The CDC and public health and regulatory officials in California, Nevada, Alaska, Illinois and New Hampshire are investigating a multistate outbreak of Vibrio parahaemolyticus, Shigella flexneri, STEC non-O157, Vibrio albensis, Campylobacter lari, and norovirus genogroup 1 illnesses linked to raw oysters harvested from Estero El Cardon estuary in Baja California Sur, Mexico. On May 6, one U.S. distributor of oysters harvested from Estero El Cardon issued a voluntary recall  On May 7, Estero El Cardon was closed to further oyster harvesting pending investigation.

Epidemiologic and traceback evidence for these cases indicated people ate raw oysters harvested from Estero El Cardon in Baja California Sur, Mexico. State public health officials identified additional illnesses among people who also ate raw oysters from the same harvest area.

As of May 10, 2019, 16 ill people have been reported from five states. Ill people in this outbreak have been infected with multiple pathogens causing illness, including Vibrio parahaemolyticus, Shigella flexneri, STEC non-O157, Vibrio albensis, Campylobacter lari, and norovirus genogroup 1.

In interviews, ill people answered questions about the foods they ate and other exposures in the week before they became ill. All 15 people who were interviewed reported eating raw oysters from different restaurants in California and Nevada. State health officials collected traceback information for 15 cases and found that oysters were shipped by SOL AZUL, S.A. DE C.V. (MX 01 SS) and harvested from Estero El Cardon (an estuary).

Illnesses started on dates ranging from December 16, 2018 to April 4, 2019. Among 15 people with information available, ages range from 26 to 80 years, with a median age of 38. Sixty-seven percent are male. Of 15 people with clinical information available, 2 (13%) hospitalizations were reported. Illnesses might not yet be reported due to the time it takes between when a person becomes ill and when the illness is reported. This can take 4 or more weeks.