Federal officials are continuing to investigate an outbreak of Salmonella Oranienburg infections traced to whole, fresh onions from Mexico, but the outbreak has been declared over with more than 1,000 people sickened.

In an update today the Centers for Disease Control and Prevention announced that, as of Jan. 20, a total of 1,040 people from 39 states, the District of Columbia and Puerto Rico had been infected. Illnesses started on dates ranging from May 31, 2021, to Jan. 1, 2022

No one died, but of 778 people with information available there were 260 so sick they had to be admitted to hospitals. That is a higher hospitalization rate than is usually seen in Salmonella outbreaks. Sick people ranged in age from less than 1 year to 101 years old.

Prior to today’s update the CDC had not released any outbreak information since Nov. 12, 2021, when it reported 892 people had been infected with the outbreak strain of Salmonella Oranienburg.

The Food and Drug Administration is continuing to work with the U.S. importing forms of  ProSource Produce LLC and Keeler Family Farms to determine whether proper foreign supplier precautions were undertaken. Some of the onions were sold in unmarked bulk bins at retailers.

“In September 2021, as part of the ongoing investigation to determine the product causing illnesses, the FDA import operations implemented enhanced screening for Salmonella for onions imported into the United States, but no samples were collected because the growing season had ended and onions were no longer being imported from the State of Chihuahua, Mexico,” according to an FDA statement today.

“As a result of this outbreak, the FDA initiated onsite domestic investigations as well as Foreign Supplier Verification Program (FSVP) inspections of domestic firms who imported onions from the State of Chihuahua, Mexico. By inspecting these U.S. importers, FDA can determine if they are in compliance with applicable FSVP requirements, including performing certain risk-based activities to verify that imported foods meet U.S. safety standards.”

The FDA is continuing to work with Mexican authorities through the established Food Safety Partnership to investigate potential sources of contamination within the implicated region. The goal is to implement prevention strategies before the next growing season. FDA also intends to consider using additional tools, such as import screening and sampling, for onions grown and harvested in the State of Chihuahua, Mexico, during the next growing season.

The CDC reports that more people than were reported were likely sickened in the outbreak because many people infected with foodborne pathogens do not seek medical treatment or the specific laboratory tests required to diagnose such infections. 

Also, additional sick people could be identified because it can take more than four weeks for patients to be tested, confirmed and reported to federal officials.

Public health officials from state and local levels interviewed some of the sick people and of the 407 people with information available, three-fourths reported eating dishes with raw onions before becoming ill.

On Oct. 20, 2021, ProSource Produce LLC issued a recall. On Oct. 22, 2021, Keeler Family Farms issued. Additional recalls of onions packaged under different brands and used as ingredients on other foods were issued by multiple companies.

Because the most recent person to become ill had illness onset in January, the CDC urges anyone who has eaten raw onions or dishes containing them to be aware of the symptoms of Salmonella and seek medical attention if they develop symptoms.

About Salmonella infections
Food contaminated with Salmonella bacteria does not necessarily look, smell, or taste spoiled. Anyone can become sick with a Salmonella infection. 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 fresh onions 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 require hospitalization.

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.

Some people get infected without getting sick or showing any symptoms. However, they may still spread the infections to others.

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