If a new subvariant were to have created a new Covid-19 outbreak, it probably would have shown up by now in the wastewater — and it hasn’t, according to the man who checks.

That man is Yale environmental engineering professor Jordan Peccia. He leads the team that during the pandemic has been conducting weekly analysis of New Haven-area wastewater — the most reliable early-warning measure of the coronavirus’s trajectory. More reliable than official case numbers or positive-test percentages.

The team has been looking for signs for a new surge of Covid-19 cases forecast based on the emergence a new subvariant of the Omicron variant.

Instead, the team’s latest weekly sample, through April 4, continued to show readings in the range of 5,000 to 6,000 copies of SARS CoV‑2 per milileter of wastewater. The readings have been at that level for weeks, reflecting a slight uptick of cases from a bottoming-out of 2,000.