International
oi-Madhuri Adnal
Washington, Oct 22: More than 650 people across 37 states in the United States have fallen sick due to a salmonella outbreak. The outbreak has been traced to onions imported from Chihuahua in Mexico and distributed throughout the United States by ProSource Inc., US health officials said.
The Centers for Disease Control and Prevention has advised people to throw out any whole red, white and yellow onions that do not have a sticker or packaging. No deaths have been reported due to the infection so far.
What is Salmonellosis?
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.
Although large Salmonella outbreaks usually attract media attention, 60-80% of all salmonellosis cases are not recognized as part of a known outbreak and are classified as sporadic cases, or are not diagnosed as such at all.
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. This is because antimicrobials may not completely eliminate the bacteria and may select for resistant strains, which subsequently can lead to the drug becoming ineffective.
However, health risk groups such as infants, the elderly, and immunocompromised patients may need to receive antimicrobial therapy. Antimicrobials are also administered if the infection spreads from the intestine to other body parts.
Because of the global increase of antimicrobial resistance, treatment guidelines should be reviewed on a regular basis taking into account the resistance pattern of the bacteria based on the local surveillance system.
Prevention methods
- Prevention requires control measures at all stages of the food chain, from agricultural production, to processing, manufacturing and preparation of foods in both commercial establishments and at home.
- Preventive measures for Salmonella in the home are similar to those used against other foodborne bacterial diseases (see recommendations for food handlers below).
- The contact between infants/young children and pet animals that may be carrying Salmonella (such as cats, dogs, and turtles) needs careful supervision.
- National and regional surveillance systems on foodborne diseases are important means to know and follow the situation of these diseases and also to detect and respond to salmonellosis and other enteric infections in early stages, and thus to prevent them from further spreading.
Story first published: Friday, October 22, 2021, 17:46 [IST]