CDC Links Salmonella Outbreak to Wood Ear Mushrooms

Restaurants are being asked to check the source of their mushrooms due to a multistate outbreak of salmonella linked to imported dried wood ear mushrooms.

As of Sept. 24, 41 people have been infected across 10 states. The strain of salmonella responsible for the current mushroom outbreak has sent four people to the hospital, according to the U.S. Centers for Disease Control and Prevention (CDC).

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Of the infected people interviewed, 89 percent said they ate ramen at a restaurant the week before feeling sick. Several reported eating the Japanese noodle soup at the same restaurants, indicating they may be part of illness clusters — two or more people who do not live together reporting illness from eating at the same location.

Packages of recalled mushrooms

FDA

States With Salmonella Cases

•  Arizona
• California
• Connecticut
• Georgia
• Illinois
• Louisiana
• New Jersey
• New York
• Pennsylvania
• Wisconsin

Source: CDC

Shirakiku brand black fungus (kikurage) mushrooms sold to restaurants in five-pound bags from Wismettac Asian Foods of Santa Fe Springs, California, have been identified by the CDC as the likely source of the outbreak. None of the mushrooms were sold directly to consumers. On Sept. 23, Wismettac issued a voluntary recall of the mushrooms, which were imported from China, according to the Food and Drug Administration (FDA). The recalled mushrooms were distributed to restaurants in 31 states, the District of Columbia and Canada.

Patrons are encouraged to ask restaurants where their mushrooms are from before ordering, to avoid eating any contaminated food. Dried wood ear mushrooms are also referred to as kikurage, dried fungus, black fungus or mu'er.

The onset of illnesses reported occurred between Jan. 21 and Aug. 26, infecting people ages 2 to 74 years old. But some illnesses might not yet be reported: Reporting takes an average of two to four weeks after someone becomes ill.

Genome sequencing does not predict any antibiotic resistance to these infections, which are being caused by the Stanley strain of salmonella, according to the CDC. There are more than 2,000 strains of salmonella.

Although dried mushrooms should always be prepared in boiling water to kill any pathogens, these recalled mushrooms should be thrown away. All surfaces the product came in contact with — including cutting boards, countertops, utensils and storage bins — should be cleaned and sanitized, the CDC said.

Symptoms of a salmonella infection

Most people who get salmonellosis, the intestinal infection caused by the bacteria, experience diarrhea, fever and stomach cramps. In severe cases, the infection can spread from the intestines to other parts of the body. Symptoms usually begin six hours to six days after infection and can last up to seven days. But in some cases, symptoms appear weeks after infection, or symptoms can persist for weeks, according to the CDC.

A lab test is used to diagnose an infection by looking for the bacteria in a person's stool, body tissue or fluids. Most people infected can recover without antibiotics. However, treatment is recommended for anyone who experiences severe illness. Antibiotics are recommended for adults over 65 (or over 50 if a person has an underlying condition such as heart disease), infants and those with weakened immune systems.