Mathematics continues to be a powerful force against COVID-19.
His latest contribution is a sophisticated algorithm, using municipal sanitation systems, to determine key locations in detecting and tracing COVID-19 to its human source, which may be a newly infected person or a hotspot of infected people. Timing is key, say the researchers who created the algorithm, especially as COVID-19 improves in transmission, thanks to emerging variants.
“Being fast is what we want because in the meantime one newly infected person can infect others,” said Oded Berman, professor of operations management and statistics at the University’s Rotman School of Management. from Toronto.
This latest research builds on Professor Berman’s earlier work with co-researchers Richard Larson from the Massachusetts Institute of Technology and Mehdi Nourinejad from York University. The trio initially developed two algorithms to identify prime locations in a sewage system for manual COVID-19 testing and subsequent tracing to the source. Sewers are a rich environment for detecting the presence of the disease upstream, as the genetic remains of its virus are excreted in the stools of infected people for up to a week before they even know they are sick.
Investigators’ new research refines and optimizes this initial work by more accurately modeling the tree network of one-way pipes and manholes of a typical municipal sewer system, and by speeding up the detection / tracing process with automatic sensors. installed in specific manholes, chosen according to an algorithm that is easier to use.
In this scenario, a sensor sends an alert whenever COVID-19 is detected. Manual tests are then carried out at a few glances further upstream, also chosen according to the algorithm, until the final source is located, whether it is a small group of dwellings or a neighborhood. “Hotspot”. Residents of this much smaller area can then be contacted for further testing and isolation if needed, thus limiting potential new outbreaks.
Applying this approach to a sanitation system with 2,000 manholes shows that only seven sensors would need to be installed along the network to detect and trace COVID-19 to its origin in a day.
“The sensors allow us to manually sample a smaller number of manholes than in our previous work and detect infection much earlier,” said Professor Berman.
Although such sensors are not yet available, such technology is under development. Accurate and rapid on-site testing for COVID-19 and field testing to refine the system will also be required.
The results are promising not only for detecting COVID-19, but also other viruses, such as noroviruses which are highly infectious and cause vomiting and diarrhea. It is also possible that the work could be used in monitoring crystal meth labs and illegal bomb production, due to chemical byproducts that end up in the sewage.
Professor Berman typically works on issues of the future, such as the introduction of self-driving cars, making his wastewater research the first time he’s applied his expertise to a pressing global problem.
“It’s exciting to be working on something that is very much needed and that could have the potential to help people soon,” he said. “It’s very different from what I’ve done before.”
The study was recently published in PLOS ONE.