Coronavirus prediction based on sewage

Coronavirus prediction based on sewage

SENDAI - A project to predict the spread of the coronaviruses by looking at sewage is being carried out by a group at Tohoku University's School of Engineering.

A potential sixth infection wave emerges, the team estimates new case numbers for the coming week based on virus amounts in sewage. It hopes local governments will use the information to secure adequate hospital bed numbers.

Since August 2020, the research group has been looking at the concentrations of viruses in waste water, led by professor Daisuke Sano. Samples are taken twice weekly for analysis at a treatment plant that about 70% of the city of Sendai's sewage flows to.

There was a correlation between detected virus amounts and new infection cases from the third to fifth waves. A computational model based on the data was built with machine learning to generate predictions for the next week's new case numbers.

When one in 10,000 people is infected, the virus is detectable in sewage. Its latest forecast released on November 22 showed that 25 new cases were expected between Nov. 22 and Nov. 28. Although the system is still in the testing stage, comparing the results with past projections allows for increasing or decreasing trends to be seen. Sano and other researchers have noticed links between noroviruses concentrations in sewage water and noroviruses patient numbers. Since 2017, they have been working with the Sendai Municipal Government to release data on noroviruses in waste water via a dedicated website. Since Nov. 8, coronavirus prediction results have been sent to a mailing list with about 2,000 registered users.

Actual new infection totals tend to come in lower than the projections due to the progression of vaccines and the spread of correct mask usage. In the future, the actual data will be reflected in the calculation model to improve its accuracy.

Sano said that in countries including South Korea and Germany, infections among older people have risen as the passage of time has reduced the effectiveness of their second vaccine shots.

In Sendai, elderly people vaccinated in May and June may see their shots' efficacy start to fade around December. New case numbers may approach predicted levels if third shots aren't administered.