Multistate outbreak of Listeria monocytogenes linked to Blue Bell Ice Cream; Recommendation to test patients at increased risk of invasive listeriosis who have compatible symptoms

Healthcare providers should test patients who have fever and other symptoms consistent with listeriosis, are at increased risk of invasive listeriosis, and may have been exposed to Listeria through a potentially contaminated product. Diagnostic testing should include cultures of blood and other specimens, such as cerebrospinal fluid, as indicated by the clinical presentation.

People at high risk for invasive listeriosis include pregnant women, adults 65 and older, and people with weakened immune systems. The incubation period for invasive Listeria infection is typically a few days to one month, but can be up to 70 days. Symptoms may include fever and muscle aches, sometimes preceded by diarrhea and other gastrointestinal symptoms.

Persons who have consumed any recalled Blue Bell Creameries products are at risk of exposure. Exact product descriptions and codes for recalled products can be found at

Additional products not subject to the recall but made at the company’s Oklahoma facility might also potentially pose a risk. Blue Bell brand products made at the Oklahoma facility can be identified by checking for letters “O,” “P,” “Q,” “R,” “S,” and “T” following the ”code date” printed on the bottom of the product package.

DSHS is providing the accompanying CDC guidance document, “Suggested framework for medical management of people at elevated risk for invasive listeriosis who are exposed to Listeria monocytogenes,” as a resource for healthcare providers. Although the guidance document suggests stool culture as an option, it is important to note that stool testing for Listeria has not been evaluated as a screening tool for listeriosis. In general, it is not recommended for the diagnosis of listeriosis.

Healthcare providers and laboratories should promptly report confirmed listeriosis cases to their local health department or the Texas Department of State Health Services (Phone: 1-800-705-8868, Fax: 512-776-7616). All Listeria monocytogenes isolates should be sent to the DSHS laboratory.

Information about the Listeria outbreak linked to Blue Bell Ice Cream is available at: