Controlling Spread of Listeriosis

Table of Contents

A. Isolation and Quarantine Requirements

None.

B. Protection of Contacts of a Case

Discard any suspect foods.

C. Managing Special Situations

Reported Incidence Is Higher than Usual/Outbreak Suspected

If the number of reported cases of listeriosis in the LPHA’s jurisdiction is higher than usual, or if an outbreak is suspected, consult with an epidemiologist at CADE at (800) 362-2736.  Investigate to determine the source of infection and mode of transmission. A common vehicle, such as food, should be sought and applicable preventive or control measures should be instituted. CADE can help determine a course of action to prevent further cases and can perform surveillance for cases across county lines and therefore be difficult to identify at a local level.

Note: Refer to IDPH’s Foodborne Manual for comprehensive information on investigating foodborne illness complaints and outbreaks.

Multi-State Clusters

The Centers for Disease Control and Prevention (CDC) is working to identify and analyze multi-state clusters of listeriosis. Cases that may be part of such clusters will require additional follow-up and data collection from the local public health agency. CADE will provide directions on follow-up activities for such situations on a case-by-case basis.

D. Preventive Measures

Environmental Measures

Implicated food items must be removed from the environment. A decision about testing implicated food items can be made in consultation with CADE. CADE can help coordinate pickup and testing of food samples. If a commercial product is suspected, CADE will coordinate follow-up with relevant outside agencies.

Note: Refer to Iowa’s Foodborne Illness Outbreak Investigation Manual for comprehensive information in investigating foodborne illness complaints and outbreak.

Personal Preventive Measures/Education

General recommendations:

  • Thoroughly cook raw food from animal sources, such as beef, pork, or poultry.

  • Wash raw vegetables thoroughly before eating.
  • Keep uncooked meats separate from vegetables and from cooked foods and ready-to-eat foods.
  • Avoid unpasteurized (raw) milk or foods made from unpasteurized milk.
  • Wash hands, knives, and cutting boards after handling uncooked foods.
  • Consume perishable and ready-to-eat foods as soon as possible.

Recommendations for persons at high risk, such as pregnant women and persons with weakened immune systems, in addition to the recommendations listed above:

  • Do not eat hot dogs, luncheon meats, or deli meats, unless they are reheated until steaming hot.
  • Avoid getting fluid from hot dog packages on other foods, utensils, and food preparation surfaces, and wash hands after handling hot dogs, luncheon meats, and deli meats.
  • Do not eat soft cheeses such as feta, Brie, and Camembert, blue-veined cheeses, or Mexican-style cheeses such as queso blanco, queso fresco, and Panela, unless they have labels that clearly state they are made from pasteurized milk.
  • Do not eat refrigerated pâtés or meat spreads. Canned or shelf-stable pâtés and meat spreads may be eaten.
  • Do not eat refrigerated smoked seafood, unless it is contained in a cooked dish, such as a casserole. Refrigerated smoked seafood, such as salmon, trout, whitefish, cod, tuna or mackerel, is most often labeled as "nova-style," "lox," "kippered," "smoked," or "jerky." The fish is found in the refrigerator section or sold at deli counters of grocery stores and delicatessens. Canned or shelf-stable smoked seafood may be eaten.

Iowa Dept. of Public Health, Reviewed 7/15