"Food is the first priority for the people, and safety is the first priority for food". Food safety is not only related to people's survival and health, but also to the quality and rise and fall of a nation. It also directly affects a country's reputation in international trade exchanges. In recent years, it has attracted worldwide attention and is an important public health problem. But this problem has not attracted the attention of many countries and departments [1]. Due to changes in the natural environment, changes in people's work and lifestyle, globalization and urbanization of food trade, production and utilization of new foods, and natural and man-made factors, food safety is reduced, food-borne diseases and food poisoning occur from time to time, and new food-borne pathogen infections are constantly emerging. No matter in developed or developing countries, food-borne diseases seriously damage human health and have a great impact on the economy. Therefore, food-borne diseases have become one of the most prominent public health problems in the world. Food safety; Foodborne diseases; Prevention and control countermeasures People use a lot of highly toxic pesticides to spray vegetables and fruits in order to get rid of insects. In order to improve the lean meat rate, the banned hormone (lean meat essence) is blindly used to feed pigs; In order to whiten the flour, use sodium bicarbonate at will; In order to cheat money, the rice straw retting water is sold as colored salt soy sauce [2]; This is a long list. With the changes and changes of the times, the expansion and popularization of the scale of food production and operation, and the internationalization of food trade, major food safety incidents have occurred all over the world, such as the "dioxin incident" in Belgium, the "mad cow disease" in Britain, the food poisoning caused by E.coli O 157: H7 in Japan, and the exposure of inferior milk powder, moldy poisoned rice and Sudan red incidents in Fuyang, China, which have made food safety the focus of people's attention. All this also clearly shows that foodborne diseases will not decrease or disappear with the development of economy and the improvement of technical level. No matter in developed or developing countries, food pollution and food-borne diseases have not been effectively controlled, which still seriously endanger people's health and safety. Therefore, it is urgent to control food safety and food-borne diseases. 1 The current situation of food-borne diseases refers to infection or poisoning caused by pathogenic factors that enter the human body through food. Most foodborne diseases are caused by bacteria, viruses, worms and fungi. Epidemiological monitoring data show that in the past 10 years, the incidence of food-borne diseases has been rising all over the world, and a serious epidemic has appeared. It is reported that about 30% people in developed countries suffer from food-borne diseases every year. About 76 million people in the United States suffer from food-borne diseases every year, and about 5,000 of them die. The number of salmonella infections in some European countries has increased five times. Although there is no systematic report of food-borne diseases in developing countries, the problem in developing countries may be more serious. There are many kinds of food-borne diseases in these countries, such as cholera, Campylobacter jejuni, Escherichia coli and Salmonella infection, and the incidence and mortality of diarrhea are high. According to the statistical report of the World Health Organization (WHO), there are hundreds of millions of people suffering from food contamination all over the world, and there are hundreds of millions of cases of diarrhea every year, resulting in the death of about 3 million children under the age of 5, of which about 70% are caused by biologically contaminated food. In developing countries, it is estimated that there are 270 million cases of diarrhea and related diseases every year, resulting in the death of 2.4 million children under 5 years old [2]. At present, only a few countries in the world have established the annual reporting system of food-borne diseases (namely, the United States, Britain, Canada and Japan, among which the monitoring system of food-borne diseases in the United States is the most perfect and the data report is the most complete), and the rate of missing reports is quite high. The rate of missing reports is as high as 90% in developed countries and over 95% in developing countries. Therefore, it is difficult to accurately estimate the global incidence of food-borne diseases. According to the WHO report, the actual number of cases of food-borne diseases is 300 ~ 500 times more than the reported number, and the reported incidence rate is less than 10% of the actual incidence rate. Therefore, the number of reported cases is only the tip of the iceberg. Although China has a sound food poisoning reporting system, there is no sound food-borne disease monitoring system, so it is difficult to estimate the incidence of food-borne diseases. According to the statistics of the Ministry of Health, the number of food poisoning cases, the number of people and the number of deaths in China have increased greatly in recent years. Experts estimate that there are at least 200,000-400,000 cases of food poisoning every year, but the statistical report is about 20,000-40,000 cases, which is still less than the actual110. The food safety situation is not optimistic, and food poisoning incidents occur frequently [2]. In 2002, the Ministry of Health received a total of 128 cases of major food poisoning, with 7 cases of poisoning and 38 cases of death. In 2003, there were 379 major food poisoning incidents, with12,876 people poisoned and 323 people killed, which were higher than those in 2002, respectively, 196.7%, 80.7% and 134. 1%. Although health departments at all levels have taken a series of effective measures to prevent and control food poisoning, actively carried out special rectification of food safety, and severely cracked down on illegal and criminal acts of producing and selling fake and shoddy and toxic and harmful food, and achieved certain results. However, on the whole, all kinds of biological and chemical pollution have not been fundamentally controlled, and food safety and prevention and control of food-borne diseases are still very arduous. Food-borne diseases not only seriously endanger people's health, but also cause huge economic losses. There are about 76 million cases of food-borne diseases in the United States every year, resulting in an economic burden as high as 1, 1000 billion yuan. Australia estimates that the annual economic losses caused by food-borne diseases can reach 2.6 billion Australian dollars. There are about 2.366 million patients in England and Wales every year, and the annual medical expenses and losses are about 300-700 million pounds. 1986 * * The "mad cow disease" that caused global panic slaughtered 1 1 10,000 sick cows, causing economic losses of tens of billions of pounds. 1996 Japanese E.coli O 157: H7 food poisoning incident, which caused more than 9,000 people to be poisoned and caused heavy economic losses. In recent years, China has also caused economic losses of tens of millions of yuan, which has seriously affected the reputation of food enterprises. 2. Factors of food-borne diseases 2. 1 Environmental changes Due to the reform and opening up, a large number of rural people migrated to cities in an unplanned way, resulting in crowded urban population, poor living conditions, heavy pressure on drinking water supply and garbage disposal, and increased opportunities for the spread of food-borne pathogens. With the continuous growth of population, the discharge of agricultural chemicals and industrial wastes is increasing, the organic matter in water is polluted, and heavy metals are enriched in agriculture, livestock and aquatic products, which makes the pollution worse (such as pesticides, fertilizers, growth regulators, veterinary drug residues and persistent organic pollutants pollution). At present, there are 850 rivers, 130 lakes and offshore waters in China, and 5 1 is seriously polluted. These toxic chemicals can enter the human food chain through food, damaging human health and reducing human disease resistance. In 2000, the Ministry of Agriculture tested 2 1 10 samples from 14 economically developed provincial capitals, and the results showed that 23% of the vegetables exceeded the standard. Planting and aquaculture cause source pollution. The annual consumption of nitrogen fertilizer and pesticide in China is 25 million tons and10.3 million tons, respectively, which are three times and two times the world average. Dioxin pollution is another major environmental pollution (burning garbage and automobile exhaust), which directly causes cancer and teratogenesis to meat, milk and aquatic products in secondary pollutants, and the direct lethal dose is 900 times that of arsenic [2]. 2.2 The problem of excessive use and abuse of additives or illegal addition of additives in food production and processing; The production process is not strictly implemented, and the microorganisms are not completely killed; Microbes cause corruption in the process of production, storage and transportation; Food safety problems caused by the application of new raw materials, new technologies and new processes (such as genetically modified irradiated food has aroused widespread concern in academic circles) [2]. These will obviously increase the risk of food-borne diseases. 2.3 Social factors Poverty and backwardness are the main factors causing diseases. Poverty was once called the deadliest disease in the world. Poverty leads to backward food production equipment and knowledge, which will affect the implementation of good food hygiene standards. Although foodborne diseases are common in both the rich and the poor, people in the rich class generally suffer from long-standing mild diseases, while people in the poor group suffer from more serious life-threatening diseases, such as infant diarrhea, cholera, typhoid fever, hepatitis A and other diseases, with higher mortality. 2.4 lifestyle changes lifestyle is closely related to food-borne diseases. Due to the accelerated pace of life, consumers' demand for fast food has increased, and the opportunities for eating out have increased. Dining pays attention to taste, eating fresh is quick, and likes to eat raw food (such as sea cucumber, raw shellfish, fish and shrimp, etc. In addition, some food safety management measures are incomplete and food production is not standardized. These factors increase the risk of food contamination pathogens and food-borne diseases. It has been proved that many fruits and vegetables are carriers of Escherichia coli O 157: H7 and Listeria monocytogenes. The infection caused by these two pathogens is one of the most serious food-borne diseases found in recent years. 2.5 Other factors In addition to the above factors, there are many factors related to the prevalence of food-borne diseases. For example, the internationalization of food trade will lead to the transnational spread of food-borne diseases; Changes in the adaptability of pathogenic microorganisms (Salmonella has developed resistance to various antibiotics, etc. ); New food-borne pathogens are constantly emerging. In recent 20 years, dozens of new pathogens related to food-borne diseases have been found, such as Campylobacter, Escherichia coli 0 157: H7, Listeria monocytogenes, drug-resistant strains of Salmonella, cyclosporine, cyclosporine, prion and so on. Consumers' food safety awareness is weak. Therefore, food safety will face new challenges.