analysis Directorate

Department of Health

Annex 2, Castle Buildings


Belfast BT4 3SQ

Telephone:028 9052 2340


9. For media queries please contact DoH Press Office by email:

10. Follow us on twitter @healthdpt.

11. The Executive Information Service operates an out of hours service for media enquiries between 1800hrs and 0800hrs Monday to Friday and at weekends and public holidays. The duty press officer can be contacted on 028 9037 8110.

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