3.2 The Big 6 Pathogens & Employee Illness Policy
Key Takeaways
- The FDA's Big 6 highly infectious pathogens are Norovirus, Hepatitis A virus, Shigella spp., Shiga toxin-producing E. coli (STEC), Salmonella Typhi, and nontyphoidal Salmonella.
- Exclusion bars an employee from the establishment entirely, while restriction allows work but bars contact with exposed food, clean equipment/utensils/linens, and unwrapped single-service items.
- Vomiting or diarrhea while on duty triggers immediate exclusion regardless of the suspected cause.
- Salmonella Typhi requires the most rigorous return-to-work clearance of the Big 6 because infected individuals can become long-term carriers.
- Sore throat with fever in a food handler triggers restriction, not automatic exclusion.
Some foodborne pathogens are so infectious — meaning a very small number of organisms can cause illness — that the FDA (Food and Drug Administration) Food Code singles them out for mandatory reporting and specific work restrictions. These six pathogens are commonly called the Big 6:
- Norovirus
- Hepatitis A virus
- Shigella spp.
- Shiga toxin-producing Escherichia coli (STEC)
- Salmonella Typhi
- Nontyphoidal Salmonella
A food employee who is diagnosed with, or is experiencing symptoms consistent with, one of these pathogens must report that information to the person in charge (PIC) immediately — even mid-shift. Many operations formalize this duty with a written Employee Health Policy that new hires read and sign at the time of hire, often paired with a conditional employee interview (asking about recent illness) before the person is allowed to start working with food.
Exclusion vs. Restriction
The Food Code distinguishes between two levels of response to a sick or potentially infectious employee:
- Exclusion: the employee may not work in the food establishment in any capacity, and may not even enter the establishment as a customer, until cleared to return.
- Restriction: the employee may continue working, but not in any role involving contact with exposed food, clean equipment or utensils, clean linens, or unwrapped single-service and single-use articles. A restricted employee might be moved to cashier duty, expediting, or paperwork, depending on the establishment's layout.
Which response applies depends on the specific pathogen or symptom, the employee's normal duties, and — for the higher-risk pathogens — direction from the local regulatory authority.
Symptom and Diagnosis Triggers
| Symptom / Diagnosis | Required Action | Why |
|---|---|---|
| Vomiting or diarrhea while on duty | Immediate exclusion | Applies regardless of suspected cause — a food employee may not work through active vomiting or diarrhea |
| Diagnosed with Norovirus | Exclusion | Extremely infectious even at low doses; can spread rapidly through a kitchen |
| Diagnosed with Hepatitis A virus | Exclusion | Jaundice is a classic sign; the virus can be shed before symptoms even appear |
| Diagnosed with Shigella spp. | Exclusion | Return typically requires medical/regulatory clearance |
| Diagnosed with STEC | Exclusion | Can cause severe illness; return typically requires medical/regulatory clearance |
| Diagnosed with Salmonella Typhi | Exclusion | Can create a long-term carrier state; clearance criteria are the most rigorous of the Big 6 |
| Diagnosed with nontyphoidal Salmonella | Exclusion or restriction | Depends on symptoms and role; regulatory authority may direct the specific response |
| Sore throat with fever (food handler) | Restriction | No contact with exposed food, clean equipment/utensils/linens, or unwrapped single-service items |
| Infected wound that cannot be adequately covered | Restriction, or exclusion if drainage can't be contained | See hand-covering rules in Section 3.4 |
Return-to-Work Criteria
Because the Big 6 pathogens differ in how long a person remains infectious after symptoms resolve, return-to-work criteria are not one-size-fits-all:
- Vomiting/diarrhea (general): typically requires the employee to be symptom-free for a defined period — commonly at least 24 hours — without relying on anti-diarrheal or anti-emetic medication to mask ongoing symptoms.
- Norovirus: exclusion generally continues until the employee has been asymptomatic for at least 24 hours; during a confirmed or suspected outbreak, the local regulatory authority may require a longer exclusion period.
- Salmonella Typhi: because infected individuals can become long-term carriers and continue shedding the organism after symptoms end, return typically requires medical clearance and, in many jurisdictions, negative stool sample documentation before the regulatory authority lifts the exclusion.
- Shigella spp. and STEC: return often requires medical clearance and may require negative stool sample results, particularly when the employee's role involves substantial food contact or the case is linked to a larger outbreak.
- Hepatitis A virus: exclusion criteria are tied to medical documentation and, in many jurisdictions, a minimum period after the onset of jaundice, plus regulatory authority sign-off.
- Nontyphoidal Salmonella: return is generally based on resolution of symptoms, with the local regulatory authority determining whether additional clearance is needed.
Because exact timeframes vary by jurisdiction and by the specific facts of a case, the manager's job is not to memorize every health department's precise day count, but to know the framework: report immediately, apply exclusion or restriction based on the pathogen or symptom, and involve the local regulatory authority before returning a Big-6-diagnosed employee to food-contact duties.
Why This Matters
The Big 6 pathogens are responsible for a disproportionate share of foodborne illness outbreaks traced back to a sick food employee who kept working. A manager who fails to ask the right questions, fails to act on a reported symptom, or lets an employee push through a shift with vomiting or diarrhea creates exactly the conditions the FDA Food Code's employee health provisions are designed to prevent. Expect scenario-based exam questions that describe a symptom or diagnosis and ask you to identify whether exclusion or restriction applies.
Which of the following pathogens is NOT one of the FDA Food Code's Big 6 highly infectious agents that trigger mandatory reporting to the person in charge?
A food employee begins vomiting while on duty. What is the immediate required action under the FDA Food Code?
An employee reports being diagnosed with Salmonella Typhi (typhoid fever) but currently feels well. Why does the FDA Food Code typically require a more rigorous return-to-work process for this diagnosis than for an ordinary case of nontyphoidal Salmonella?
A food handler reports a sore throat accompanied by fever. Under FDA Food Code guidance, what action applies?