Virus levels in wastewater have fallen in recent weeks in Gothenburg, Stockholm and Uppsala.

Preliminary results from three different research studies now show that the downward trend has been broken in all three cities.

The amount of coronavirus in wastewater has proven to be an effective method of predicting how many people will develop covid-19.

Predicts the number of patients

Research at Sahlgrenska University Hospital has shown that the number of newly admitted patients with covid-19 increased just over two weeks after a peak of the virus was detected in the wastewater.

It is such an effective method that it is used by Sahlgrenska's hospital management as part of their planning of how the load on the hospital will be in the near future.

- The amount of virus levels of covid-19 in the wastewater has so far relatively well reflected the development of how covid-19 is spread in society, says Cecilia Williams who is a professor of biotechnology from KTH and works at SciLifeLab where she analyzes virus levels in wastewater.

Virus levels increase

The preliminary figures now show that the amount of virus is increasing again in Stockholm's wastewater.

- We are just doing the analysis for the wastewater from last week and it may be an increase on the way, says Cecilia Williams.

The same trend can also be seen in Gothenburg.

Daily preliminary results show an increase in virus levels in the wastewater. 

- Unfortunately, the amount of virus in the wastewater seems to have risen again, not as much as during week 50 and week 2 but about a third by then.

Hopefully it will turn around next week, says Heléne Norder who is a virologist and professor of microbiology at Sahlgrenska University Hospital.

Measurements in Uppsala

In Uppsala, there is also no longer a clear decline in virus levels in wastewater.

- The decline in virus levels in wastewater in January was not as steep as the rise in October, but now the values ​​have stopped falling and stabilized.

Next week's results can show if it means that an increase is underway, says Anna Székely who is a researcher at the Department of Ecology and Genetics at Uppsala University.