Salmonella Detected in Consecutive Food Poisoning Incidents: Possible Causes and Prevention Highlights
Professor Yen Tsung-hai of Chang Gung Hospital and public health specialist Tsai Ping-chien point out that Salmonella is widespread in animal populations, with groups B and D being the most common causes of food safety issues in Taiwan. Salmonella group D is strongly linked to poultry eggs, and insufficient heating or improper storage can lead to mass poisoning. Symptoms include diarrhea, abdominal pain, and fever, with a risk of sepsis for the elderly and infants. Prevention emphasizes handwashing, fresh ingredients, separating raw and cooked foods, thorough cooking, and proper storage.
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- 📰 Published: April 10, 2026 at 18:44
- 🔍 Collected: April 10, 2026 at 19:00 (16 min after Published)
- 🤖 AI Analyzed: April 15, 2026 at 21:52 (122h 52m after Collected)
Salmonella is widely present in the animal kingdom. Yen Tsung-hai, a professor-level attending physician in the nephrology department at Chang Gung Hospital and a food safety expert, told CNA today that there are over 2500 serotypes of Salmonella, among which groups B and D are the most likely to cause food safety problems in Taiwan. Common contaminated foods include eggs, meat, and soy products.
Public health specialist Tsai Ping-chien explained that Salmonella group D is highly associated with "poultry eggs," with Salmonella enteritidis serotype being the most common. It can enter the egg interior from the hen's ovary before the eggshell forms, meaning that even if the eggshell is intact and washed, the egg interior may still carry bacteria. Therefore, if egg threads in spring rolls, braised eggs in cafeterias, or soft-boiled eggs are not heated above 75 degrees Celsius, they are highly likely to cause mass poisoning.
According to information from the Ministry of Health and Welfare's Food and Drug Administration, after ingesting Salmonella, symptoms typically appear within 4 to 48 hours (average of about 24 hours). The shorter the onset time, the more severe the symptoms. Main symptoms include diarrhea, abdominal pain, chills, fever (high fever maintained at 38 to 40℃), nausea, and vomiting. Symptoms usually last 2 to 3 days before recovery, but 5% of individuals may become carriers.
Yen Tsung-hai warned that Salmonella infection can be very serious. While most people experience acute gastroenteritis, the elderly, infants, pregnant women, and immunocompromised individuals may develop sepsis, bacteremia, and risk organ failure.
Liu Chung-han, a founding member of the Chinese Association of Food Technologists, pointed out that large-scale food poisoning cases are more common in school lunch programs or military mass catering, and less common in restaurant settings. The recent two cases both occurred with mixed ready-to-eat foods that had not undergone complete processing, packaging, and quality control, characterized by needing to be consumed immediately and not stored for later meals.
Tsai Ping-chien analyzed that Salmonella reproduces extremely quickly between 20 and 40 degrees Celsius. Coupled with the rising temperatures and increased humidity in Taiwan in April, if kitchen environments do not strictly control temperatures, such as leaving ingredients at room temperature for too long, bacterial counts will grow exponentially.
Furthermore, due to the surge in demand for "spring rolls" during the Qingming Festival, Tsai Ping-chien said that to rush production, businesses might prepare large quantities of side dishes in advance. If storage space is insufficient, leading to slow cooling, ingredients could fall into the dangerous temperature zone for bacterial growth.
Tsai Ping-chien said that in addition to inspecting various ingredients, health authorities should also sample high-frequency contact surfaces in kitchens, such as knife handles, cutting board crevices, rags, and refrigerator handles, to clarify whether bacteria were "introduced with ingredients" or due to "environmental cross-contamination."
Moreover, since Salmonella can be transmitted via the fecal-oral route, Tsai Ping-chien pointed out that if an employee is an asymptomatic carrier with poor hand hygiene, they will become a continuous source of contamination. Therefore, all food handlers should undergo fecal screening.
Regarding whether it could be due to bacterial mutation, Tsai Ping-chien indicated that the possibility is low, as bacteria are less prone to mutation than viruses.
Tsai Ping-chien highlighted five key points for meal preparation: wash hands, use fresh ingredients, separate raw and cooked foods, cook thoroughly, and pay attention to ingredient storage. It is worth noting that hot food should be kept above 60 degrees Celsius to inhibit bacterial growth. The range between 7 and 60 degrees Celsius is where bacteria grow most rapidly, and food should be kept in this temperature range for as short a time as possible.
Liu Chung-han stated that although health agencies conduct large-scale sampling of seasonal foods during festive periods, some may still be missed. Food service operators can seek professional assistance from public health specialists and food technologists to strengthen food safety controls and protect public health. (Editor: Lung Po-an) 1150410
Public health specialist Tsai Ping-chien explained that Salmonella group D is highly associated with "poultry eggs," with Salmonella enteritidis serotype being the most common. It can enter the egg interior from the hen's ovary before the eggshell forms, meaning that even if the eggshell is intact and washed, the egg interior may still carry bacteria. Therefore, if egg threads in spring rolls, braised eggs in cafeterias, or soft-boiled eggs are not heated above 75 degrees Celsius, they are highly likely to cause mass poisoning.
According to information from the Ministry of Health and Welfare's Food and Drug Administration, after ingesting Salmonella, symptoms typically appear within 4 to 48 hours (average of about 24 hours). The shorter the onset time, the more severe the symptoms. Main symptoms include diarrhea, abdominal pain, chills, fever (high fever maintained at 38 to 40℃), nausea, and vomiting. Symptoms usually last 2 to 3 days before recovery, but 5% of individuals may become carriers.
Yen Tsung-hai warned that Salmonella infection can be very serious. While most people experience acute gastroenteritis, the elderly, infants, pregnant women, and immunocompromised individuals may develop sepsis, bacteremia, and risk organ failure.
Liu Chung-han, a founding member of the Chinese Association of Food Technologists, pointed out that large-scale food poisoning cases are more common in school lunch programs or military mass catering, and less common in restaurant settings. The recent two cases both occurred with mixed ready-to-eat foods that had not undergone complete processing, packaging, and quality control, characterized by needing to be consumed immediately and not stored for later meals.
Tsai Ping-chien analyzed that Salmonella reproduces extremely quickly between 20 and 40 degrees Celsius. Coupled with the rising temperatures and increased humidity in Taiwan in April, if kitchen environments do not strictly control temperatures, such as leaving ingredients at room temperature for too long, bacterial counts will grow exponentially.
Furthermore, due to the surge in demand for "spring rolls" during the Qingming Festival, Tsai Ping-chien said that to rush production, businesses might prepare large quantities of side dishes in advance. If storage space is insufficient, leading to slow cooling, ingredients could fall into the dangerous temperature zone for bacterial growth.
Tsai Ping-chien said that in addition to inspecting various ingredients, health authorities should also sample high-frequency contact surfaces in kitchens, such as knife handles, cutting board crevices, rags, and refrigerator handles, to clarify whether bacteria were "introduced with ingredients" or due to "environmental cross-contamination."
Moreover, since Salmonella can be transmitted via the fecal-oral route, Tsai Ping-chien pointed out that if an employee is an asymptomatic carrier with poor hand hygiene, they will become a continuous source of contamination. Therefore, all food handlers should undergo fecal screening.
Regarding whether it could be due to bacterial mutation, Tsai Ping-chien indicated that the possibility is low, as bacteria are less prone to mutation than viruses.
Tsai Ping-chien highlighted five key points for meal preparation: wash hands, use fresh ingredients, separate raw and cooked foods, cook thoroughly, and pay attention to ingredient storage. It is worth noting that hot food should be kept above 60 degrees Celsius to inhibit bacterial growth. The range between 7 and 60 degrees Celsius is where bacteria grow most rapidly, and food should be kept in this temperature range for as short a time as possible.
Liu Chung-han stated that although health agencies conduct large-scale sampling of seasonal foods during festive periods, some may still be missed. Food service operators can seek professional assistance from public health specialists and food technologists to strengthen food safety controls and protect public health. (Editor: Lung Po-an) 1150410