A study of municipal wastewater has identified novel coronavirus in samples from Helsinki and Turku, according to the Finnish Institute of Health and Welfare.
The public health agency said that it found no evidence of the virus in weekly monitoring samples in Tampere, Kuopio and Oulu. The most recently-released results are based on samples taken from 24 - 25 May.
The method developed by the THL involves measuring the quantity of RNA, the virus's genetic mass, in samples collected from wastewater treatment plants. The virus' RNA was readily identified in a sample from Viikinmäki in Helsinki, while a small amount was also observed in samples taken from the Kakolanmäki treatment plant in Turku.
"Advance warning of a possible second wave"
THL research specialist Tarja Pitkänen said that the results confirm observations that the coronavirus epidemic is subsiding in Finland. Previous international studies have determined that wastewater can forecast whether or not increasing amounts of the virus are circulating in the population.
"There has been initial information in the Netherlands and the United States that if a peak or rise is detected in wastewater monitoring it would be up to one week earlier than patient diagnostic results," Pitkänen told STT.
According to Pitkänen wastewater analysis would make it possible to have advance warning of a possible second wave of the disease.
"In that case there would be a few days' time to act and for example to focus measures on a regional basis or to at least prepare for the need to provide more patient care," she said.