It strikes mostly in the warmer months of the year and is transmitted by infected, undercooked, or raw seafood. Parasites rarely cause food poisoning. When they do, they are usually swallowed in contaminated or untreated water and cause long-lasting but mild symptoms. It is transmitted by drinking contaminated water, often from lakes or streams in cooler mountainous climates. It is transmitted by contaminated drinking water.
Toxic agents are the least common cause of food poisoning.
Often there is nausea, vomiting, and diarrhea. Some types of mushrooms produce a nerve toxin, which causes sweating, shaking, hallucinations, and coma. It is transmitted by eating certain large game fish from tropical waters most specifically barracuda and jacks. It is transmitted in seafood, mostly mahi-mahi and tuna, but can also be in Swiss cheese. Toxins are transmitted by eating unwashed fruits or vegetables contaminated with pesticides.