Microbiology - Foodborne Illness
Food samples are examined for the presence of disease-producing bacteria only in cases of documented illness involving at least two persons. Foods suspected of adulteration or those not associated with illness are referred to the Food and Drug Administration through the N.C. Department of Agriculture. Food samples are accepted only when submitted through the local health department. The local health department should always be notified of suspected foodborne illness so that an epidemiological investigation can be conducted. Feces and other specimens relating to foodborne disease also are accepted. The Microbiology Unit should be alerted at (919) 733-7367 as soon as possible after illness is reported. Contact the Epidemiology and Communicable Disease Section at (919)733-3419 for assistance in investigating foodborne disease.
Each food item should be clearly labeled; different batches should be individually identified. Environmental samples should be labeled as to individual source. Fecal or other specimens should be clearly labeled with the patient´s name; requisition forms should indicate their association with foodborne illness.
- Food and Related Environmental Samples
Collect food samples aseptically taking care not to touch the food items with the hands or non-sterile equipment. Samples should be placed in sterilized jars or sealable plastic bags and promptly refrigerated. Packaging and shipping methods should maintain the integrity of the food sample as closely as possible to its condition when sampled. Use a separate DHHS form #1814 for each food item; when submitting multiple samples at least one form should be completed with all requested information.
If botulism is suspected immediately contact the Epidemiology and Communicable Disease Section at (919) 733-3419.
- Food Handlers
To culture potential carriers of Staphylococcus, carefully rub sterile swab over infected area, avoiding contact with adjacent skin, or swab anterior nasal membranes. Use DHHS form 4121, Special Bacteriology.
- Fecal Specimens
See Enteric Bacteriology, for instructions for collecting specimens for bacteriological culture. See Virus Culture, for collecting specimens for viral culture.
Food samples should be placed in a waterproof container inside an insulated shipping container with cold packs (do not use wet ice) and sent to the SLPH as quickly as possible after collection. Notify the Microbiology Unit of the expected arrival time. Outbreak-associated fecal specimens may be shipped separately in Enteric Culture Mailers.
Reporting Procedure and Interpretation
Bacteriological examination of food requires one to seven work days, depending on the etiologic agent and the type of food processing involved. Foods are implicated as vehicles of disease transmission under one or more of the following circumstances:
- confirmation of the same pathogen or toxin in ill patients´ specimens and in the epidemiologically implicated food
- confirmation of the presence of bacterial toxin in the food in the absence of patient clinical specimens
- confirmation of the presence of certain enteric pathogens such as Salmonella in the food
- food-specific attack rates significantly higher in persons who have consumed the food compared to those who have not
Note: Local health departments should notify the Epidemiology and Communicable Disease Section (919) 733-3419 when enteric disease outbreaks are suspected in a daycare center, nursing home or restaurant. Additionally, the Food, Lodging and Institutional Sanitation Branch of the Division of Environmental Health should be notified at (919) 707-5854 when foodborne illness is suspected in a restaurant or institution.
- About Microbiology
- Bordetella Pertussis
- Enteric Bacteriology
- Foodborne Illness
- Neisseria Gonorrhoeae
- Special & Atypical Bacteriology
- Turnaround Times