Recalled enoki mushrooms have been linked to a listeria outbreak with cases from a 3-year period. ( Photos courtesy Food and Drug Administration; graphic by Amelia Freidline )

(UPDATED) Enoki mushrooms from South Korea have been recalled and investigators are linking them to a multi-year outbreak of Listeria Monocytogenes that has killed four people.

The importer, Sun Hong Foods Inc., Montebello, Calif., recalled the mushrooms March 9 after Michigan Department of Agriculture and Rural Development officials found two samples of the mushrooms were positive for the listeria strain.

According to the Centers for Disease Control and Prevention, public health agencies are using the PulseNet system to identify illnesses linked to the outbreak, using “DNA fingerprinting” through whole genome sequencing. 

The agencies did not report when the deaths occurred. Patients in California, Hawaii and New Jersey died.

The cases traced to the mushrooms have a high rate of hospitalization, with 30 of the 36 patients identified requiring hospitalization, according to the Food and Drug Administration, which released a warning to consumers March 10 to not eat any enoki mushrooms from Sun Hong Foods.

The break tying the cases together came from Michigan health officials, who were following up on an interview with a patient who identified the store and variety of mushroom eaten. Tests on two samples from the store yielded the outbreak strain, according to the CDC.

The Sun Hong Foods mushrooms were sent distributors in California, Florida, Illinois, Oregon, Texas and Washington and then shipped to Asian specialty stores, but they could have been distributed further to other states, according to the FDA. Retailers that received the mushrooms are:

  • J&L Supermarket
  • Jusgo Supermarket
  • ZTao  Market
  • New Sang Supermarket
  • Galleria Market

The mushrooms are in clear plastic packs of 7.05 ounces/200 grams with a green label. The Universal Product Code is 7 426852 625810.

City and state public health officials interviewed patients about foods consumed in the month preceding illness dates — onset dates range from Nov. 2016 to Dec. 13, 2019 — and 12 of 22 reported eating different mushrooms, including enoki, portobello, white, button, crimini, wood ear, maitake and oyster.

According to the CDC, which is reporting cases in 17 states, most of the cases are from 2018. The onset dates and number of cases in that month, were:

  • November 2016, 1;
  • January 2017, 1;
  • June 2017, 3;
  • September 2017, 3;
  • November 2017-April 2018, 9;
  • June-October 2018: 13;
  • January 2019: 1;
  • March 2019: 1;
  • May 2019, 2;
  • September 2019; 1;
  • Dec. 2019; 1.

Note on update: The story has been updated to correct the number of cases reported by the CDC on its timeline.