Foodborne illness from raw or undercooked shrimp typically develops within 24 to 72 hours, though symptoms can appear as quickly as 1-2 hours or be delayed up to a week depending on the pathogen involved. The most common culprits are bacteria like Vibrio species, Salmonella, and Listeria, as well as viruses such as Norovirus and Hepatitis A. Vibrio vulnificus, which naturally occurs in seawater, is particularly concerning for raw shrimp and can cause severe illness in people with compromised immune systems or liver disease. Symptoms typically include nausea, vomiting, diarrhea, abdominal cramps, and fever. The incubation period—the time between eating contaminated food and symptom onset—varies based on the specific pathogen, the amount of contamination, and individual factors like age and immune status. Most cases resolve within a few days with supportive care like hydration and rest, but severe infections may require medical attention. To minimize risk, shrimp should be cooked to an internal temperature of 145°F (63°C) until the flesh is opaque. If shrimp is consumed raw (as in sushi or ceviche), it should be labeled as sushi-grade or sashimi-grade, which indicates it has been frozen at specific temperatures to kill parasites—though this doesn't eliminate all bacterial or viral risks.