Leuven’s sewers could help slow spread of virus

Summary

Researchers are to study the city’s waste water in an attempt to spot Covid-19 infections before they become widespread

Prevention, not cure

Scientists in Leuven have begun a pilot project to monitor the presence of coronavirus in the city’s waste water. Their early detection system would allow researchers to map the presence of the virus even before people test positive, and allow the city to react quickly to potential local outbreaks.

Unlike other parts of the country, Leuven has not seen a significant spike in coronavirus infections over the summer, and the pilot project could play an important role in preventing such a spike from occurring.

“Using waste water analysis, we want to detect if and to what extent infections are present, in particular areas or populations, even before this is shown in an increase in the number of people testing positive for Covid-19,” said Professor Bert Aertgeerts of KU Leuven. “In some infected people, virus particles are present in the digestive system. These particles are excreted and so end up in sewer water.”

Measurements will be taken in areas with high building density, or around care homes and student halls where the risk of rapid spreading of the virus is higher. The sewer water must be traceable to a defined source if it is to provide useful data. Based on the concentration of the virus in the water, the team will gain a better overview of the epidemic’s progress and the necessary measures can be taken.

Early warning system

“The sooner we detect where contamination is occurring, the more effectively we can intervene and break through the contamination chain,” said Leuven mayor Mohamed Rouani. “Thanks to this collaboration, we can discover infections in an innovative way even before people feel sick and get tested. We can also detect infected people who do not show any symptoms.”

At certain places in the sewer system, samples will be taken several times a week, to map the evolution of infections in the immediate environment as quickly as possible. A small amount of waste water will be pumped out of the sewer throughout the day so that a representative daily sample is available for each location. The samples will be analysed by KU Leuven’s Rega Institute.

“Early detection can play a crucial role in the fight against the virus,” said Aertgeerts. “The project is now in a test phase, with the aim of validating this approach in the local context. If that works, it’s a fast and relatively inexpensive way for both large areas and for a hospital or care home, for example, to establish an early warning system.”

Photo: Getty Image/Ake Dynamic

The sooner we detect where contamination is occurring, the more effectively we can intervene and break through the contamination chain

- Mohamed Rouani