Problems have come at both ends of the process — the collections of samples from the county's three major sewage plants and the analysis of it by Biobot.
When sampling started in March, the results were unreliable, with spikes and drops that made no sense when analyzed against the clinical and testing data of COVID-19 patients tracked by the Florida Department of Health, Lynskey said. Biobot admits that its methods needed improvement after it launched the testing program in March.
Until August, Biobot's algorithm was estimating the prevalence of the virus, or how widespread the disease was in the population. Because the lab was still fine-tuning its technology, results were taking as many as two weeks to get back, and the testing program was seen as a work in progress, Lynskey said.
Then in August, Biobot revised its model. It included more information in its analysis, including new research on how the virus behaves in wastewater, and started producing results that showed the occurrence of new cases, which could point to trends, rather than just the proportion of cases in the population at a certain moment. And the company also began processing data much faster, turning tests around in just a few days.
"We've been working with hundreds of communities over several months, so we're in a very different place today in terms of our understanding of lab methodologies, data analysis pipelines of the virus just purely because of the data set that we have amassed," said Newsha Ghaeli, Biobot's president and co-founder. "Our sensitivity levels have changed and improved."
Back in March and April, Biobot would provide data back to communities two weeks after sampling, a result that wasn't actionable at all, she said. Now Biobot can test samples in a day and send back results the next day.
So why isn't Miami-Dade taking advantage of this faster turnaround? There have been delays with its own sampling over the past three weeks, so there was no testing through Biobot or data after October 27. WASD said there were delays receiving kits from Biobot and it's working on getting the testing program back on track.
In Boston, meanwhile, the water and sewer company is making the data available and encouraging officials and the public to use it in conjunction with other information to make decisions about the pandemic.
In July, the Massachusetts Water Resources Authority started posting on its website the results of COVID testing at its Deer Island treatment plant. The results are shared with staff from the Department of Public Health, the Department of Environmental Protection, the Executive Office of Health and Human Services and the Executive Office of Energy and Environmental Affairs, according to MWRA.
"It is important to note that this is a pilot of an evolving science," the website said. "The results from this study will be used by public health officials as an additional tool for the Commonwealth to track how the pandemic is trending in Massachusetts, along with data from clinical tests, hospitalizations, etc."