Salmonellosis

What is salmonellosis?

Salmonellosis is a type of food poisoning caused by the salmonella bacterium. There are many different kinds of these bacteria; Salmonella typhimurium and Salmonella enteritidis are the most common types in the United States.

Every year, approximately 40,000 cases of salmonellosis are reported in the U.S. Because many milder cases are not diagnosed or reported, the actual number of infections may be 30 or more times greater.¹ Salmonellosis is more common in the summer than winter. Children are the most likely to get salmonellosis; young children, older adults, and people with impaired immune systems are the most likely to have severe infections.

What causes salmonellosis?

You can get salmonellosis by eating food contaminated with salmonella. This can happen in the following ways:

• Food may be contaminated during food processing or food handling.
• Food may become contaminated by the unwashed hands of an infected food handler. A frequent cause is a food handler who does not wash his or her hands with soap after using the bathroom.
• Salmonella may also be found in the feces of some pets, especially those with diarrhea. You can become infected if you do not wash your hands after contact with these feces.
• Reptiles, baby chicks and ducklings, and small rodents such as hamsters are particularly likely to carry salmonella. You should always wash your hands immediately after handling one of these animals, even if the animal is healthy. Adults should also be careful that children wash their hands after handling reptiles, baby chicks or ducklings, or small rodents.

Beef, poultry, milk, and eggs are most often infected with salmonella. However, vegetables may also be contaminated. Contaminated foods usually look and smell normal.

What are the symptoms?

Symptoms of salmonellosis include diarrhea, fever, and abdominal cramps. They develop 12 to 72 hours after infection, and the illness usually lasts 4 to 7 days. Most people recover without treatment. However, diarrhea and dehydration may be so severe that it is necessary to go to the hospital. Older adults, infants, and those with impaired immune systems are at highest risk.

If you only have diarrhea, you usually recover completely, although it may be several months before your bowel habits are entirely normal. A small number of people who are infected with salmonellosis develop Reiter's syndrome, a disease that can last for months or years and can lead to chronic arthritis.

How is salmonellosis diagnosed?

Salmonellosis is diagnosed based on a medical history and physical exam. Your health professional will ask you questions about your symptoms, foods you have recently eaten, and your work and home environments. A stool culture and blood tests may be done to confirm the diagnosis.

How is it treated?

You treat salmonellosis by managing any complications until it passes. Dehydration caused by diarrhea is the most common complication. Antibiotics are not usually needed unless the infection has spread.

To prevent dehydration, take frequent sips of a rehydration drink (such as Lytren, Rehydralyte, or Pedialyte). Try to drink a cup of water or rehydration drink for each large, loose stool you have. Sports drinks, soda pop, and fruit juice contain too much sugar and not enough of the important electrolytes that are lost during diarrhea and should only be taken alternately with a rehydration drink.

Try to stick to your normal diet as much as possible. Eating your usual diet will help you to get enough nutrition. Doctors believe that eating a normal diet will also help you feel better faster. But try to avoid foods that are high in fat and sugar. Also avoid spicy foods, alcohol, and coffee for 2 days after all symptoms have disappeared.

How can I prevent salmonellosis?

To prevent salmonellosis:

• Do not eat raw or undercooked eggs. Raw eggs may be used in some foods such as homemade hollandaise sauce, Caesar and other salad dressings, tiramisu, homemade ice cream, homemade mayonnaise, cookie dough, and frostings.
• Cook foods until they are well done. Use a meat thermometer to be sure foods are cooked to a safe temperature. Do not use the color of the meat (such as when it is no longer "pink") to tell you that it is done.
• Avoid raw or unpasteurized milk or other dairy products.
• Wash or peel produce before eating it.
• Avoid cross-contamination of food. Keep uncooked meats separate from produce, cooked foods, and ready-to-eat foods. Thoroughly wash hands, cutting boards, counters, knives, and other utensils after handling uncooked foods.
• Wash your hands before handling any food and between handling different food items.
• Do not prepare food or pour water for others when you have salmonellosis.
• Wash your hands after contact with animal feces. Since reptiles are particularly likely to carry salmonella bacteria, wash your hands immediately after handling them. Consider not having reptiles (including turtles) as pets, especially if you have small children or an infant.

[Adapted from the U.S. Centers for Disease Control and Prevention]

• Food Poisoning and Safe Food Handling

Citations

1. Centers for Disease Control and Prevention (2005). Salmonellosis. Available online: http://www.cdc.gov//ncidod/dbmd/diseaseinfo/salmonellosis_g.htm.