The World Health Organization (WHO) has updated its fact sheet on non-typhoidal Salmonella.

Background Information:

The burden of foodborne diseases is substantial: every year almost 1 in 10 people fall ill and 33 million of healthy life years are lost.

Foodborne diseases can be severe, especially for young children. Diarrhoeal diseases are the most common illnesses resulting from unsafe food, 550 million people falling ill each year, including 220 million children under the age of 5 years.

Salmonella is 1 of the 4 key global causes of diarrhoeal diseases.

Salmonella is a gram negative bacillus genus belonging to the Enterobacteriaceae family.

Within 2 species- Salmonella bongori and Samonella enterica- over 2500 different serotypes or serovars have been identified to date.

Salmonella is a ubiquitous and hardy bacteria that can survive several weeks in a dry environment and several months in water.

Key Messages:

The Disease

Salmonellosis is a disease caused by the bacteria Salmonella. It is usually characterized by acute onset of fever, abdominal pain, diarrhoea, nausea and sometimes vomiting.

The onset of disease symptoms occurs 6–72 hours (usually 12–36 hours) after ingestion of Salmonella, and illness lasts 2–7 days.

Symptoms of salmonellosis are relatively mild and patients will make a recovery without specific treatment in most cases. However, in some cases, particularly in children and elderly patients, the associated dehydration can become severe and life-threatening.

Sources and transmission

• Salmonella bacteria are widely distributed in domestic and wild animals. They are prevalent in food animals such as poultry, pigs, and cattle; and in pets, including cats, dogs, birds, and reptiles such as turtles.
• Salmonella can pass through the entire food chain from animal feed, primary production, and all the way to households or food-service establishments and institutions.
• Salmonellosis in humans is generally contracted through the consumption of contaminated food of animal origin (mainly eggs, meat, poultry, and milk), although other foods, including green vegetables contaminated by manure, have been implicated in its transmission.
• Person-to-person transmission can also occur through the faecal-oral route.
• Human cases also occur where individuals have contact with infected animals, including pets. These infected animals often do not show signs of disease.

Treatment

Treatment in severe cases is electrolyte replacement (to provide electrolytes, such as sodium, potassium and chloride ions, lost through vomiting and diarrhoea) and rehydration.

Routine antimicrobial therapy is not recommended for mild or moderate cases in healthy individuals.  (Antimicrobials may not completely eliminate the bacteria and may select for resistant strains, which subsequently can lead to the drug becoming ineffective.)

Prevention

Preventive measures for Salmonella in the home are similar to those used against other foodborne bacterial diseases (see recommendations for food handlers below).

Recommendations for the public and travellers

The following recommendations will help ensure safety while travelling:

• Ensure food is properly cooked and still hot when served.
• Avoid raw milk and products made from raw milk. Drink only pasteurized or boiled milk.
• Avoid ice unless it is made from safe water.
• When the safety of drinking water is questionable, boil it or if this is not possible, disinfect it with a reliable, slow-release disinfectant agent (usually available at pharmacies).
• Wash hands thoroughly and frequently using soap, in particular after contact with pets or farm animals, or after having been to the toilet.
• Wash fruits and vegetables carefully, particularly if they are eaten raw. If possible, vegetables and fruits should be peeled.

Recommendations for food handlers

WHO provides the following guidance for people handling food:

• Both professional and domestic food handlers should be vigilant while preparing food and should observe hygienic rules of food preparation.
• Professional food handlers who suffer from fever, diarrhoea, vomiting or visible infected skin lesions should report to their employer immediately.
• The five keys to Safer Food are:
  • keep clean
  • separate raw and cooked
  • cook thoroughly
  • keep food at safe temperatures
  • use safe water and raw materials.

Useful Links:

Link to the updated fact sheet:

http://who.int/mediacentre/factsheets/fs139/en/

Link to WHO’s ‘A guide on safe food for travellers’ (2010) (several languages):

http://who.int/foodsafety/publications/travellers/en/

Link to WHO’s ‘Five keys to safer food’ manual (several languages):

http://who.int/foodsafety/publications/5keysmanual/en/