The Unignorable Threat of Salmonella
Salmonella is a common foodborne pathogen. According to data released by the World Health Organization, over 100 million people worldwide are infected with Salmonella each year.
Recently, the first Salmonella Prevention and Health Promotion Expert Seminar, supported by the People's Daily Health Client, was held in Beijing. Experts at the event urged the public to pay attention to the dangers of Salmonella and increase awareness of food safety.
Accounts for Nearly 80% of Foodborne Illness Cases
"Salmonella is a common foodborne pathogen that, when infected, can cause symptoms like fever, nausea, vomiting, diarrhea, and in severe cases, it can even be life-threatening," explained Ding Gangqiang, Director of the Institute of Nutrition and Health at the Chinese Center for Disease Control and Prevention. Data from this center shows that in China, Salmonella infections account for approximately 70%-80% of foodborne illness cases caused by bacteria.
Ding Gangqiang pointed out that the peak period for Salmonella infections is from May to October each year. "In other words, we are currently in the summer peak season, so we need to be especially vigilant. Eggs and undercooked chicken are the primary sources of Salmonella infections, so we must ensure food safety, enhance monitoring and early detection of Salmonella infections, and promptly control related cases and outbreaks."
"Salmonella is a large group of bacteria, and strains like Typhoid Salmonella, Paratyphoid Salmonella, and Enteritis Salmonella can cause human infectious diseases or food poisoning," said He Jiguo, Associate Professor at the College of Food Science and Nutritional Engineering at China Agricultural University. The bacteria that make people sick primarily come from symptomatic carriers or carriers of the infection. Animals infected with Salmonella (such as poultry, pigs, cattle, rodents, or wild animals) are also important sources of contamination. Additionally, improper food handling during storage and processing can lead to cross-contamination.
"World Health Organization statistics show that approximately 115 million people get sick from Salmonella infections each year, with 370,000 of them dying as a result," said Yan Meiying, a researcher at the Institute for Infectious Disease Control and Prevention at the Chinese Center for Disease Control and Prevention. Recent disease burden surveys in several provinces in China found an annual incidence rate of about 245 per 100,000 people for Salmonella infections.
He Jiguo explained that the prevention and control of Salmonella contamination can be approached in five ways:
During raw material procurement, select fresh and industrially produced eggs whenever possible and ensure low-temperature transportation and storage.
For food production personnel, workers handling food directly should have health certificates and practice good hygiene.
In food processing facilities, pay attention to layout, prevent cross-contamination, maintain cleanliness, and strengthen the prevention of disease vectors like flies and cockroaches.
Concerning kitchen utensils and equipment, separate raw and cooked foods and clean and disinfect them regularly, using alcohol or ultraviolet light for sterilization.
During food preparation, ensure thorough cooking and consume the food promptly.
According to Ding Gangqiang, the prevention and control of Salmonella infections that cause foodborne illnesses and other infectious diseases requires joint efforts from all of society. This includes strengthening food safety and hygiene regulation, raising public health awareness, further enhancing scientific monitoring and control, and establishing a comprehensive monitoring system to prevent and control related cases and outbreaks in a timely manner.
The Urgent Need for Salmonella Control Standards for Egg Products_hair milos forman
"Eggs and egg products are highly detectable sources of Salmonella," said Yang Yanjun, a professor at the College of Food Science at Jiangnan University and a member of the Technical Committee of the National Egg Product Engineering Technology Research Center. The sources of Salmonella in egg products can be categorized into external and internal infections. External infections occur when the eggshell comes into direct contact with soil containing Salmonella or chicken feces. Internal infections happen when the laying hens are infected with Salmonella, and the bacteria enter the eggs from the hens. There is a significant difference between external and internal infections. For eggs with internal infections, unless they are cooked, no measures can eradicate Salmonella.
With the development of the economy and the improvement in people's living standards, there have been significant changes in how Chinese people prepare eggs. "Soft-boiled eggs, onsen eggs, and low-temperature cooking are popular, and these low-temperature egg products have significant advantages in retaining and absorbing nutrients," Yang Yanjun explained. Traditional cooking methods such as boiling, steaming, and frying are favorable for thorough sterilization, but research has shown that soft-boiled eggs heated at high temperatures for a short time have the highest protein digestibility and do not destroy the fat-soluble vitamins in the yolk. This change in cooking methods, however, may introduce potential risks associated with Salmonella, which cannot be ignored.
As the world's largest consumer of egg products, with an annual consumption of over 29 million tons of eggs (approximately 400 billion eggs), China's control of Salmonella in egg products becomes particularly crucial. "Changes in cooking methods and the pursuit of nutrition and health can bring some potential risks, which require us to establish stricter standards," Yang Yanjun said.
"China has always placed great emphasis on the prevention and control of Salmonella. Food safety regulations have strict requirements for the prevention and control of Salmonella. However, there is still a lack of source control standards for Salmonella in fresh eggs," Yang Yanjun said. "We need to draw from the experience of developed countries to establish a control method and standard for Salmonella in egg products that suits China's situation. It is recommended to implement Salmonella control throughout the entire industry chain, from sources, feed, hatching, breeding, poultry house environment, personnel movement, egg production, packaging, transportation, and more."
Focus on Vulnerable Groups
Experts explained that summer can be considered a natural breeding ground for pathogens. In the high-temperature environment of summer, increased humidity is conducive to the rapid multiplication of pathogens. Typically, food infected with Salmonella does not exhibit any surface changes or alterations in odor, making it difficult to detect based on appearance alone.
"After a person is infected with Salmonella, there is an incubation period, usually lasting 6 to 24 hours, and clinical symptoms manifest as gastroenteritis. These symptoms can include bloody diarrhea, vomiting, fever, and, in severe cases, persistent diarrhea or high fever. About 5% of infected individuals may experience invasive symptoms, such as bacteremia or meningitis," said Guo Lingyun, Deputy Chief Physician of the Department of Infectious Diseases at Beijing Children's Hospital. The more severe cases are mainly found in "vulnerable groups," namely children and the elderly, who are more likely to experience severe infections.
"Salmonella has a significant impact on children's health," Meiying Yan said. In China, summer and autumn are peak seasons for Salmonella infections, with children under 5 years old being more commonly affected. Therefore, attention to food processing hygiene is crucial, and "aseptic eggs" or "clean eggs" can be chosen to further ensure the safety of food for infants and young children.
"Regardless of the region globally, the risk of children under 5 years old being infected with non-typhoidal Salmonella is very high," warned Guo Lingyun. In most cases, children infected with Salmonella may only exhibit mild symptoms of gastroenteritis, which can be treated with antidiarrheal medications, rehydration salts, and probiotics. However, about a quarter of children may experience more severe symptoms, necessitating hospitalization. If very young children, with compromised immune systems, have persistent fever, parents should seek medical attention promptly. In such cases, active antibiotic treatment is recommended. When collecting stool samples, it is important to collect bloody stool samples before antibiotic use. This approach can lead to higher positivity rates in routine stool and stool culture tests.
To prevent Salmonella infections in children, Guo Lingyun advises parents to encourage children to follow the "seven-step handwashing technique," maintain proper hand hygiene, pay attention to food safety and hygiene management, engage in physical activity, and boost their own immune systems.
