I85PREP
⌘ K
CP-FS study materials
CP-FS study resources

CP-FS practice questions

One question at a time. Build your CP-FS understanding.

First 50 of 200 questions. Each one lists the choices, the correct answer, and an explanation. The checker at the top of this page saves progress in this browser when it is available.

Continue in the practice tool above to load more questions, 50 at a time.

Question 1Food Safety Management Systems (HACCP and Preventive Controls)

How many principles make up the HACCP system as defined by Codex Alimentarius?

  1. Seven principles Correct answer.
  2. Nine principles
  3. Four principles
  4. Five principles

Explanation

Codex HACCP consists of seven principles that begin with hazard analysis and end with recordkeeping procedures. They are applied after preliminary steps such as assembling the team and describing the product.

Question 2Food Safety Management Systems (HACCP and Preventive Controls)

Before applying the seven HACCP principles, which task should be completed first?

  1. Conduct a hazard analysis
  2. Determine critical control points
  3. Assemble a HACCP team Correct answer.
  4. Establish verification procedures

Explanation

Preliminary steps include assembling a multidisciplinary HACCP team, describing the product and its use, constructing a flow diagram, and verifying the diagram on site. Hazard analysis and CCP determination are principles applied after those preliminary tasks.

Question 3Food Safety Management Systems (HACCP and Preventive Controls)

In a HACCP plan, a critical limit is best described as:

  1. A target for product quality attributes
  2. The average temperature of the processing room
  3. A value separating acceptable from unacceptable Correct answer.
  4. A value that triggers a customer complaint

Explanation

A critical limit is a measurable criterion that must be met to prevent, eliminate, or reduce a significant hazard to an acceptable level. It defines the boundary between safe and unsafe operation at a CCP.

Question 4Food Safety Management Systems (HACCP and Preventive Controls)

What is the primary purpose of monitoring a critical control point?

  1. To validate the hazard analysis
  2. To show the CCP stays within its critical limits Correct answer.
  3. To document employee training
  4. To satisfy customer audit requirements

Explanation

Monitoring is a planned sequence of observations or measurements that shows whether a CCP is operating within its critical limits. It provides the evidence needed to take timely corrective action when control is lost.

Question 5Food Safety Management Systems (HACCP and Preventive Controls)

When a CCP deviation occurs, a corrective action must include:

  1. Only a phone call to the customer
  2. Only recalibration of the instrument
  3. Only a note in the production log
  4. Product disposition and correction of the cause Correct answer.

Explanation

Corrective actions must address both the affected product, such as holding and evaluating it, and the cause of the deviation. The action and its outcome are then recorded.

Question 6Food Safety Management Systems (HACCP and Preventive Controls)

Which statement best distinguishes verification from validation?

  1. Verification is performed only by regulators
  2. Verification confirms the plan works as intended Correct answer.
  3. Verification replaces CCP monitoring
  4. Verification proves the plan is scientifically sound before use

Explanation

Validation is done before implementation to show that the control measures can control the hazard. Verification is ongoing and confirms that the plan is being followed and is working as intended.

Question 7Food Safety Management Systems (HACCP and Preventive Controls)

After a flow diagram is prepared, what should the HACCP team do?

  1. Post it in the customer service area
  2. Use it only for new-hire orientation
  3. File it without any further review by the team
  4. Verify it on site against actual operations Correct answer.

Explanation

The HACCP team must verify the accuracy of the flow diagram by walking the process on site. This confirms that every step, input, and rework loop is represented before hazard analysis proceeds.

Question 8Food Safety Management Systems (HACCP and Preventive Controls)

Which of the following is an example of a prerequisite program rather than a HACCP principle?

  1. Pest control Correct answer.
  2. Critical limit setting
  3. Hazard analysis
  4. CCP monitoring

Explanation

Prerequisite programs provide the basic environmental and operational conditions needed for food safety, such as pest control, sanitation, and employee hygiene. HACCP principles address hazard analysis, CCPs, limits, monitoring, corrective actions, verification, and records.

Question 9Food Safety Management Systems (HACCP and Preventive Controls)

A processor of ready-to-eat deli salads identifies Listeria monocytogenes as a significant hazard. Which control is most appropriate?

  1. Environmental monitoring plus sanitation controls Correct answer.
  2. Cooking instructions on the label
  3. Finished product testing used as the only control
  4. A supplier audit program alone

Explanation

Ready-to-eat foods that support Listeria growth require controls aimed at the processing environment, including sanitation and environmental monitoring. Finished product testing alone cannot reliably detect or prevent contamination.

Question 10Food Safety Management Systems (HACCP and Preventive Controls)

A packaged product passes through a metal detector as the last step before casing. When is this step a CCP?

  1. When metal is a significant hazard and no later step removes it Correct answer.
  2. Only if the detector is calibrated annually
  3. Only when a customer specifically requests it
  4. Never, because packaging is not considered a food safety step

Explanation

A step becomes a CCP when it is the point where control can be applied to a significant hazard and no later step will remove or reduce that hazard. Metal detection after packaging can therefore be a CCP if metal is a significant hazard.

Question 11Food Safety Management Systems (HACCP and Preventive Controls)

A critical limit for cooking poultry is set at 165°F internal temperature. What is the best basis for this limit?

  1. Scientific validation such as pathogen lethality studies Correct answer.
  2. A marketing claim
  3. A competitor's published HACCP plan copied without review
  4. Employee preference

Explanation

Critical limits must be supported by scientific evidence or regulatory standards showing the process achieves the needed reduction of the target pathogen. Validation documents that the chosen limit is capable of controlling the hazard.

Question 12Food Safety Management Systems (HACCP and Preventive Controls)

At what frequency should CCP monitoring be conducted?

  1. Only when a deviation occurs
  2. Continuously or often enough to show control Correct answer.
  3. At the end of each production run
  4. Once per year during the third-party audit

Explanation

Monitoring must be frequent enough to detect loss of control before product is affected, and continuous monitoring is used where feasible. The chosen frequency is justified in the HACCP plan.

Question 13Food Safety Management Systems (HACCP and Preventive Controls)

Monitoring at a CCP shows the critical limit was exceeded. What should be done first?

  1. Restart the line without further review
  2. Ship the product and document the event later
  3. Place affected product on hold and evaluate it Correct answer.
  4. Recalibrate the instrument and release the lot

Explanation

Product produced during a deviation must be held and evaluated for safety before any disposition decision. Corrective action procedures also require addressing the cause and recording the actions taken.

Question 14Food Safety Management Systems (HACCP and Preventive Controls)

Which activity is an example of verification?

  1. Writing the hazard analysis
  2. Reviewing monitoring records and calibration logs Correct answer.
  3. Checking the oven temperature every hour during production
  4. Setting a critical limit for a CCP

Explanation

Verification includes activities such as record review, calibration checks, and audits that confirm the HACCP plan is being implemented and is effective. Hourly temperature checks are monitoring, while setting limits and writing the hazard analysis are plan development.

Question 15Food Safety Management Systems (HACCP and Preventive Controls)

Which activity is an example of validation?

  1. Conducting a challenge study to confirm a kill step Correct answer.
  2. Reviewing daily CCP monitoring logs with the supervisor
  3. Training new employees
  4. Calibrating thermometers

Explanation

Validation provides scientific evidence that a control measure can achieve the intended hazard reduction, such as a challenge study for a kill step. Record review, calibration, and training are verification or prerequisite activities.

Question 16Food Safety Management Systems (HACCP and Preventive Controls)

Which practice best controls allergen cross-contact between runs?

  1. Schedule allergen runs last with no cleaning
  2. Use dedicated utensils and verify changeover cleaning Correct answer.
  3. Store allergens in unlabeled containers next to the production line
  4. Rely on supplier certificates only

Explanation

Allergen control requires segregation, dedicated equipment where feasible, and verified cleaning between allergen-containing and allergen-free runs. Supplier certificates and scheduling alone do not prevent cross-contact on shared equipment.

Question 17Food Safety Management Systems (HACCP and Preventive Controls)

Under a supply-chain program, what should a receiving facility do for a hazard requiring a supplier control?

  1. Test every incoming lot for every hazard
  2. Buy from the lowest-cost supplier
  3. Approve and verify suppliers control hazards Correct answer.
  4. Require a product brochure from each supplier

Explanation

The supply-chain program requires approval of suppliers and verification that they are controlling the identified hazards, through audits, records, or other appropriate means. Cost and brochures are not verification of hazard control.

Question 18Food Safety Management Systems (HACCP and Preventive Controls)

Which practice is part of an environmental monitoring program for an RTE facility?

  1. Swabbing food contact surfaces for Listeria indicators Correct answer.
  2. Measuring freezer temperature
  3. Testing finished product lots for pathogens after release
  4. Checking pest control logs

Explanation

Environmental monitoring samples surfaces in the processing environment to detect pathogen indicators or harborage, especially for Listeria in RTE operations. Finished product testing, temperature measurement, and pest logs serve other purposes.

Question 19Food Safety Management Systems (HACCP and Preventive Controls)

What should a food facility have in place before a recall becomes necessary?

  1. Reliance on FDA to manage the recall
  2. Recall plans only for wholesale distributors
  3. Verbal instructions to be given during a crisis
  4. A written recall plan with mock recall exercises Correct answer.

Explanation

A written recall plan identifies roles, contact information, and procedures for tracing and retrieving product, and it should be tested through mock recalls. Planning in advance allows faster and more effective removal of product from the market.

Question 20Food Safety Management Systems (HACCP and Preventive Controls)

How does HARPC differ from traditional HACCP?

  1. HACCP always requires environmental monitoring
  2. HARPC eliminates the need for prerequisite programs
  3. HARPC covers radiological and allergen hazards Correct answer.
  4. HARPC applies only to meat and poultry slaughter operations

Explanation

HARPC, the preventive controls approach under FSMA, requires hazard analysis that includes chemical, physical, biological, radiological, and allergen hazards. Traditional HACCP frameworks often focus more narrowly on significant hazards at CCPs.

Question 21Food Safety Management Systems (HACCP and Preventive Controls)

Which event most clearly requires a reanalysis of the HACCP or food safety plan?

  1. A supplier changes its regular delivery day without notice
  2. A new production employee is hired and trained
  3. A new pathogen hazard is identified in the process Correct answer.
  4. Monthly record review is completed

Explanation

Reanalysis is required when there is a significant change that could affect hazard analysis or control measures, such as a newly identified pathogen hazard. Routine staffing, delivery timing, and record review do not by themselves require reanalysis.

Question 22Food Safety Management Systems (HACCP and Preventive Controls)

Which statement about process preventive controls is accurate?

  1. Sanitation controls are never considered preventive controls
  2. Process controls apply only to physical hazards
  3. Sanitation controls can replace all CCPs in a plan
  4. A kill step is a process preventive control Correct answer.

Explanation

Process preventive controls are procedures applied at a specific step to control a hazard, such as a thermal kill step or a metal detection step. Sanitation controls are a separate category of preventive controls and do not replace the need for process controls where a kill step is required.

Question 23Food Safety Management Systems (HACCP and Preventive Controls)

An RTE plant finds Listeria on a non-food-contact surface. What is the most appropriate response?

  1. Take no action because the surface is non-contact
  2. Recall all product immediately
  3. Investigate and intensify sanitation controls Correct answer.
  4. Wait for finished product results only

Explanation

A positive environmental result on a non-food-contact surface indicates possible harborage or sanitation weakness and requires investigation, intensified cleaning and sanitizing, and assessment of adjacent food-contact surfaces. Immediate recall is not automatic without evidence of product contamination.

Question 24Food Safety Management Systems (HACCP and Preventive Controls)

At what point should CCP monitoring records be reviewed?

  1. Only during the annual third-party audit
  2. Only when a deviation is found
  3. Once every five years
  4. At a set frequency before release Correct answer.

Explanation

Monitoring records should be reviewed at a defined frequency established in the plan, often before product release, to confirm critical limits were met. This record review is part of verification and allows corrective action before affected product is distributed.

Question 25Food Safety Management Systems (HACCP and Preventive Controls)

Which hazard is most likely to require a preventive control in a ready-to-eat food?

  1. Product weight shortfall against the label
  2. Color variation among baked goods in a batch
  3. Listeria on a food-contact surface Correct answer.
  4. Aesthetic blemishes on the skin of produce

Explanation

Listeria on a food-contact surface is a biological hazard that can contaminate ready-to-eat food and cause illness without a further kill step. Aesthetic defects, color variation, and weight shortfalls are quality or labeling issues unless they create a specific safety hazard.

Question 26Foodborne Illness, Epidemiology, and Risk Assessment

Norovirus is the leading cause of foodborne illness outbreaks in the United States. Which feature of the virus best explains how a single infected food worker can contaminate enough food to make dozens of customers ill?

  1. It forms heat-resistant spores
  2. It has a very low infectious dose Correct answer.
  3. It multiplies only in anaerobic conditions
  4. It produces a preformed toxin in food

Explanation

Norovirus has an infectious dose of roughly 10 to 100 virus particles, so even microscopic contamination transferred from hands to ready-to-eat food can infect many people. It does not form spores, does not produce a preformed toxin, and is not an anaerobe.

Question 27Foodborne Illness, Epidemiology, and Risk Assessment

The temperature range in which foodborne bacteria multiply most rapidly is approximately:

  1. Below 0°F
  2. 135°F to 165°F
  3. 0°F to 41°F
  4. 41°F to 135°F Correct answer.

Explanation

The temperature danger zone is 41°F to 135°F (5°C to 57°C), where bacterial generation times are shortest. Foods should be held outside this range, either cold at 41°F or below or hot at 135°F or above.

Question 28Foodborne Illness, Epidemiology, and Risk Assessment

Which pathogen is of greatest concern in refrigerated ready-to-eat foods such as deli salads and smoked fish because it can continue to multiply at refrigerator temperatures?

  1. Salmonella enterica
  2. Staphylococcus aureus
  3. Listeria monocytogenes Correct answer.
  4. Campylobacter jejuni

Explanation

Listeria monocytogenes is psychrotrophic, meaning it can grow at normal refrigeration temperatures, so long refrigerated storage of ready-to-eat foods increases risk. It is also relatively salt- and acid-tolerant compared with many other pathogens.

Question 29Foodborne Illness, Epidemiology, and Risk Assessment

Hemolytic uremic syndrome, a leading cause of acute kidney failure in children, is most closely associated with which organism?

  1. Vibrio parahaemolyticus
  2. Clostridium perfringens
  3. Bacillus cereus
  4. Shiga toxin-producing Escherichia coli Correct answer.

Explanation

Shiga toxin-producing E. coli, classically serotype O157:H7, releases Shiga toxins that damage renal endothelial cells and can produce hemolytic uremic syndrome. Undercooked ground beef, raw milk, and contaminated produce are common vehicles.

Question 30Foodborne Illness, Epidemiology, and Risk Assessment

Which set of conditions is required for Clostridium botulinum to grow and produce toxin in a food?

  1. Aerobic conditions in a high-acid food
  2. Storage at freezer temperatures
  3. Anaerobic conditions in a low-acid food Correct answer.
  4. A dry environment with low water activity

Explanation

Clostridium botulinum is an anaerobic spore former that produces toxin only in moist, low-acid foods (pH above about 4.6) that are free of oxygen. This is why low-acid canned foods receive a botulinum cook and why home-canned vegetables are a classic vehicle.

Question 31Foodborne Illness, Epidemiology, and Risk Assessment

A food worker with an infected cut on the hand contaminates a baked ham that is then left at room temperature for several hours. Which organism is most likely to cause illness through a preformed toxin?

  1. Listeria monocytogenes
  2. Hepatitis A virus
  3. Clostridium botulinum
  4. Staphylococcus aureus Correct answer.

Explanation

Staphylococcus aureus is carried on skin and in infected wounds and produces heat-stable enterotoxins in protein-rich foods held in the danger zone. Illness follows ingestion of the preformed toxin, typically within 1 to 6 hours.

Question 32Foodborne Illness, Epidemiology, and Risk Assessment

Which foodborne agent is a virus transmitted by the fecal-oral route that causes jaundice and has an incubation period of roughly 28 days?

  1. Cyclospora cayetanensis
  2. Hepatitis A virus Correct answer.
  3. Norovirus
  4. Campylobacter jejuni

Explanation

Hepatitis A virus is spread by the fecal-oral route, often by infected food workers, and produces an illness with an average incubation of about 28 days that frequently includes jaundice. Norovirus has a much shorter incubation of 12 to 48 hours.

Question 33Foodborne Illness, Epidemiology, and Risk Assessment

Scombroid poisoning follows eating tuna or mackerel that has been temperature abused. Which statement about the causative agent is correct?

  1. It is produced by Clostridium botulinum
  2. It is a heat-stable histamine formed by bacterial decarboxylation Correct answer.
  3. It is a virus that infects the intestinal lining
  4. It is destroyed by thorough cooking

Explanation

Bacteria such as Morganella morganii decarboxylate histidine in dark-fleshed fish to histamine when the fish is not rapidly chilled. The toxin is heat-stable, so cooking does not prevent illness, and symptoms resemble an allergic reaction.

Question 34Foodborne Illness, Epidemiology, and Risk Assessment

At a catered banquet, 60 of the 150 people who ate the chicken entree became ill, while 5 of the 50 people who did not eat the chicken became ill. What is the attack rate among those who ate the chicken?

  1. 10%
  2. 40% Correct answer.
  3. 60%
  4. 12%

Explanation

The attack rate is the number of cases among exposed persons divided by the total number exposed: 60 ÷ 150 = 0.40, or 40%. The attack rate among those who did not eat the chicken is 5 ÷ 50 = 10%, and comparing the two helps identify the vehicle.

Question 35Foodborne Illness, Epidemiology, and Risk Assessment

Which measure describes the proportion of persons diagnosed with a disease who die from it within a specified period?

  1. Case fatality rate Correct answer.
  2. Prevalence
  3. Incidence rate
  4. Attack rate

Explanation

The case fatality rate divides deaths from a disease by the number of diagnosed cases over the same period, expressing severity. Incidence describes new cases in a population at risk, while prevalence describes all existing cases at a point in time.

Question 36Foodborne Illness, Epidemiology, and Risk Assessment

An epidemic curve shows a single sharp peak occurring within a few hours of a banquet, followed by a rapid decline and no later secondary peaks. This pattern most strongly suggests:

  1. An outbreak spread by an insect vector
  2. A continuous common-source exposure
  3. A point-source exposure Correct answer.
  4. A propagated person-to-person outbreak

Explanation

A single abrupt peak whose width approximates the incubation period, with no subsequent waves, is the classic signature of a point-source exposure such as a single meal. Continuous exposure produces a plateau, and person-to-person spread produces successive progressively spaced peaks.

Question 37Foodborne Illness, Epidemiology, and Risk Assessment

Illness with vomiting beginning 1 to 5 hours after eating cooked rice that was held at room temperature is most likely caused by:

  1. Campylobacter jejuni
  2. Clostridium perfringens
  3. Salmonella enterica serotype Enteritidis
  4. Bacillus cereus, emetic toxin type Correct answer.

Explanation

Bacillus cereus produces a heat-stable emetic toxin (cereulide) in cooked rice left at room temperature, causing vomiting within 1 to 6 hours. The diarrheal type of B. cereus illness has a longer incubation of 8 to 16 hours and is associated with meats and sauces.

Question 38Foodborne Illness, Epidemiology, and Risk Assessment

Which of the four components of microbiological risk assessment estimates the likelihood and severity of illness in a population by integrating the other three components?

  1. Hazard identification
  2. Risk characterization Correct answer.
  3. Exposure assessment
  4. Dose-response assessment

Explanation

Risk characterization is the final step of risk assessment, combining hazard identification, exposure assessment, and dose-response information to estimate risk and its uncertainty. It produces the estimate that risk managers use to select control measures.

Question 39Foodborne Illness, Epidemiology, and Risk Assessment

A church supper roast beef held for several hours at 120°F causes watery diarrhea about 10 hours later in many attendees, with little or no vomiting. Which organism best fits this picture?

  1. Clostridium perfringens Correct answer.
  2. Staphylococcus aureus
  3. Hepatitis A virus
  4. Bacillus cereus, emetic type

Explanation

Clostridium perfringens spores survive cooking, and when meat is held in the danger zone the vegetative cells multiply to high numbers; ingestion followed by sporulation in the intestine produces diarrhea after roughly 8 to 24 hours without prominent vomiting. Gravies, stews, and rolled meats are typical vehicles.

Question 40Foodborne Illness, Epidemiology, and Risk Assessment

In epidemiology, the living organism in which a pathogen normally lives and multiplies is called the:

  1. Carrier
  2. Vehicle
  3. Vector
  4. Reservoir Correct answer.

Explanation

A reservoir is the natural habitat where a pathogen persists and multiplies, such as humans, animals, soil, or water. A vehicle is the inanimate object or food that transmits the agent, a vector is an arthropod transmitter, and a carrier is an infected individual who sheds the agent.

Question 41Foodborne Illness, Epidemiology, and Risk Assessment

Which organism is the most commonly reported bacterial cause of diarrheal illness in many countries and is strongly associated with raw or undercooked poultry?

  1. Listeria monocytogenes
  2. Yersinia pestis
  3. Campylobacter jejuni Correct answer.
  4. Vibrio cholerae

Explanation

Campylobacter jejuni colonizes the intestinal tracts of poultry and contaminates meat during processing, making it one of the leading bacterial causes of gastroenteritis worldwide. It has also been linked to reactive arthritis and Guillain-Barré syndrome.

Question 42Foodborne Illness, Epidemiology, and Risk Assessment

Which pathogen causes severe, often fatal septicemia in persons with chronic liver disease who eat raw oysters harvested from warm coastal waters?

  1. Trichinella spiralis
  2. Vibrio vulnificus Correct answer.
  3. Brucella melitensis
  4. Shigella sonnei

Explanation

Vibrio vulnificus occurs naturally in warm estuarine waters and concentrates in filter-feeding oysters; in people with chronic liver disease or iron overload it can invade the bloodstream with a high case fatality rate. Post-harvest cooling and consumer warnings for high-risk persons are key controls.

Question 43Foodborne Illness, Epidemiology, and Risk Assessment

Aflatoxin, a mycotoxin associated with liver cancer, is produced by molds growing on which foods when they are stored warm and humid?

  1. Pasteurized milk and soft cheese
  2. Fresh berries and leafy greens
  3. Peanuts, corn, and tree nuts Correct answer.
  4. Canned low-acid vegetables

Explanation

Aspergillus flavus and related molds produce aflatoxins in oilseeds, peanuts, corn, and tree nuts when temperature and humidity favor mold growth. Control relies on rapid drying and dry storage of these commodities.

Question 44Foodborne Illness, Epidemiology, and Risk Assessment

Trichinellosis, acquired from undercooked pork or wild game, is best prevented by:

  1. Freezing all fresh produce before use
  2. Rinsing game meat with vinegar solution
  3. Cooking pork and game to a temperature that kills the larvae Correct answer.
  4. Adding nitrite to all cured sausages

Explanation

Trichinella larvae encysted in muscle are killed by adequate cooking, which for pork means reaching 145°F with a three-minute rest. Freezing can also inactivate some species, but cooking is the reliable control for pork and wild game.

Question 45Foodborne Illness, Epidemiology, and Risk Assessment

In food safety risk analysis, a hazard is best described as:

  1. The number of new cases in a population
  2. The amount of a substance a person ingests
  3. The probability that illness will result from a food
  4. An agent in food with the potential to cause harm Correct answer.

Explanation

A hazard is any biological, chemical, or physical agent in food with the potential to cause harm, whereas risk combines the likelihood and severity of that harm. Risk therefore depends on both the hazard and the exposure to it.

Question 46Foodborne Illness, Epidemiology, and Risk Assessment

In a quantitative microbial risk assessment, what does the dose-response assessment describe?

  1. The prevalence of the pathogen in the raw ingredient
  2. The survival of the pathogen during cooking
  3. The number of servings consumed per year
  4. The probability of illness at a given ingested dose Correct answer.

Explanation

The dose-response assessment models the relationship between the number of organisms ingested and the probability of illness, often using beta-Poisson or exponential models. It supplies the link between exposure estimates and predicted health outcomes in risk characterization.

Question 47Foodborne Illness, Epidemiology, and Risk Assessment

In an outbreak investigation, 70% of people who ate the potato salad became ill, compared with 10% of those who did not eat it. What is the relative risk (risk ratio)?

  1. 60
  2. 0.14
  3. 7.0 Correct answer.
  4. 6.0

Explanation

The risk ratio is the attack rate among the exposed divided by the attack rate among the unexposed: 0.70 ÷ 0.10 = 7.0. A value well above 1 indicates a strong association between the food and illness.

Question 48Foodborne Illness, Epidemiology, and Risk Assessment

A food worker who recovered from typhoid fever years ago still sheds Salmonella Typhi in stool and continues to handle food. This person is best described as:

  1. A fomite
  2. A vector
  3. A chronic carrier Correct answer.
  4. An index case

Explanation

A chronic carrier is a person who continues to harbor and shed a pathogen long after clinical recovery and can serve as a persistent source of contamination. Salmonella Typhi carriers are classically excluded from food handling because of this risk.

Question 49Foodborne Illness, Epidemiology, and Risk Assessment

A food contains 100 Salmonella cells and the generation time at room temperature is 30 minutes. Approximately how many cells will be present after 3 hours?

  1. 1,800
  2. 3,200
  3. 600
  4. 6,400 Correct answer.

Explanation

Three hours contains six 30-minute generations, so the population doubles six times: 100 × 2^6 = 6,400 cells. This exponential growth explains why short periods of temperature abuse can raise contamination to infectious levels.

Question 50Foodborne Illness, Epidemiology, and Risk Assessment

Which statement correctly distinguishes toxin-mediated foodborne illness from foodborne infection?

  1. Illness can occur soon after eating because no growth in the host is needed Correct answer.
  2. Illness requires the organism to multiply in the intestine first
  3. Illness cannot be traced to an infected food handler
  4. Illness is always caused by spore-forming bacteria

Explanation

In an intoxication such as staphylococcal or botulinal poisoning, the toxin is already present in the food, so the incubation period is short and no host colonization is required. In an infection, the organism must survive, colonize, and multiply in the host, which lengthens the incubation period.