The CDC's May 14 update on its three multistate Salmonella outbreaks linked to backyard poultry put the case count at 184, up from 34 in the agency's April 23 print. [1] That is a 5.4-fold increase in roughly two weeks. The outbreaks span 31 states. Fifty-three people have been hospitalized. One has died, in Washington state. Twenty-eight percent of those sickened are children younger than five. The CDC has traced the outbreak strains to five hatcheries. [1]

The three outbreaks are caused by three different Salmonella serotypes: Saintpaul (133 cases, the largest of the three), Enteritidis (32 cases), and Mbandaka (19 cases). [2] What makes the Saintpaul outbreak unusual is the species of bird people are coming into contact with. "Patients included in the Salmonella Saintpaul outbreak have more frequently reported contact with ducklings or ducks, specifically Pekin ducks, versus other outbreaks where most patients reported contact with chicks and chickens," the CDC's investigation summary reads. [2] Of 25 patients with information about the species, 16 — sixty-four percent — specified Pekin ducks.

Kentucky has reported 22 cases, the most of any state. Michigan follows with 21, Wisconsin with 17, and Ohio with 15. [2] Illnesses started on dates ranging from January 17 to April 20. Eighty-seven percent of people who reported owning backyard poultry had purchased their birds since January 1, often from agricultural retail stores. The CDC has not publicly named the five hatcheries; investigators are "working with state partners to notify those facilities, educate new poultry owners and limit further spread." [3]

The trajectory is the third public-health counter the CDC has watched go vertical in two months. The measles counter sits at 1,952 confirmed cases. The drug-overdose counter, the third, has been a slower climb on a higher base. The backyard-poultry counter has gone from 34 to 184 to — if the curve is anything like prior outbreaks — a number that will keep rising as states finish their three-to-four-week reporting lag. The CDC's own language is direct about it: "The true number of sick people in an outbreak is likely much higher than the number reported." [3]

What is unusual is not the existence of a Salmonella outbreak tied to backyard poultry. Those happen most years. A 2026 Journal of Food Protection review counted 9,923 cases of human salmonellosis linked to backyard poultry over the past decade, often with multidrug-resistant strains. [4] One outbreak that ran from late December 2024 to early September 2025 sickened at least 559 people. Children under five represented close to a third of all cases over the fourteen-year analysis period. [4]

What is unusual about this year's print is the rate of growth and the duck cluster. Sixty-four percent of patients with information on their Saintpaul exposure specified Pekin ducks — a breed that arrived at U.S. agricultural retail stores in unusual volumes this spring, according to industry trade press. [5] Of 34 patients whose samples the CDC sequenced last month, all 34 showed possible resistance to at least one antibiotic used to treat Salmonella, and some showed resistance to four others. [3] Antibiotic resistance does not make Salmonella more contagious. It makes the small fraction of cases that require treatment harder to treat.

Brian Ronholm, director of food policy for Consumer Reports and a former USDA food-safety official, told CIDRAP last week that the multi-strain pattern is consistent with retail-level cross-contamination. "Multiple strains can exist in the chicken's gut," he said, "and all those chicks can contaminate the store where they are sold and pass it on to other chicks at the store." [5] The mechanism is not new. The scale, in a culture where suburban and exurban families increasingly keep small backyard flocks, is.

The five hatcheries the CDC has traced have not, as of Tuesday afternoon, been publicly named. The agency says only that it is working with state agencies to notify them. That gap is one of the active questions for the rest of the week — whether disclosure follows containment, or whether disclosure waits on the kind of legal accommodation that hatchery operators have negotiated in past investigations.

Until then, the visible public-health number is 184. The number under it — the unsampled, the untested, the asymptomatic — is the one the CDC is asking the public to recognize without yet seeing.

-- NORA WHITFIELD, Chicago