Each spring and summer, the United States typically experiences a multistate outbreak of salmonellosis associated with exposure to backyard poultry (BYP). Since March 1, 2026, the Centers for Disease Control and Prevention (CDC) has linked 17 salmonellosis cases among Wisconsin residents to this year’s backyard poultry multistate outbreak. Backyard poultry, like chickens and ducks, can carry Salmonella germs even if they look healthy and clean. These germs can easily spread to anything in the areas where the poultry live and roam.
Timely surveillance is critical to having a thorough investigation. If the CDC links a Salmonella case to the BYP outbreak the Wisconsin Department of Health Services (DHS) Enteric and Waterborne Diseases Unit will reach out to local and Tribal health department (LTHD) investigators assigned to the case in the Wisconsin Electronic Disease Surveillance System (WEDSS) requesting a supplemental interview be completed.
Background on Salmonella in backyard poultry
Salmonellosis, caused by Salmonella bacteria, is a common diarrheal illness in Wisconsin that usually affects the digestive system, and occasionally affects urine, the bloodstream, or other body tissues in humans. Typically, it is spread by eating or drinking food or water with Salmonella bacteria in it, by touching objects with Salmonella germs on them, or by touching poop from infected people or animals.
Backyard poultry, like chickens, ducks, and other poultry can have Salmonella in their intestines. Salmonella can be spread in their droppings and on their bodies (feathers, feet, and beaks) even when they look healthy and clean. The bacteria can then get on their cages, coops, feed, water dishes, and anywhere the birds live and roam. Anyone who touches the birds or who works or plays in the area where the poultry roam is at risk for becoming infected with Salmonella.
The incubation period is usually six to 72 hours after coming into contact with the bacteria but can range from six hours to six days. Symptoms typically include diarrhea (may be bloody), vomiting, stomach cramps, fever, headache, and dehydration.
Guidance to local and Tribal health departments
LTHDs are asked to complete routine surveillance interviews for any salmonellosis cases reported to their jurisdictions as soon as possible. Utilize the General Enteric Follow-up Worksheet for specific Salmonella interview questions. If DHS is notified by the CDC that a Salmonella case is linked to the BYP multistate outbreak, the DHS Enteric and Waterborne Diseases Unit will reach out to LTHD investigators assigned to the case in WEDSS to request that the case be re-interviewed with the CDC’s supplemental questionnaire.
Resources
DHS resources
Salmonellosis Case Reporting and Investigation Protocol, P-01050 (PDF)
Salmonellosis Fact Sheet, P-42088 (PDF)
Salmonella Outbreak Linked to Backyard Poultry, 2026 Investigation
Salmonella and Backyard Poultry, P-01788 (PDF)
CDC resources