Food Safety Foodborne Illness & Contamination Practice Questions
Foodborne Illness & Contamination makes up 8 of every 50 questions on a Tigertest Food Safety practice test. Here are 10 of the 32 questions on it, each with the answer and the reason.
Updated by the Tigertest team. Built on the FDA Food Code (2017 and 2022). Your local code may differ; check with your health department.
1. A server tells the manager her doctor has diagnosed her with typhoid fever. Which pathogen causes this illness?
- A.Shigella spp.
- B.Salmonella Typhi
- C.Norovirus
- D.Campylobacter jejuni
Answer: B. Typhoid fever is caused by Salmonella Typhi, which lives only in humans and can be shed long after symptoms end, so the server must be excluded and the regulatory authority notified. Campylobacter is a poultry-linked bacterium and is not one of the highly infectious pathogens that require exclusion.
2. An outbreak is traced to undercooked chicken and runny eggs served at a weekend brunch. Which pathogen is most commonly linked to these foods?
- A.Hepatitis A virus
- B.Bacillus cereus
- C.Vibrio vulnificus
- D.Nontyphoidal Salmonella
Answer: D. Nontyphoidal Salmonella is found in poultry, eggs, meat and dairy, and is controlled by cooking poultry to 165 F (74 C) and eggs to their required temperatures. Bacillus cereus is linked to cooked rice and starchy foods, not raw poultry and eggs.
3. Several guests become ill after eating a tossed salad made by a cook who skipped hand washing after using the restroom. Which bacterium is most likely?
- A.Shigella spp.
- B.Clostridium botulinum
- C.Bacillus cereus
- D.Vibrio parahaemolyticus
Answer: A. Shigella is carried in the feces of infected people and reaches ready-to-eat foods like salads through poor hand washing and flies, so hand washing and excluding sick workers are the controls. Clostridium botulinum is linked to improperly canned or low-oxygen foods, not to hand contact.
4. A guest develops bloody diarrhea and severe cramps after eating a rare hamburger. Which pathogen is most closely linked to undercooked ground beef?
- A.Anisakis simplex
- B.Staphylococcus aureus
- C.Shiga toxin-producing E. coli
- D.Hepatitis A virus
Answer: C. STEC such as E. coli O157:H7 lives in cattle intestines and is mixed through ground beef during grinding, so ground beef must reach 155 F (68 C) for 17 seconds. Staphylococcus aureus is linked to food handled after cooking, not to undercooked beef.
5. A prep cook at a seafood restaurant is diagnosed with hepatitis A. Which foods is this virus most often linked to in outbreaks?
- A.Cooked rice held at room temperature
- B.Large batches of cooled gravy
- C.Ready-to-eat foods and raw shellfish
- D.Home-canned low-acid vegetables
Answer: C. Hepatitis A spreads when infected workers touch ready-to-eat food and through shellfish from sewage-contaminated water, and cooking does not reliably destroy it. Home-canned vegetables are a botulism risk, not a hepatitis A risk.
6. Dozens of guests at a catered lunch develop sudden vomiting and diarrhea within a day after eating cold sandwiches. What is the most likely cause?
- A.Norovirus from a sick worker
- B.Clostridium perfringens from the deli meat
- C.Scombroid toxin in the meat
- D.Bacillus cereus in the lettuce
Answer: A. Norovirus is highly contagious, spreads from infected workers to ready-to-eat food, and is a leading cause of outbreaks with rapid vomiting and diarrhea. Clostridium perfringens is linked to large batches of cooked meat that were cooled too slowly, not to cold sandwiches.
7. Which pathogen is a special concern for pregnant women because it can grow in refrigerated deli meats and soft cheeses?
- A.Clostridium perfringens
- B.Shigella spp.
- C.Campylobacter jejuni
- D.Listeria monocytogenes
Answer: D. Listeria grows even at refrigeration temperatures, which is why ready-to-eat TCS food is date marked for no more than 7 days at 41 F (5 C) or below. Clostridium perfringens multiplies in cooked meat cooled too slowly, not in refrigerated deli products.
8. A cook makes a batch of garlic-in-oil and leaves it on a shelf at room temperature for several days. Which pathogen is the major hazard?
- A.Staphylococcus aureus
- B.Clostridium botulinum
- C.Vibrio parahaemolyticus
- D.Hepatitis A virus
Answer: B. Untreated garlic-in-oil is a TCS food because Clostridium botulinum grows without oxygen in low-acid conditions and makes a deadly toxin, so it must be held at 41 F or below or acidified. Staphylococcus aureus comes from hands and is not the main hazard of this low-oxygen mixture.
9. A caterer cooks a large stockpot of beef stew, lets it cool overnight on the counter, and serves it the next day. Which pathogen is most likely?
- A.Vibrio vulnificus
- B.Clostridium perfringens
- C.Shiga toxin-producing E. coli
- D.Hepatitis A virus
Answer: B. Clostridium perfringens spores survive cooking and multiply in large batches of meat, stew and gravy cooled too slowly, so food must cool from 135 F to 70 F within 2 hours and to 41 F within the next 4 hours. STEC is linked to undercooked ground beef, not to cooked stew that was cooled improperly.
10. A kitchen cooks rice in the morning and leaves it at room temperature until making fried rice at dinner. Which pathogen is the main concern?
- A.Campylobacter jejuni
- B.Hepatitis A virus
- C.Anisakis simplex
- D.Bacillus cereus
Answer: D. Bacillus cereus forms spores and toxins in cooked rice and other starchy foods left in the temperature danger zone, and stir-frying may not destroy its vomiting toxin. Campylobacter is mainly a poultry hazard.
Practice all 32 foodborne illness & contamination questions, and the rest of the 200-question bank, in the free Food Safety training sets. Questions you miss come back until you have mastered them.
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