Salmonella
Salmonella is a bacterial infection that you usually get from eating improperly handled food. Generally, somewhere along the food processing line, someone didn’t wash their hands after using the toilet.
Salmonella has been found in tuna. Freezing the fish won’t stop you from getting salmonella. Cooking can keep you from getting salmonella as long as the contamination didn’t occur after your food was cooked. If you’ve had stomach flu, you’ve probably had salmonella.