It is not yet known whether the strain of Salmonella Agbeni that has infected people in at least three states is resistant to antibiotics. But federal food safety officials do know the Duncan Hines cake mix implicated in the outbreak was produced in the United States.

Because of the outbreak, Conagra Foods recalled four flavors of Duncan Hines brand cake mix on Nov. 5. Conagra officials initiated the recall after federal investigators told them Oregon’s public health department found the outbreak strain of Salmonella in a box of Duncan Hines cake mix.

Investigators from the Oregon Health Authority had recently purchased and tested a total of 35 boxes of various flavors of Duncan Hines cake mix in relation to several illnesses reported in their state, a health department spokesman told Food Safety News. None of those samples tested positive for the Salmonella strain found in the Oregon patients. The spokesman said the source of the bacteria that infected those patients remains unknown.

Conagra Foods posted this photo of the Duncan Hines cake mix flavors that are subject to the recall.

However, one of the boxes of cake mix was contaminated with Salmonella Agbeni. As part of their standard procedures, Oregon officials uploaded the Salmonella’s DNA fingerprint to a national database maintained by the U.S. Centers for Disease Control and Prevention. During a routine check against known Salmonella strains that have infected people, the CDC found five patients had been infected recently with same Salmonella bacteria found in the cake mix in Oregon.

“CDC is working with state health departments and FDA to determine if these ill people ate cake or raw cake mix produced by Duncan Hines. Antibiotic resistance testing by CDC’s National Antimicrobial Resistance Monitoring System laboratory is currently underway,” according to the CDC’s outbreak announcement Nov. 7.

The outbreak patients are from Wisconsin, Ohio and Maryland. None of them have required hospitalization, the CDC reported. The first person became ill on June 13. The most recent person to fall ill developed symptoms on Sept. 17. The lab-confirmed patients range in age from 26 to 72 years old.

A spokesperson with the Food and Drug Administration told Food Safety News the manufacturing plant wher the recalled Duncan Hines cake mix was produced is in the United States. The FDA’s outbreak investigation announcement Nov. 5 reported the agency was inspecting the manufacturing plant, but did not indicate wher the plant is located.

Inspectors from FDA are collecting environmental swab samples from the manufacturing plant. They are also collecting finished product samples for testing.

In the meantime, FDA and CDC officials are urging consumers to check their home kitchens for Duncan Hines cake mixes and compare codes on the boxes to determine whether they are part of the recall. (See chart below for those product codes.)

Conagra reported distributing the Duncan Hines cake mixes to retailers nationwide, as well as some foreign countries. The multinational corporation is offering replacement coupons to people who bought the recalled cake mix.

“These products may be available in grocery stores around the U.S., and consumers should check their labels carefully,” according to Conagra’s recall notice.

Advice for consumers
Food that is contaminated with Salmonella bacteria usually does not look, smell or taste spoiled. Anyone can become sick with a Salmonella infection, but infants, children, seniors and people with weakened immune systems are at higher risk of serious illness because their immune systems are fragile, according to the CDC.

Anyone who has eaten any of the recalled products and developed symptoms of Salmonella infection should seek medical attention. Sick people should tell their doctors about the possible exposure to Salmonella bacteria because special tests are necessary to diagnose salmonellosis. Salmonella infection symptoms can mimic other illnesses, frequently leading to misdiagnosis.

Symptoms of Salmonella infection can include diarrhea, abdominal cramps, and fever within 12 to 72 hours after eating contaminated food. Otherwise healthy adults are usually sick for four to seven days. In some cases, however, diarrhea may be so severe that patients need to be hospitalized. 

Older adults, children, pregnant women and people with weakened immune systems, such as cancer patients, are more likely to develop a severe illness and serious, sometimes life-threatening conditions.

It is possible for some people to be infected with the bacteria and to not get sick or show any symptoms, but to still be able to spread the infection to others.