HIC Foodborne Illness Investigation 3 — Questions and Answers
Question 1: When collecting environmental swab samples during a foodborne illness investigation, which surface should be prioritized?
- Food-contact surfaces such as cutting boards, slicers, and prep tables (Correct answer)
- Walls and ceilings of the dining area
- Exterior door handles and window sills
- Employee restroom mirrors and light switches
Correct answer: Food-contact surfaces such as cutting boards, slicers, and prep tables
Food-contact surfaces are the highest priority for environmental swabbing because contamination there directly transfers to food products.
Question 2: A health inspector discovers that leftover soup was cooled by being placed directly into a walk-in cooler in a deep, covered stock pot. What is the primary concern?
- The soup's mass and insulation will prevent it from cooling through the danger zone quickly enough (Correct answer)
- The walk-in cooler will become too cold for other stored products
- The pot lid will cause excessive condensation on shelves
- The soup color will change due to rapid temperature fluctuation
Correct answer: The soup's mass and insulation will prevent it from cooling through the danger zone quickly enough
Cooling large volumes of soup in a deep, covered pot traps heat, causing the food to remain in the temperature danger zone (41–135°F) longer than the required 2-hour and 6-hour cooling parameters.
Question 3: Which foodborne pathogen is most commonly associated with ready-to-eat deli meats and soft cheeses and can grow at refrigeration temperatures?
- Listeria monocytogenes (Correct answer)
- Clostridium botulinum
- Campylobacter jejuni
- Cryptosporidium parvum
Correct answer: Listeria monocytogenes
Listeria monocytogenes is unique among major foodborne pathogens because it can multiply at refrigerator temperatures (as low as 34°F/1°C), making it especially dangerous in RTE deli products.
Question 4: Under FDA Food Code guidelines, what is the correct cooling procedure for a large batch of cooked chicken?
- Cool from 135°F to 70°F within 2 hours, then from 70°F to 41°F within an additional 4 hours (Correct answer)
- Cool from 165°F to 41°F within 4 hours total
- Cool from 140°F to 41°F within 6 hours without interim checkpoints
- Cool from 135°F to 41°F within 2 hours using any method
Correct answer: Cool from 135°F to 70°F within 2 hours, then from 70°F to 41°F within an additional 4 hours
The FDA Food Code two-stage cooling requirement mandates 135°F→70°F in 2 hours and 70°F→41°F in 4 more hours (6 hours total) to minimize pathogen growth.
Question 5: During an investigation, a food worker reports vomiting and diarrhea that started 2 hours after eating at the same event. Which toxin-mediated illness best matches this rapid onset?
- Staphylococcus aureus intoxication (Correct answer)
- Salmonellosis
- Hepatitis A infection
- Listeriosis
Correct answer: Staphylococcus aureus intoxication
S. aureus produces preformed heat-stable enterotoxins that cause vomiting and diarrhea within 1–6 hours, far faster than infections requiring bacterial colonization.
Question 6: What does a 'traceback investigation' accomplish in a foodborne illness outbreak?
- It follows the contaminated food product backwards through the supply chain to identify its origin (Correct answer)
- It tracks the movement of ill individuals after they left the establishment
- It measures how far pathogens spread through the air in the kitchen
- It calculates the time elapsed since the establishment's last inspection
Correct answer: It follows the contaminated food product backwards through the supply chain to identify its origin
A traceback investigation moves upstream through distribution, processing, and production records to find the original source of a contaminated food product.
Question 7: Which document should a health inspector request first when investigating a possible outbreak at a catered event?
- The event menu and food preparation records, including invoices for all ingredients (Correct answer)
- The establishment's last routine inspection report
- The catering company's profit and loss statement
- The names of all guests who attended the event
Correct answer: The event menu and food preparation records, including invoices for all ingredients
Menu and preparation records with invoices reveal every food served and its source, forming the foundation for hypothesis generation and traceback.
HIC Foodborne Illness Investigation 3
When collecting environmental swab samples during a foodborne illness investigation, which surface should be prioritized?