COVID-19 cases - Weekly review: 17 - 23 May

During the week from 17 to 23 May and for the 4th week in a row, the number of people testing positive for COVID-19 continued to decrease from 728 to 495 (-35.0%), while the number of their identified close contacts also decreased from 1,757 cases the previous week to 1,298 (-26.1%).

The number of PCR tests performed during the week of 17 to 23 May has increased significantly from 49,715 to 72,118.

206 people reported a positive rapid antigen test.

As of 23 May, the number of active infections had decreased to 1,283 (compared to 1,727 on 16.05), while the number of people healed increased from 66,547 to 67,483. The average age of those diagnosed as COVID-19 positive remains rather stable at 31.1 years.

The number of new deaths remained the same, with 3 deaths related to COVID-19. The average age of the deceased decreased to 78 years.

In the hospitals, there was a further decrease in admissions of confirmed COVID patients, with 28 hospitalisations in normal care, compared to 43 the previous week. In intensive care, the number of occupied beds also decreased significantly from 29 to 19. The average age of hospitalised patients decreased from 59 to 58 years.

Positivity rate and incidence rate

For the reference period, the effective reproduction rate (R) further decreased from 0.85 to 0.81, while the positivity rate on all tests performed (prescriptions, Large Scale Testing, contact tracing) also decreased from 1.46% to 0.69% (weekly average). A similar trend can be observed for the positivity rate for tests carried out on prescription, i.e. for people with symptoms, which dropped from 3.36% to 1.45%.

The incidence rate continues its downward trend for all age groups, with 78 cases per 100,000 residents over 7 days, compared to 115 cases per 100,000 residents for the week of 10 May. The most significant decrease is recorded in the age group 60-74 years (-53%), followed by the 75+ years (-44%).

The 75+ age group continues to have the lowest incidence rate with 12 cases per 100,000 residents, followed by the age group 60-74 years, with 28 cases per 100,000 residents. The 15-29 years age group continues to have the highest incidence rate with 120 cases per 100,000 residents, followed by the age group 0-14 years, with 104 cases per 100,000 residents. The incidence rate of the 60-74 years and 75+ age groups, main focus of the vaccination campaign, is 5 to 10 times lower than the incidence rate of the 0-14 years and 15-29 years age groups who haven't been vaccinated so far.

Quarantine and isolation

For the week from 17 to 23 May, 1,662 people were in isolation (-18.9%) and 1,898 in quarantine (-29.7% compared to the previous week).


For the 495 new cases, the family circle remains by far the most frequent source of transmission of COVID-19 infections with 40.5%, followed by leisure (6.7%), the education sector (5.6%) and the work place (3.5%). The rate of contamination for which the source is not clearly attributable increased to 39.5%.

Vaccinations: update on the situation

For the week of 17 to 23 May, a total of 34,967 doses were administered. 21,430 people received a 1st dose and 13,537 received a 2nd dose, bringing the total number of vaccines administered until 25 May to 324,903 (1st and 2nd dose). 112,791 people have a complete vaccination pattern.

The evolution of the variants

For the week of 10 to 16 May, the population sequencing coverage was 67.5%, well above the optimal rate of 10% recommended by ECDC in order to have an optimal representative sampling.

Regarding the 630 samples carried out for calendar week 19/2021, the following distribution of variants can be observed:

  • the UK variant (B.1.1.7) represents 79% of the cases;
  • the South African SA variant (B.1.351) represents 5.7% of cases, compared to 7.1% for week 18
  • the Indian variant B.1.617 represents 3.9% of cases, compared to 0.74% for week 18
  • the Brazilian variant (P.1) represents 3.7% of cases, compared to 4.3% for week 18

Wastewater monitoring in Luxembourg as part of SARS-CoV-2

The contamination level of the 13 analysed waste water treatment plants by the LIST (Luxembourg Institute of Science and Technology), during the week of 17 -23 May indicates a continues decrease over the past weeks. This result will have to be confirmed by the analyses performed in the coming weeks.

All CORONASTEP reports are available on the LIST website:

Press release by the Ministry of Health, the Laboratoire national de santé (LNS) and the Luxembourg Institute of Science and Technology (LIST)

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