Epidemiology of COVID-19 in Ireland Frequently Asked Questions

Q1. What does epidemiological data mean?
Epidemiology is the study of the distribution (pattern, frequency) and determinants (risk factors) of health of specified populations. Epidemiological data (also known as ‘epi data’) describes the pattern and frequency of a disease in specified populations. In this case, COVID-19 epi data for Ireland describes the pattern and frequency of the COVID-19 within the Irish population. The Health Protection Surveillance Centre provides comprehensive daily reports outlining the occurrence of COVID-19, specifying the age category, the gender and the location that the disease is being observed in.

Q2. What epidemiological data does HPSC provide relating to COVID-19?
HPSC is Ireland’s specialist agency for Infectious Disease Control. The Epidemiology Team at HPSC are responsible for preparing the daily reports on COVID-19 cases and deaths. These reports are prepared from Monday to Friday (excluding bank holidays) and can be found here. The reports provide a comprehensive breakdown of the number of new and total cases of COVID-19 in Ireland, deaths relating to COVID-19, while also providing information relating to the demographic (age, gender, location) of the cases. HPSC also produce 14-day epidemiology reports of COVID-19 in Ireland, which can be found here.


Q3. Can you describe what death in confirmed/probable/possible case of COVID-19 means?
The case definition for COVID-19 in Ireland has been updated routinely during the pandemic in accordance with the European Centre for Disease Prevention and Control (ECDC) guidance and updates.
• Deaths in confirmed COVID-19 case: A death in a person with laboratory confirmation of COVID-19 infection, irrespective of clinical signs and symptoms (including post mortem).
• Deaths in probable COVID-19 case: A death in a person with probable COVID-19 infection as described in the COVID-19 case definition below
• Deaths in possible/suspect COVID-19 case: See below scenarios for possible /suspect cases which should be reported as COVID-19 deaths.

  • All deaths in patients suspected of having COVID-19 i.e. patients with symptoms clinically compatible with COVID-19 illness. These suspect cases may or may not have been tested for COVID-19 prior to death. These possible COVID-19 deaths include patients with pending COVID-19 laboratory results.
  • All unexplained deaths/sudden deaths in residential facilities with a confirmed/suspected COVID-19 cluster/outbreak of illness unless there is a clear alternative cause of death that cannot be related to COVID-19 disease (e.g. trauma)

A person can be classified as a probable or possible COVID-19 death without laboratory confirmation of COVID-19 based on the criteria for probable and possible cases of COVID-19 as outlined in the case definition linked below.
https://www.hpsc.ie/a-z/respiratory/coronavirus/novelcoronavirus/casedefinitions/

Q4. Is there a time-lag between cases confirmed and clusters confirmed?
Sometimes, it can occur that there is a time-lag between when cases are confirmed and when clusters are confirmed. This can happen as positive individual cases may be identified before a cluster of cases is observed.

Q5. Is a person who travels to Ireland and tests positive while in Ireland considered to be an Irish case?
If someone from another country is diagnosed with an infectious disease in Ireland, they are notified as an Irish case and included in the Irish case count. Their address of residence in Ireland is used as their geographic location within Ireland.

Q6. What is the turn-around time for a test?
Most people will get their test results within 3 days of having a test, but sometimes it can take longer.

Q7.  How many of the COVID-19 cases in Ireland have been hospitalised/are currently in hospital?
The daily epidemiology report which can be found here provides a breakdown of figures for the following:
•    Number of cases
•    Number of cases hospitalised
•    Number of cases in ICU
•    Total number of outbreaks/clusters
•    Number of cases in healthcare workers
•    Gender of cases
•    Median and mean age
•    Type of transmission
•    Outbreak location (ie. Direct provision centre, residential care facility, etc).
•    County by county breakdown

Last updated 6th October 2020