Salmonella food poisoning is a food poisoning caused by the Salmonella bacterium. The infection causes swelling of the lining of the stomach and intestines (gastroenteritis) leading to symptoms such as fever, headache, abdominal pain, bloody diarrhea...
Salmonella bacterium causes one of the most common enteric (intestinal) infections in the United States and Europe – Salmonellosis. It is the second most common bacterial foodborne illness reported (after Campylobacter infection). The poisoning typically occurs in small, localized outbreaks in the general population or in large outbreaks in hospitals, restaurants, or institutions for children or the elderly.
The reported incidence of Salmonella illnesses is about 14 cases in 100,000 persons, which makes approximately 30,000 confirmed cases of salmonellosis a year in the U.S. True incidence is undoubtedly much higher as many milder cases never get diagnosed.
Anyone may contract Salmonella food poisoning, but the disease may get serious in those people with weakened immune systems such as infants, the elderly, and people with AIDS. In these people, the infection may even spread from the intestines to the blood stream, and further to other body sites, causing death if not promptly treated with antibiotics.
Particularly susceptible to Salmonella food poisoning are people who have had part or all of their stomach or their spleens removed, who have sickle cell anemia, cirrhosis of the liver, leukemia, lymphoma, malaria, louse-borne relapsing fever and Acquired Immunodeficiency Syndrome (AIDS).
Approximately 600 deaths are caused by Salmonella infections in the U.S. every year, which is 31 percent of all food-related deaths.
Sources of Salmonella infection
Any kind of food, drink or pharmaceuticals can be tainted with Salmonella. The most common sources of Salmonella infection are milk and eggs, but also meat, fresh fruits and vegetables may get contaminated. Children can get Salmonella from playing and taking care of pet chicks, ducks, farm animals, turtles and iguanas. Water too can get contaminated and along with milk, it affects the largest number of people just because of the mass consumption.
Animal or human feces with Salmonella can end up in your food when:
- An infected person preparing the food may not wash their hands properly after going to the bathroom – this is how small quantities of feces on the hands may get on the food.
- Eggs may have chicken feces on the shell that contaminate food when the egg is cracked. Milk may be contaminated with cow feces.
- Salmonella can be on the outside of fruits or vegetables if the plants are grown near animals. The fruit gets contaminated when it is sliced, as bacteria from the outside are carried to the inside on the knife.
Chickens are a major carrier of Salmonella bacteria. Improperly handled or undercooked poultry and eggs most frequently cause Salmonella food poisoning.
Identifying contaminated foods is quite difficult because infected chickens show no signs or symptoms.
It was first thought that Salmonella bacteria appears in eggs that had cracked, allowing the bacteria to enter. However, it was learned later, that the egg shells have tiny pores and that even uncracked eggs could become contaminated. Additionally, bacteria can be passed from the infected female chicken directly into the substance of the egg before the shell has formed around it.
Various sources for Salmonella food poisoning mention 8 most common symptoms of Salmonella food poisoning
- Sudden onset of symptoms
- Severe headache
- Vomiting, which is less common than diarrhea
- Bloody Diarrhea with mucous
- Abdominal cramps
- Fever, which is almost always present
- Flu-like symptoms
- Loss of appetite
- Myalgias (muscle pain)
- Arthralgias (joint pain)
The onset of symptoms usually occurs within 6 to 72 hours after the ingestion of Salmonella bacteria. The infectious dose is small, from 15 to 20 cells.
Salmonella infection can sometimes result in Reiter’s Syndrome, which can be referred as “reactive arthritis”. Reiter’s Syndrome is an uncommon condition but when it does occur, it is debilitating. Symptoms of this condition include at least two out of three seemingly unrelated symptoms: reactive arthritis, conjunctivitis (eye irritation), and urinary tract infection and appear between one and three weeks following the infection.
“Reiter’s arthritis” typically affects the knees, ankles, and feet and causes pain and swelling in these areas but wrists, fingers and other joints may also get be affected, with less frequency though.
Most commonly, Salmonella food poisoning require no treatment as the infections resolve in five to seven days on their own. Treatment is needed only if the affected person becomes severely dehydrated or the infection spreads from the intestines.
Dangers of dehydration
Signs of dehydration include increased thirst, dark urine, decreased, urine output, dry tongue or the mucous membranes in the mouth, dry and chapped skin and general weakness. Dehydration usually follows frequent diarrhea and vomiting that drain the body of fluids, salts and minerals. It occurs if the infected person loses more liquid than they can take in.
Dehydration can be pretty serious in babies and the elderly. Re-hydration is often done with intravenous fluids.
In case the infection spreads from the intestines or otherwise persists, treatment with antibiotics may be necessary.
For these purposes, doctors usually prescribe ampicillin, gentamicin, trimethoprim/sulfamethoxazole, or ciprofloxacin.
Some Salmonella bacteria have even become resistant to antibiotics, possibly as a result of the use of antibiotics to promote the growth of feed animals.
For those who had developed Reiter’s Syndrome and are suffering from reactive arthritis, symptomatic treatment with high doses of a nonsteroidal anti-inflammatory drugs and steroid injections into affected joints may be ordered.
Severe joint inflammation may be handled with injections of corticosteroids directly into the affected joint to reduce the inflammation. In cases where severe inflammation symptoms cannot be controlled with these treatments, medications that suppress the immune system, such as sulfasalazine or methotrexate, may prove effective. Gradually introduced exercise may help improve joint function.
In case Salmonella gets complicated
Like already mentioned, Salmonella can be dangerous in the very young, the very old and anyone with a weakened immune system, such as those with HIV/AIDs. Complications of Salmonella infection involve infection of the entire body, or in certain parts causing a type of arthritis, abscesses, heart infection, pneumonia and kidney problems, among other health problems.
In such cases, antibiotics may be prescribed. For most types of salmonella cases, Ciprofloxacin is the antibiotic of choice for the adults. Children should not take ciprofloxacin, and are prescribed amoxicillin or ampicillin instead. Their treatment needs to be under supervision of a pediatrician.
In some parts of the U.S. and Europe, bacterial resistance to ciprofloxacin is widespread). If this is the case, TMP-SMX and chloramphenicol can be used as second line of drugs when the Salmonella strain is resistant to the first treatment of antibiotics.
Preventing Salmonella infection
In order to prevent salmonellosis, you should thoroughly cook poultry, ground beef, and eggs before eating. Eggs must be cooked at least until the yoke is solid. Meat and poultry must reach 160ºF or higher throughout.
The most vulnerable are infants, the elderly, those with a compromised immune system, including diabetics, pregnant women, HIV/AIDS patients, cancer and transplant patients, so extra care should be paid when preparing foods for them.
No drinks and foods containing raw eggs should be consumed including homemade eggnog and hollandaise sauce. Raw (unpasteurized) milk or products made from raw milk should be avoided.
Basic rules for preparing food hygienically are:
- Always washing your hands with soap after going to the toilet and before preparing food and drying them on a dry towel.
- Washing your hands when switching from preparing one type of food to another, eg vegetables to meat as this helps prevent the exchange of bacteria between different ingredients.
- Properly wash kitchen utensils with soap and water before use with another type of food. This too stops bacteria from being exchanged.
- Food should be stored in the refrigerator. Meat, poultry and fish must not be left out of the fridge for long periods.
By being aware of the incidence, causes and symptoms and by following these simple rules for prevention, you are doing a great job avoiding the unnecessary and annoying Salmonella infection.