The CDC is investigating an outbreak of Salmonella Mbandaka infections that are linked to contact with backyard poultry.

Information from the Centers of Disease Control and Prevention says at least seven people across six states have been infected. In previous years, outbreaks that have begun in the spring have grown to include hundreds of patients.

As of this week, sick people have been reported in Florida, Illinois, Missouri, South Dakota, Utah and Wisconsin. The true number of sick people is likely much higher because for every person confirmed as a patient in a Salmonella outbreak there are 29 who go unreported, according to CDC statistics. This is because some people do not seek medical attention and others are not specifically tested for Salmonella infection because it can mimic other illnesses.

The CDC reported that the illnesses in the outbreak are most likely not limited to the states currently reporting sick people. Illnesses started on dates ranging from Feb. 9 to March 24. It can take four weeks or more for illnesses to be confirmed and reported to federal officials. The sick people in the current outbreak range in age from less than 1 to 55 years old. The median age is five years old, with 43 percent of the patients being younger than 5.

Salmonella infections from backyard flocks come from contact with the birds, their food, eggs, litter and tools. The pathogen can be transferred inside homes. Small children are particularly susceptible to infection because their immune systems are not fully developed and they frequently nuzzle birds and their chicks. 

State and local public health officials are interviewing people about the animals they had contact with in the week before they got sick. Of the seven people with information about animal contact, five reported contact with backyard poultry before getting sick.

A lab in Ohio has found the outbreak strain of Salmonella on poultry shipping materials. The CDC reports that the outbreak strain has also been found at two hatcheries implicated in past outbreaks. One facility is linked to a positive poultry shipping material sample collected by Ohio health officials from the current outbreak that matches the samples from patients in the current outbreak. The CDC said that additional hatcheries may be linked to the outbreak.

Public health investigators are using the PulseNet system to identify illnesses that may be part of this outbreak. CDC PulseNet manages a national database of DNA fingerprints of bacteria that cause gastrointestinal illnesses. DNA fingerprinting is performed on bacteria using a method called whole genome sequencing (WGS). WGS showed that bacteria from sick people’s samples are closely related genetically. This means that people in this outbreak likely got sick from the same type of animal.

Tips from the CDC

• Always wash your hands for 20 seconds after touching birds, their supplies, or collecting eggs. 


• Use a pair of dedicated shoes or boots for your coop and do not wear them inside your house. 


• Keep birds and supplies outside the house to prevent spreading germs into your house. 


• Protect young children, who are more likely to put items in their mouths or not wash hands fully, from getting sick as their immune systems are still developing. Do not let children younger than 5 years old touch the birds, including chicks and ducklings, or anything in the area.