New measurements of the wastewater in Umeå, Uppsala, Örebro and Kalmar show that omikron has eliminated delta as a virus variant almost completely.

On January 10, omicron accounted for 100 percent of the corona virus in the wastewater in Umeå, Uppsala and Örebro.

Only in Kalmar were there traces of delta left, albeit barely measurable.

This can be compared with zero percent in all cities in the measurements made in week 51 in 2021, which means a sharp increase since Christmas.

- It is fascinating to see how quickly and totally omikron has taken over the playing field.

We fear an even larger increase this week given the effects of starting school and that more people have returned to workplaces, says Maja Malmberg, researcher and virologist at the Swedish University of Agricultural Sciences, SLU.

"Important parameter"

The analyzes are performed by the Swedish Environmental Epidemiology Center, SEEC, with researchers from SLU, KTH, KI and Uppsala University.

Among the places examined are - in addition to Umeå, Uppsala, Örebro and Kalmar - also Stockholm, Enköping, Knivsta and Malmö.

- Now we see that the wastewater reflects the development of the spread of infection in society and in times when the test capacity is not enough, these measurements can be an important parameter to also take into account, says SLU researcher Anna Székely, who has led the work.

Measurements show new outbreaks

It is currently not possible to determine how many people have been infected and what levels of the virus that each person excretes in the wastewater.

But according to Maja Malmberg, the tests so far have followed the development in society and the burden in healthcare.

- There is still a lot we do not know about the connection between virus excretion in faeces and differences, for example between different virus variants, vaccination status or between mild or serious illness.

But despite that, the measurements seem to be good enough to be able to show new outbreaks, she says.

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From toilet visits to test results - we will get answers about omikron.

Follow the treatment plant in Uppsala in the clip.

Photo: Simon Krona / SVT