After more than a decade of trending downward, the number of foodborne illness outbreaks per year nationwide has leveled off in recent years.
Such outbreaks — like the recent outbreak of norovirus linked to a Chipotle restaurant in Boston that made as many as 141 people sick — last year made more than 13,200 people sick, sent 714 people to the hospital, and killed 20 people, the data shows.
A total of 866 cases were tallied in 2014, according to data from the US Centers for Disease Control and Prevention.
The data began being collected in 1998. The number of outbreaks peaked in 2000, when 1,405 cases were reported, according the CDC's Foodborne Outbreak Online Database. After that, the number of outbreaks has generally trended downward, reaching a low of 669 cases in 2009, according to the CDC. But there have been 795 or more cases in each of the years since then.
The number of people getting sick from the outbreaks has also leveled off since 2010, the data shows.
In Massachusetts, there were 26 outbreaks last year that made 871 people sick, hospitalized 115, and killed three.
Nationally, norovirus accounted for 286 cases last year, or a third of outbreaks, the data shows. Foodborne norovirus outbreaks made 5,553 ill, hospitalized 65, and killed three.
However, the news website FiveThirtyEight found in an analysis of CDC data that large outbreaks of norovirus, like the one in Boston, are rare.
"Just under 3 percent of the food-related norovirus outbreaks that the Centers for Disease Control and Prevention tracked from 2009 to 2014 sickened 80 or more people," FiveThirtyEight reported. "Only 1.3 percent of outbreaks sickened 140 or more people. Half of all outbreaks sickened 11 or fewer people."