The figure shows the relative amount of SARS-COV-2 in Gothenburg wastewater week by week, starting mid-February 2020 (week 7). Week numbers on the X-axis.
Photo: Göteborgs universitet

Moderate rise in wastewater coronavirus in Gothenburg


In the latest report on current wastewater concentrations of coronavirus in Gothenburg, a certain increase is noted. This week’s report also concludes the virus monitoring.

Heléne Norder, Institute of Biomedicine, Sahlgrenska Academy at the University of Gothenburg.
Photo: Elin Lindström

The latest measurement is based on samples taken last week, November 7–13. As the adjacent diagram shows, there has been a certain upturn.

“In the second week of November, the SARS-CoV-2 level rose slightly. It looks as if there are more variants around now,” notes Heléne Norder, who heads a research group at Sahlgrenska Academy, University of Gothenburg, and oversees virus surveillance.

Norder and her colleagues have been studying SARS-CoV-2 in the local wastewater since February 2020. Their investigations have been conducted in collaboration with Gryaab, the municipally owned company responsible for wastewater treatment in Gothenburg and the surrounding area. Gryaab has sent the scientists one sample a week, comprising samples collected daily.

Forecasting potential

The researchers have been reporting their findings continuously to healthcare providers, the Infection Control Unit in Region Västra Götaland, and the public. For funding reasons, the project is now being wrapped up.

The measurements and analyses have attracted much attention during the pandemic. The research team’s weekly reports have shown both how widespread the SARS-CoV-2 infection has been in the community, and its distribution among diverse variants of the virus.

In a scientific study published in the journal iScience, the team succeeded in establishing that monitoring of viruses in wastewater enables prediction of pandemic trends and the burden of the pandemic on various parts of the healthcare system. This finding is independent of testing capacity in the community and the scope for tracking infections.

Monitoring of other viruses

The study has demonstrated a common pattern in the four pandemic waves of 2020–22. Each has followed a pattern of peaks in SARS-CoV-2 concentrations in wastewater followed by surges in the numbers of newly hospitalized patients within a couple of weeks.

The viral peaks in the wastewater also permitted prediction of increasing pressure on 1177 Vårdguiden, the Swedish telephone and online healthcare service. One to two weeks after a virus peak in the wastewater, more people called in about acute shortness of breath in adults.

The method used in Gothenburg has also made monitoring of other viruses feasible. This has afforded unique scope for rapid detection of ongoing outbreaks. Apart from SARS-CoV-2, the viruses monitored have included norovirus (the “winter vomiting bug”) and astrovirus, a major cause of severe diarrhea, among children.