After years of largely predictable norovirus waves, the emergence of a new strain might have disrupted the seasonal pattern of outbreaks from this notorious stomach bug, suggests a new report by the Centers for Disease Control and Prevention.
In previous years, the U.S. usually saw norovirus outbreaks increase around December. That marked the start of the season for the virus. But last year’s season started in October, as a new norovirus strain called GII.17 drove a record wave of outbreaks.
“Continued surveillance is needed to determine if this genotype remains the dominant genotype, as well as whether the norovirus season continues to start earlier than previous years,” wrote two of the CDC’s top norovirus researchers, in an article published this month by the agency’s Emerging Infectious Diseases journal.