A new study has revealed that most Salmonella illnesses from raw chicken are caused by a few products that have high levels of virulent strains. The study was conducted by researchers from the University of Illinois Urbana-Champaign, US. The researchers suggest that regulation efforts should focus on detecting and preventing those types of high-risk contamination.

Salmonella infection is a common bacterial disease that affects your intestinal tract. The bacteria usually live in animal and human intestines and are shed through stool (faeces). Humans tend to get more infected when they consume contaminated water or foods. A lot of people suffering from the infection don’t have any symptoms. However, those who do develop diarrhoea, fever and stomach (abdominal) cramps within 8 to 72 hours after exposure. Mayo Clinic says that most healthy people recover within a few days to a week without any specific treatment. In certain cases when the infection spreads beyond the intestines, the condition can lead to life-threatening complications.

Study co-author Matt Stasiewicz, Associate Professor in the Department of Food Science and Human Nutrition (FSHN) at the varsity said that while the poultry industry has in the last two decades “lowered the frequency of Salmonella in poultry, the number of people who are getting sick from these pathogens has not declined.”

More than 2,600 serotypes, or sub-groups, of Salmonella bacteria exist. Although Salmonella Kentucky is one of the most common serotypes in the US chicken, it is less likely to cause human illnesses. In comparison, three more virulent strains have been linked to multiple outbreaks of salmonellosis.

For the study, the researchers used a mathematical method the team set different levels and serotype thresholds to estimate the risk of getting ill from each strain.

Published in the Journal of Food Protection, the study said, “The baseline calculations yielded an estimate of about two salmonellosis cases per 1 million servings of chicken consumed.”

Salmonella Kentucky showed less than 1 per cent of illness risk. But products with high levels of Enteritidis, Infantis, or Typhimurium serotypes showed 69 per cent to 83 per cent risk of illnesses. The findings can help the poultry industry to improve its processes and to find strategies to manage it.

However, the researchers stressed that consumers should still follow food safety guidelines when preparing poultry, such as washing their hands, avoiding cross-contamination, and ensuring the meat is properly cooked.

A person contracts the infection by eating raw or undercooked meat, poultry, and eggs or egg products or by drinking unpasteurised milk. These signs might last a few days to a week. Some of the common symptoms of Salmonella infection are:

Diarrhoea

Stomach (abdominal) cramps

Fever

Nausea

Vomiting

Chills

Headache

Blood in the stool.