Salmonella

1. Basic Facts About Salmonella

What Is Salmonella?

Salmonellosis, or salmonella, is an illness caused by rod-shaped, gram-negative bacteria of the genus Salmonella. The species most often responsible for illness in people is Salmonella enterica (S. enterica), which is found in warm-blooded mammals and the environment. The most common form of salmonellosis is a foodborne illness that results from an infection of the gastrointestinal tract. However, in some parts of the world, the S. enterica serotype Typhi can invade the bloodstream and cause a severe and occasionally life-threatening infection known as typhoid fever.

Salmonella Symptoms

Symptoms of a foodborne salmonella infection include vomiting, diarrhea, abdominal cramps and fever. They can appear within 12 to 72 hours after infection. In most people, the illness lasts anywhere from four to seven days and usually resolves without treatment. However, the very young, the elderly and those with chronic health conditions or compromised immune systems are more susceptible to infection, and the illness may be more severe, leaving them at risk of dehydration.¹

Symptoms of typhoid fever may not appear until six to 30 days after infection and include weakness, a very high and persistent fever, constipation, headaches and, in some people, a skin rash. Diarrhea is uncommon and vomiting not severe. Symptoms may last for several months if left untreated. It is most common in people who have traveled in countries where hygiene standards are low and where food and drinking water may be contaminated.²

Who Is at Risk?

Anyone is at risk of a foodborne illness caused by salmonella, but children under 5 are at an increased risk and have the highest incidence in the U.S. The percentage of those with severe infections that require hospitalization is highest among the elderly, and deaths in this group are also highest.³ As with many infections, people with chronic conditions or compromised immune systems — such as people with HIV, diabetes, rheumatological conditions or sickle cell disease, and those using corticosteroids — may be at an increased risk of serious illness from salmonella infections.⁴ Other groups with an increased risk of contracting a salmonella infection include infants who are not breastfeeding⁵ and people using medications that can reduce stomach acid production.⁶

How Are Salmonella Infections Diagnosed?

Because the symptoms of salmonella are vague and can be caused by a variety of infections, a laboratory diagnosis is required to confirm the presence of Salmonella bacteria. The testing process involves trying to grow the bacteria from a sample of stool, blood or other specimen. Salmonella that grow are considered “culture confirmed” and may then be subjected to a range of biochemical tests to identify the specific subspecies.⁷ The initial testing and confirmation of salmonella may be done by a hospital’s clinical diagnostic laboratory, but further identification is often done by a state or territorial public health laboratory. Data on salmonella outbreaks and cases is collected by the U.S. Centers for Disease Control and Prevention (CDC) as part of its regular enteric disease surveillance.⁸

2. The Burden of Foodborne Illness Caused by Salmonella

The CDC’s Foodborne Diseases Active Surveillance Network tracks salmonella infections in the United States that have been confirmed by culture or diagnostic tests. Preliminary figures for 2016 reveal that just over 50,000 non-typhoidal salmonella cases were reported, and they were responsible for approximately 15,000 hospitalizations and 260 deaths.⁹ However, the number of cases is believed to be underdiagnosed by a factor of 30¹⁰ so the actual number of annual cases is probably closer to 1.5 million, an incidence of around 16 per 100,000 people.¹⁰  In 2015, 158 of 902 foodborne illness outbreaks were confirmed or suspected salmonella.¹¹ These illnesses are usually caused by serotypes of S. enterica, the most common of which are S. typhimurium, S. enteritidis and S. newport. Much of the burden of illness from salmonella, including hospitalizations and deaths, is borne by children under age 5 and the elderly.

3. How Salmonella Spreads

Direct Contact

Salmonella is found in a variety of foods. While commonly occurring in eggs and poultry, it can also be found in beef, fish and pork. Fruits and vegetables such as sprouts and leafy greens can also become contaminated after coming into contact with the infected feces of animals roaming on produce fields.¹² Water in drinking wells can also become contaminated with salmonella.

The most common way of getting sick from salmonella is eating contaminated foods, which usually look and smell normal. Because salmonella must survive the acidic environment of the gut, a relatively large number of the bacteria is required to develop an illness. You may eat contaminated food without realizing it and without getting an infection. Single infections and outbreaks have also occurred following direct contact with animals such as frogs, toads and other amphibians. Direct transmission from person to person can also spread salmonella, but this is rare.

The Role of Surfaces in the Spread of Salmonella

Salmonella may also spread via environmental surfaces that have come into contact with contaminated foods, or the contaminated hands of food service workers, which then contaminate other foods. Restaurants, catering business and food-handling facilities are at the greatest risk, although transmission may also occur in households.

4. Salmonella Treatment

Most cases of salmonella resolve without medical treatment after a few days. However, whenever there is diarrhea, there is a risk of dehydration. According to the Mayo Clinic, people with the symptoms of a salmonella illness should drink lots of fluids to stay hydrated. If you are severely dehydrated and require hospitalization, intravenous administration of liquids and electrolytes may be required. Anti-diarrheal medication may also be prescribed to relieve abdominal cramping, but this may actually prolong the symptoms of diarrhea.¹³

In cases where the salmonella infection is severe or has entered the bloodstream, or if the patient is immunocompromised, antibiotics may be prescribed.¹³

5. Preventing Foodborne Illnesses Caused by Salmonella

Handling Food in the Kitchen

The CDC describes a number of steps you can take to reduce the risk of getting a salmonella infection from contaminated food. These include washing hands before and after handling raw meat, seafood or eggs; cleaning utensils with hot soapy water after using them on raw foods; and sanitizing cutting boards and surfaces with a dilute solution of bleach after use. Ensuring that food is cooked thoroughly is also a good step to prevent illness from salmonella. Food should also be separated to ensure that potentially contaminated items are not mixed with other foods. Prepared or perishable foods should be refrigerated correctly and within two hours of preparation.¹²

Cleaning and Disinfection of Environmental Surfaces

In restaurants, catering facilities and other food preparation areas, proper cleaning, disinfection and sanitizing of surfaces is essential to reducing the spread of foodborne illness caused by salmonella. There is a wide range of products available, and it’s important to read the directions for use before you clean. Some disinfectants may require a rinse step after application and before the surface can come into contact with food, while other food-safe sanitizers can be applied directly to surfaces and allowed to dry. To ensure disinfection and sanitization efficacy, soap and water should be used to clean off gross soil and organic material prior to application of the product.

Hand Hygiene

If you work in a restaurant or catering facility, hand washing is critical. Hands should be washed vigorously with soap and warm water for more than 20 seconds and at the following times:

6. CloroxPro Products with EPA-Approved Claims Against Salmonella

The following Clorox Healthcare and CloroxPro disinfectant products have EPA-approved claims against Salmonella enterica, the most common species of Salmonella that causes illness. Always follow the directions for use on the label when cleaning and disinfecting.