3.3 Viruses, Parasites, and Fungi

Viruses do not grow in food

Viruses are not living cells in the FAT TOM sense. They have no lag phase in the potato salad and no log phase on the steam table. They hijack living human (or animal) cells to reproduce. On a CFPM exam that single fact rewrites the control plan. Holding coleslaw at 41°F stops Salmonella growth. It does not “starve” Norovirus that a sick prep cook already placed there with unwashed hands.

The two viruses that matter for this credential are the same two viruses on the Big Six list: Norovirus and Hepatitis A. Both are fecal-oral. Both hitchhike on ready-to-eat food — sandwiches, salads, garnishes, ice, utensils — and on shellfish harvested from sewage-contaminated water. A manager who only audits cook temperatures will miss both.

Norovirus is the volume problem: low infectious dose, violent vomiting, environmental persistence, and employees who come back to work too soon. Hepatitis A is the jaundice problem: a longer incubation, a more severe liver illness, and a reporting obligation the moment yellow eyes appear. Rotavirus appears in some public-health discussions of childhood diarrhea; it is not the CFPM Big Six pair and it should not crowd Norovirus and Hepatitis A off your list.

How viral contamination actually happens

Picture three kitchens.

In the first, a line cook uses the restroom, skips the 20-second handwash, and then tears lettuce for tacos. The lettuce is never cooked. The virus never needed to grow. That is the RTE pathway.

In the second, an oyster bar buys from a supplier that cannot show shellstock identification tags tied to approved waters. The oysters were filter-feeding in water contaminated with human sewage. Cooking may not be on the menu. That is the shellfish pathway.

In the third, a guest vomits in the dining room. A well-meaning server wipes the carpet with a sanitizer rag from the bar and then resets silverware. Norovirus particles aerosolize and settle on nearby food-contact surfaces. That is the environmental pathway, and it is why bodily-fluid cleanup is a written procedure, not a courtesy mop.

Virus prevention that actually works

Cooking is a supporting actor, not the lead. Some viruses are reduced by a full cook, but the foods they contaminate most often are never recooked. Do not tell yourself that a cold-holding log is a Norovirus program.

Parasites: water, produce, game, and raw fish

Parasites are living organisms that need a host. Like viruses, they do not use your steam table as a growth chamber. Like bacteria, some of them are destroyed by a complete cook. The CFPM list to carry is Cyclospora, Cryptosporidium, Giardia, Trichinella, and Anisakis. You will also see Toxoplasma in broader public-health material; the five above are the ones that map cleanly onto restaurant foods.

Water and produce parasites

Cyclospora, Cryptosporidium, and Giardia are protozoa linked to contaminated water and to produce irrigated, washed, or iced with that water. Cyclospora has a long record on berries, herbs, and other fresh produce. Cryptosporidium and Giardia cause prolonged watery diarrhea and are notorious in water-utility failures and in operations that use unsafe ice or unapproved well water. A bar that makes ice from a poorly protected water line is not running a “beverage program.” It is running a parasite vehicle.

Control is unglamorous: potable water from an approved source, ice made from that water only, produce from approved suppliers, and no “we rinsed it in the mop sink” improvisation. These organisms are chlorine-tolerant compared with many bacteria, which is another reason you do not treat a light produce rinse as sterilization. Cooking destroys them when the food is cooked. Salads are not cooked.

Meat and game parasites

Trichinella is the historical pork-and-wild-game roundworm. Commercial pork in the United States is a much smaller risk than it was a generation ago, but undercooked wild game — bear, wild boar, and similar hunter-donated meat — still belongs on a manager’s reject list unless it comes through an approved, inspected channel and is cooked thoroughly. A CFPM does not accept a hunter’s roast as a weekend special because “we know the family.”

Fish parasites and Food Code freezing

Anisakis and related worms live in some marine fish. Guests who eat raw or undercooked fish — sushi, sashimi, ceviche, cold-smoked items that are not otherwise treated — can acquire them. The Food Code answer is not “our chef can see the worms.” The answer is a two-part control: buy from an approved supplier, and apply parasite destruction when the fish will be served raw or undercooked.

Food Code parasite destruction is a freezing schedule, not a refrigerator set-point. The commonly tested options are freezing and storing at -4°F (-20°C) or below for 7 days (168 hours); freezing at -31°F (-35°C) or below until solid and storing at that temperature for 15 hours; or freezing at -31°F until solid and then storing at -4°F or below for 24 hours. A sushi cooler at 41°F does not freeze parasites. Certain farmed fish and some tuna species have written exceptions when the supplier documents them. Molluscan shellfish are a different hazard profile (viruses and bacteria, not this freeze rule). If you serve raw fish, you need the paperwork, not a verbal “it’s sushi-grade.”

Fungi: mold, yeast, and mycotoxins

Fungi in food service are mostly mold and yeast. They are biological hazards, but they behave differently from Big Six pathogens. Many are spoilage organisms that advertise themselves: fuzzy colonies, off odors, a fermented or alcoholic smell in a product that should not be fermenting. Some molds also make mycotoxins. Aflatoxin on poorly stored grains, corn, and nuts is the name to recognize. You cannot see aflatoxin the way you see a green colony, which is why approved suppliers and dry, pest-free storage matter more than a “we’ll cut the bad spot off the bulk bin” plan.

Mold on food — the conservative CFPM rule

Mold roots (hyphae) travel farther than the spot you can see. Soft, high-moisture, TCS foods give those roots a highway. The conservative, exam-safe rule is:

• Discard moldy TCS and soft foods. Leftover chicken salad, sour cream, yogurt, soft cheese, deli loaves, cooked leftovers, casseroles, and sliced fruit are not trimmed. The whole item goes.
• Hard cheeses and some firm produce are the narrow exception in some training texts: a manager may cut away the mold plus a generous margin (often taught as about 1 inch) on hard cheese such as cheddar, or on firm vegetables such as a solid head of cabbage, if the remainder still looks and smells sound.
• Exam items usually want discard of moldy TCS. If the question gives you leftover chili, cottage cheese, or a pan of cooked rice with mold, do not invent a trim. Throw it out.

Never scrape mold off and mix the remainder into a new batch. Never serve “just the other side” of a moldy portion. Never assume cooking destroys every mycotoxin.

Yeast

Yeast shows up as bubbles, an alcoholic or yeasty odor, slime, or pink discoloration in jams, jellies, honey, and other high-sugar foods that people assume are immortal. Yeast spoilage means the product is no longer the product you bought. Discard it. Acid and sugar slow many bacteria; they do not make a swollen jam jar safe. A swollen, fizzy, or oddly fermented preserve is a receiving or storage failure, not a candidate for the toast station.

Bacteria vs viruses vs parasites vs fungi

The exam will mix these four columns on purpose. If the item is Norovirus on a salad, do not reach for a thermometer. If the item is Anisakis in sashimi, do not reach for a hand sink as the only control. If the item is mold on chicken salad, do not reach for a knife.