As of this week, 938 people had become infected with salmonella by 2020. Cases have almost doubled in the last month, 473 people have been ill since the latest case report, the CDC.
The alleged culprit in this outbreak is poultry. Public health officials interviewed more than 400 of the people who contracted salmonella and 74% said they had had contact with chicks and ducklings.
Since the first disease was reported in January, the CDC said 15 multistate outbreaks were identified. So far, three of them, found in Kentucky and Oregon, have been related to poultry and its ranchers.
The CDC did not speculate why more people became infected in 2020 than in years past. Their timeline of reported cases shows that cases began to increase in late March (cases typically increase in the spring, when poultry farming is most popular, the CDC said).
Chicks and ducks can carry salmonella into their digestive tract, which does not harm them, but they can cause diarrhea, fever, and painful cramps in humans that are exposed to the bacterium in the feathers or eggs of birds or feces.
CNN’s Jen Christensen contributed to this report.