In its latest COVID-19 report, Luxembourg's Ministry of Health confirmed that the number of COVID-19 cases had gone up 19% last week compared to the week before.

For the week of 25 to 31 January 2021, the number of residents testing positive for COVID-19 increased from 843 to 999 people (up 19%) over one week. The number of identified contacts remained stable at 2,774, compared to 2,760 the previous week (up 0.5%). The number of PCR tests carried out over one week also increased from 44,417 to 51,337.

As of Sunday 31 January 2021, the number of active infections stood at 2,185 (compared to 2,137 as of 24 January) and the number of people having recovered from the virus increased from 47,027 to 47,964. The number of weekly deaths rose from nine to fourteen, with the average age of those who died standing at 86.

The situation in hospitals remained relatively relaxed, with 55 COVID-19 patients being treated in normal care and thirteen in intensive care, down from 62 and fifteen respectively the previous week.

The two COVID-19 consultation centres (CCC), located in Luxembourg-Kirchberg and Esch-sur-Alzette, have recorded a total of 6,840 visits to date, including 359 visits last week (compared to 283 the previous week).

For the reference period, the effective reproduction rate (RT eff) increased from 1.05% to 1.10% and the positivity rate on all tests performed increased from 1.90% to 1.95% over one week (weekly average). The positivity rate on tests performed through a doctor's prescription (people with symptoms) was 5.19% (up from 4.63%). The incidence rate was 160 cases per 100,000 inhabitants (up from 135) over seven days. 

Compared to the previous week, the incidence rate increased in all age groups, particularly in children aged 0-14 (up 68%) and young adults aged 15-29 (up 26%). The 60-74 age group continued to have an incidence rate that was around half that of the rest of the population. The average age of people diagnosed with COVID-19 dropped to 36.8 years.

For the week of 25 to 31 January, 1,820 people were in isolation (down 1% over one week) and 3,557 were in quarantine (up 43%).

The family circle remained the most frequent context of transmission of COVID-19 infections (43%), followed by the education (8.6%) and healthcare sectors (7%). The source of infection was not clearly attributable in 29.4% of cases (down from 33.7%).

Pilot project

Between 18 and 28 January 2021, the Health Inspectorate carried out a more granular study of the sources and routes of contamination as part of a pilot project, based on a questionnaire on the places frequented during the last fourteen days by infected individuals, the activities carried out during this period and the health measures observed on this occasion. The Contact Tracing Team used this questionnaire team when contacting 584 positive cases by telephone.

The data obtained during this exercise are currently being evaluated, although a preliminary statistical analysis made it possible to make several observations. Firstly, regarding the place of infection; in cases where infected individuals said that they knew the "source" individual (around 50% of cases), contact took place indoors for 74% of them, while in 24% of cases contact took place indoors and outdoors. For only 2%, an exclusively external contact was made. Home, the workplace and essential stores (e.g. supermarkets) were the most often cited places frequented by infected individuals during the fourteen days preceding their positive coronavirus test. Regarding the duration of exposure, most contact took place longer than two hours; contact lasting less than fifteen minutes was rare (4%). In addition, in more than 90% of the cases, the person questioned indicated having spoken directly with his / her contact and in 87% of the cases, they had eaten or drunk together.

Virus mutations

Since the British variant B.1.1.7. began circulating in Luxembourg (19 December 2020), the National Health Laboratory (Laboratoire National de Santé - LNS) has sequenced a total of 791 samples, from which 47 cases have been detected. As for the South African variant B.1.351, whose sequencing began on 11 January 2021, four cases have been detected; the last sequencing dates back to 22 January 2021. 

The health authorities noted that these figures are not representative in nature. Some sequencing has been targeted. For example, among the 93 samples sequenced during the week beginning 18 January, more than 50% were sequenced at the request of the Health Inspectorate as part of Contact Tracing.

The Directorate of Health and the LNS are in the process of implementing the means required to have a representative sampling of the general population based on samples from different regions and age categories with the help medical analysis laboratories. The objective is to have a system for epidemiological monitoring of variants in real time by the end of February.

Vaccinations

For the week of 25 to 31 January, a total of 4,715 vaccine doses were administered in Luxembourg: 4,279 people received their first dose whilst 439 received their second dose.

Wastewater monitoring

The latest CORONASTEP report drawn up by the Luxembourg Institute of Science and Technology (LIST) indicated an average prevalence of the virus in wastewater at the national and regional level. A slight downward trend seemed to continue last week across all the treatment plants analysed.