| Bacillus cereus (diarrheal toxin) | 10–16 hours | ± | +++ | – | Toxin in meats, stews, and gravy. | Clinical. Food and stool can be tested for toxin. | Abdominal cramps, watery diarrhea, and nausea lasting 24–48 hours. Supportive care. |
| Bacillus cereus (preformed toxin) | 1–8 hours | +++ | ± | – | Reheated fried rice causes vomiting or diarrhea. | Clinical. Food and stool can be tested for toxin. | Acute onset, severe nausea and vomiting lasting 24 hours. Supportive care. |
| Campylobacter jejuni | 2–5 days | ± | +++ | + | Raw or undercooked poultry, unpasteurized milk, water. | Stool culture on special medium. | Fever, diarrhea that can be bloody, cramps. Usually self-limited in 2–10 days. Treat with azithromycin and secondarily fluoroquinolones for severe disease. May be associated with Guillain-Barré syndrome. |
| Clostridium botulinum | 12–72 hours | ± | – | – | Clostridia grow in anaerobic acidic environment eg, canned foods, fermented fish, foods held warm for extended periods. | Stool, serum, and food can be tested for toxin. Stool and food can be cultured. | Diplopia, dysphagia, dysphonia, respiratory embarrassment. Treatment requires clear airway, ventilation, and intravenous polyvalent antitoxin (see text). Symptoms can last for days to months. |
| Clostridioides difficile | Usually occurs after 7–10 days of antibiotics. Can occur after a single dose or several weeks after completion of antibiotics. | – | +++ | ++ | Associated with antibacterial drugs; clindamycin and beta-lactams most commonly implicated. Fluoroquinolones associated with hypervirulent strains. | Stool tested for toxin. | Abrupt onset of diarrhea that may be bloody; fever. Vancomycin 125 mg orally four times per day or fidaxomicin 200 mg twice daily for 10 days recommended over metronidazole. |
| Clostridium perfringens | 8–16 hours | ± | +++ | – | Clostridia grow in rewarmed meat and poultry dishes and produce an enterotoxin. | Stools can be tested for enterotoxin or cultured. | Abrupt onset of profuse diarrhea, abdominal cramps, nausea; vomiting occasionally. Recovery usual without treatment in 24–48 hours. Supportive care; antibiotics not needed. |
| Enterohemorrhagic Escherichia coli, including Shiga-toxin–producing E coli strains (STEC) | 1–8 days | + | +++ | – | Undercooked beef, especially hamburger; unpasteurized milk and juice; raw fruits and vegetables. | Shiga-toxin–producing E coli can be cultured on special medium. Other toxins can be detected in stool. | Usually abrupt onset of diarrhea, often bloody; abdominal pain. In adults, it is usually self-limited to 5–10 days. In children, it is associated with hemolytic-uremic syndrome (HUS). Antibiotic therapy may increase risk of HUS. Plasma exchange may help patients with STEC-associated HUS. |
| Enterotoxigenic E coli (ETEC) | 1–3 days | ± | +++ | ± | Water, food contaminated with feces. | Stool culture. Special tests required to identify toxin-producing strains. | Watery diarrhea and abdominal cramps, usually lasting 3–7 days. In travelers, fluoroquinolones shorten disease. |
| Noroviruses and other caliciviruses | 12–48 hours | ++ | +++ | + | Shellfish and fecally contaminated foods touched by infected food handlers. | Clinical diagnosis with negative stool cultures. PCR available on stool. | Nausea, vomiting (more common in children), diarrhea (more common in adults), fever, myalgias, abdominal cramps. Lasts 12–60 hours. Supportive care. |
| Rotavirus | 1–3 days | ++ | +++ | + | Fecally contaminated foods touched by infected food handlers. | Immunoassay on stool. | Acute onset, vomiting, watery diarrhea that lasts 4–8 days. Supportive care. |
| Salmonella species | 1–3 days | – | ++ | + | Eggs, poultry, unpasteurized milk, cheese, juices, raw fruits and vegetables. | Routine stool culture. | Gradual or abrupt onset of diarrhea and low-grade fever. No antimicrobials unless high risk (see text) or systemic dissemination is suspected. If susceptible, treatment with ceftriaxone, ciprofloxacin, TMP-SMZ, or amoxicillin is recommended. Prolonged carriage can occur. |
| Shigella species (mild cases) | 24–48 hours | ± | + | + | Food or water contaminated with human feces. Person to person spread. | Routine stool culture. | Abrupt onset of diarrhea, often with blood and pus in stools, cramps, tenesmus, and lethargy. Stool cultures are positive. Azithromycin, ciprofloxacin, or ceftriaxone are drugs of choice. Avoid fluoroquinolones if the ciprofloxacin MIC is 0.12 mcg/mL or greater. Do not give opioids. Often mild and self-limited. |
| Staphylococcus (preformed toxin) | 1–8 hours | +++ | ± | ± | Staphylococci grow in meats, dairy, and bakery products and produce enterotoxin. | Clinical. Food and stool can be tested for toxin. | Abrupt onset, intense nausea and vomiting for up to 24 hours, recovery in 24–48 hours. Supportive care. |
| Vibrio cholerae | 24–72 hours | + | +++ | – | Contaminated water, fish, shellfish, street vendor food. | Stool culture on special medium. | Abrupt onset of liquid diarrhea in endemic area. Needs prompt intravenous or oral replacement of fluids and electrolytes. Doxycycline is drug of choice if antibiotics are indicated. Ciprofloxacin, azithromycin, or ceftriaxone are alternatives. |
| Vibrio parahaemolyticus | 2–48 hours | + | + | ± | Undercooked or raw seafood. | Stool culture on special medium. | Abrupt onset of watery diarrhea, abdominal cramps, nausea and vomiting. Recovery is usually complete in 2–5 days. |
| Yersinia enterocolitica | 24–48 hours | ± | + | + | Undercooked pork, contaminated water, unpasteurized milk, tofu. | Stool culture on special medium. | Severe abdominal pain (appendicitis-like symptoms), diarrhea, fever. Polyarthritis, erythema nodosum in children. If severe, give TMP-SMZ. Alternatives are cefotaxime and ciprofloxacin. Without treatment, self-limited in 1–3 weeks. |