A foodborne illness can be contracted from shrimp, though the risk is usually connected to handling rather than the shrimp being the original host. The responsible bacterium is Salmonella, a common cause of gastroenteritis worldwide. This bacterium lives in the intestinal tracts of animals and humans and is shed through feces, making it a widespread environmental contaminant. Ingesting a sufficient amount of the live bacteria causes salmonellosis.
How Shrimp Become Contaminated
Salmonella contamination typically begins in the environment before the product reaches a retail store. Most outbreaks are linked to shrimp raised in aquaculture environments rather than wild-caught varieties. Farming ponds can become contaminated through fecal runoff from livestock, contaminated feed, or waste from wild animals like birds and reptiles.
The shrimp may internalize the bacteria or carry it on their shells and gills. Contamination also occurs during harvesting and processing stages. Poor hygiene, such as using unclean water or ice to wash or store the shrimp, can introduce the bacteria.
Surfaces that contact the product, including processing tables, knives, and workers’ hands, can transfer Salmonella if sanitation is inadequate. Cross-contamination is a significant issue during transport or retail display. If raw shrimp juices leak onto ready-to-eat foods, the contamination pathway is established, creating a risk for the consumer.
Identifying Symptoms of Food Poisoning
Salmonellosis often presents with symptoms similar to the stomach flu. Symptoms generally occur between six hours and six days after consuming the contaminated shrimp. Common signs include diarrhea, abdominal cramps, fever, nausea, and vomiting.
For most healthy individuals, the illness resolves within four to seven days without specific medical treatment. Diarrhea can be severe and prolonged, sometimes lasting up to ten days. Dehydration is a concern, especially in vulnerable populations like the elderly, young children, and those with weakened immune systems.
A person should seek immediate medical attention if they experience a high fever exceeding 102°F, have bloody stools, or show signs of severe dehydration. Indicators of dehydration include a dry mouth, reduced urination, and dizziness when standing up. Timely intervention can prevent the infection from spreading from the intestines to the bloodstream, a rare but serious complication.
Preventing Salmonella Through Safe Preparation
The most effective way to prevent salmonellosis is by ensuring shrimp is cooked to the correct internal temperature. Raw shrimp must reach a minimum internal temperature of 145°F (63°C) to destroy harmful bacteria. Visually, the shrimp will turn opaque and pink or red, and the flesh will be firm when safely cooked.
Proper thawing methods are important, as thawing at room temperature allows bacteria to multiply rapidly. The safest method is thawing frozen shrimp overnight in the refrigerator. A faster alternative is submerging the shrimp in a sealed plastic bag in cold tap water, changing the water every 20 to 30 minutes until thawed.
Shrimp thawed using cold water or a microwave should be cooked immediately. Once thawed, raw shrimp should not remain in the refrigerator for more than two days. The risk of cross-contamination must be addressed by keeping raw shrimp separate from all other ready-to-eat foods.
This separation includes using different cutting boards and utensils for the raw seafood. Thoroughly wash hands, knives, and preparation surfaces with hot, soapy water immediately after handling the shrimp. These measures prevent the transfer of bacteria to foods that will not be cooked.