This top rating is based on samples taken January 10-16.

Sampling is part of an ongoing research project that is not yet ready for publication, so no exact figures are yet revealed.

- 99 percent is Omikron, ie the milder variant, says Heléne Norder, who leads the research group.

Measurements can replace testing

For four weeks in a row, the samples in the wastewater have shown a sharp increase.

Heléne Norder believes that this type of measurement will become more important in the future if the degree of covid testing changes.

- If we reduce the testing, it is in the wastewater we can see if the infection increases or decreases.