By Mara P. Paradis, M.D.
The salmonella infection is a leading cause of foodborne illness in the United States. It has been known to cause illness for nearly 125 years. Infection is more likely to occur in summer months. Young children, people over 65 and those with weakened immune systems are most likely to develop a severe infection. Children under the age of 5 have higher rates of infection than any other age group.
Causes of Salmonellosis
Salmonella lives in the intestinal tracts of humans and animals and can be harmless. When it causes infections, it is usually transmitted by eating animal-based food products (such as meat, produce, eggs) that have been contaminated. Drinks (water and milk) can also become contaminated with salmonella.
Contamination is caused by:
Symptoms of Salmonellosis
Most people develop symptoms within 12-72 hours of infection, with cases normally lasting four to ten days. Symptoms include:
Some severe cases of diarrhea may result in hospitalization, although this is rare. The symptoms usually lessen in time, but it may take several weeks for bowel movements to return to normal.
Testing of a stool sample can be done to determine if salmonella is the cause of these symptoms.
Like many cases of food poisoning (link to new food poisoning article), salmonellosis usually passes without medical intervention, except in extreme cases. It is important to drink a lot of fluid to combat dehydration, rest and eat bland foods for a few days in order to give the gastrointestinal tract time to recover.
In cases of invasive salmonellosis, medical intervention is necessary. Invasive infections occur in approximately five percent of cases and are rarely fatal. Types of invasive salmonellosis include:
People most likely to develop invasive infections are the very young and very old.