Food > Consumer Centre > Causes of Food Borne Illness 

Shigella Food Safety Facts
Preventing foodborne illness

What is foodborne illness?

Food contaminated by bacteria, viruses and parasites can make you sick. Many people have had foodborne illness and not even known it. It’s sometimes called food poisoning, and it can feel like the flu. Symptoms may include the following:

• stomach cramps
• nausea
• vomiting
• diarrhea
• fever

Symptoms can start soon after eating contaminated food, but they can hit up to a month or more later. For some people, especially young children, the elderly, pregnant women and people with weakened immune systems, foodborne illness can be very dangerous.

Public health experts estimate that there are 11 to 13 million cases of foodborne illness in Canada every year. Most cases of foodborne illness can be prevented by using safe food handling practices and using a food thermometer to check that your food is cooked to a safe internal temperature!

What are Shigella and shigellosis?

Shigella bacteria are found naturally in the intestinal tracts of humans and other primates. People who eat food or drink water contaminated by Shigella can become ill with shigellosis.

What are the symptoms of shigellosis infection?

Like other foodborne illnesses, the symptoms of shigellosis can feel like the flu. Symptoms can appear within 12 to 50 hours after eating contaminated food, but usually don’t appear until three to seven days later. People who have shigellosis are usually ill for three to 14 days. Others infected with the bacteria may not get sick or show symptoms, but they can carry the bacteria and spread the infection to others.

How do the bacteria spread?

Shigellosis is most often spread from person-to-person. Shigella can also be transferred by flies. People infected with the bacteria can be carriers. Therefore, proper hygiene, safe food handling and preparation practices are key to preventing foodborne illness. If you think you are infected with Shigella or any other gastrointestinal illness, do not prepare food for other people unless you wear disposable gloves and follow safe food handling procedures. About 20 per cent of shigellosis infections come directly from contaminated food and water.

Where has Shigella been found?

Food is most commonly contaminated with Shigella from water polluted by human sewage. Food can also become contaminated if it is handled by a person infected with Shigella or by cross-contamination because of unsanitary food handling practices. The following listed below have been responsible for foodborne illnesses:

• salads (pasta, potato, shrimp, tuna, chicken, turkey, macaroni, fruit, lettuce)
• chopped turkey
• rice balls
• beans
• pudding
• produce such as strawberries, spinach, fresh daikon (a type of radish)
• raw oysters
• deli meats
• unpasteurized milk

Will cooking destroy the bacteria?

Like many other harmful bacteria that could be in our food, Shigella are destroyed when food is cooked to a safe internal temperature. Use a food thermometer to measure the internal temperature of your food. See table.

Defeating Shigella Bacteria: A 4-Point Plan

1. Get off to a CLEAN start!
   • Handwashing is one of the best ways to prevent the spread of foodborne illness. Do you wash your hands for at least 20 seconds with soap and warm water before and after handling food? Wash again when you switch from one food to another.
   • Are your countertops and utensils clean and sanitized? Sanitizing reduces bacteria and can prevent foodborne illness.

   BLEACH SANITIZER Combine 5 mL (1 tsp) of bleach with 750 mL (3 cups) of water in a labelled spray bottle. After cleaning, spray sanitizer on the surface/utensil and let stand briefly. Rinse with lots of clean water, and air dry (or use clean towels).

   Foodsafe tip: Use only clean water to water vegetable/fruit/herb gardens. Shigella bacteria can live in contaminated water and might contaminate the food you eat.

2. CHILL your food and stop bacteria cold!
   • Bacteria can grow in the danger zone between 4 °C and 60 °C (40°F to 140°F). Keep cold food cold at or below 4 °C (40°F).
   • Refrigeration at or below 4°C (40 F) slows down most bacterial growth. Freezing at or below -18°C (0°F) can stop it completely. (But remember: chilling won’t kill bacteria. Only proper cooking will do that!)

   Foodsafe tip: Use appliance thermometers to check that your refrigerator and freezer are cold enough.

3. SEPARATE! Don’t cross-contaminate!
   • Keep raw foods away from other foods while shopping, storing and preparing foods.

   Foodsafe tip: When shopping, place raw meat in a plastic bag, then place it in your shopping cart away from other foods.

4. COOK safely!
   • Have you cooked your food to a safe internal temperature? Use a digital food thermometer to check the temperature of your food. See table.
   • Bacteria can grow quickly in the danger zone between 4 °C and 60°C (40 °F to 140 °F), so keep hot food at or above 60°C (140 °F).

   Foodsafe tip: The only way to be sure that your food is cooked properly is to use a food thermometer to check.

Safeguarding Canada's Food Supply

The Canadian Food Inspection Agency (CFIA) is the Government of Canada’s science-based regulator for animal health, plant protection and, in partnership with Health Canada, food safety.

For more information on food safety or to order free copies of this brochure, visit the CFIA website at www.inspection.gc.ca or call 1 800 442-2342/TTY 1 800 465-7735 (8:00 a.m. to 8:00 p.m. Eastern Standard Time, Monday to Friday). You can also find food safety information on the Health Canada and Canadian Partnership for Consumer Food Safety Education websites respectively at www.hc-sc.gc.ca and www.canfightbac.org.

Cat. no.: A104-16/2005E
ISBN: 0-662-41100-5
P0238E-05/06