New Delhi, Oct. 2 -- As the fall season begins, COVID-19 cases are rising again across the United States, fueled by the highly contagious XFG "Stratus" variant.

According to the US Centers for Disease Control and Prevention (CDC), national COVID-19 viral activity in wastewater is at a "moderate" level. However, 19 states report "high" or "very high" levels, including California, Connecticut, Delaware, Utah, Nevada, and North Carolina. Other states with rising activity include Alabama, Arkansas, Indiana, Louisiana, Massachusetts, Minnesota, Montana, Nebraska, New York, Oregon, Rhode Island, South Dakota, and Washington.

Wastewater data shows that the Stratus variant now accounts for most of US COVID-19 cases, making it the dominant strai...