Vibrio and Salmonella are the top bacterial pathogens linked to outbreaks in catering facilities, according to a decade of data from incidents in China.

From 2010 to 2020, China’s catering service facilities reported 18,331 outbreaks, which resulted in 206,718 illnesses, 68,561 hospitalizations, and 201 deaths.

There were 5,607 outbreaks in restaurants, 2,876 outbreaks from street vendors, and 2,560 in employee canteens. Rural banquets and street vendors were associated with 64 and 34 deaths, respectively. Data comes from the Foodborne Disease Outbreak Surveillance System (FDOSS).

The median number of patients per outbreak was 15, with a median of three hospitalizations per event, according to the study published in the journal China CDC Weekly.

Past research has shown that inadequate time-temperature control, poor kitchen hygiene, and the presence of infected food handlers in catering facilities, contribute to foodborne illnesses.

Agent behind incidents
The number of outbreaks and cases climbed rapidly from 2010 to 2018, with a peak of 3,610 outbreaks and 31,230 cases in 2018. A decrease in 2020 could be related to the COVID-19 pandemic and control measures, found the study.

Pathogenic microorganisms were the primary cause of outbreaks in southern, northwestern, eastern, central, and northern regions of China, while toxic animals, plants, and poisonous mushrooms were the leading cause in northeastern and southwestern regions.

Chemical-related incidents resulted in the most fatalities in the northeastern, northwestern, central, and northern regions. While toxic animals and plants were the leading cause of deaths in southern and eastern regions. Poisonous mushrooms accounted for the highest fatality rates in the southwestern region. 

Pathogens accounted for 4,883 outbreaks, 94,047 cases, 32,170 hospitalizations, and 21 deaths. Toxic animals, plants, and mushrooms were responsible for 3,279 outbreaks, 30,698 cases, 12,338 hospitalizations, and 95 deaths. The cause was unknown for more than 18,500 outbreaks with 21 deaths.

Chemical substances, such as methanol and nitrite, caused 63 fatalities. Vibrio parahaemolyticus, Salmonella, and Staphylococcus aureus were the most prevalent pathogens, resulting in 3,333 outbreaks, 60,520 cases, 21,491 hospitalizations, and nine deaths.

Meat products, aquatic goods, and vegetables were associated with 2,724, 1,595, and 1,571 outbreaks, respectively, between 2010 and 2020.

Outbreaks by cause

The main causes of outbreaks in restaurants were incorrect processing, accidental ingestion, and cross-contamination. The primary causes in street vendors were accidental ingestion, improper storage, and inadequate processing. Staff canteens had outbreaks mainly due to undercooking, accidental ingestion, and improper processing.

Despite the presence of food safety management systems in many restaurants and cafeterias, implementation was not always effective, said researchers. Control measures include public health education on foodborne diseases at these sites and regular food safety training for restaurant employees and managers.

Aquatic products contaminated with Vibrio parahaemolyticus at restaurants and rural banquets, as well as lectins in red kidney beans in staff canteens, were the primary contributors to outbreaks in catering operations.

“Due to shifts in dietary patterns and the fast-paced nature of modern life, an increasing number of individuals have opted to dine at foodservice establishments in recent years. It has been documented that a variety of food safety risks exist in foodservice facilities, such as restaurants, including those associated with food ingredients, handling practices, storage, and transportation. These risks may contribute to the occurrence of foodborne disease outbreaks.”