Epidemiology of Staphylococcus aureus

Staphylococcus aureus is ubiquitous in nature It can be found in air, water, dust and human and animal waste As a common pathogen of human and animals, Staphylococcus aureus mainly exists in the nasal cavity, throat and hair of human and animals, and more than 50% of healthy people's skin As a result, there are many opportunities for food contamination In recent years, the U.S Centers for Disease Control reported that Staphylococcus aureus was the second leading cause of infection, second only to Escherichia coli The epidemiology of Staphylococcus aureus generally has the following characteristics: seasonal distribution, mostly seen in spring and summer; there are many kinds of toxic food, such as milk, meat, eggs, fish and their products In addition, poisoning events caused by leftovers, fried eggs, glutinous rice cakes and cold noodles have also been reported The rate of bacteria in nasal cavity of patients with upper respiratory tract infection is 83%, so the site of suppurative infection of human and animal often becomes the source of pollution In general, Staphylococcus aureus can contaminate food through the following ways: Food processing personnel, cooks or sales personnel carry bacteria, causing food pollution; food carries bacteria before processing, or is contaminated during processing, producing enterotoxin, causing food poisoning; cooked food products are not packed tightly, and the transportation process is polluted; cows suffer from suppurative mastitis or local suppuration of livestock, causing pollution to other parts of the body Staphylococcus aureus enterotoxin is a world health problem In the United States, the food poisoning caused by Staphylococcus aureus enterotoxin accounts for 33% of the total bacterial food poisoning, while in Canada, it accounts for more, accounting for 45% There are many such poisoning events in China every year The formation conditions of enterotoxin: the higher the storage temperature is at 37 ° C, the shorter the time of producing enterotoxin; the place of storage, the lower the pressure of poor ventilation oxygen, the easier the formation of enterotoxin; the type of food, rich in protein, water, and a certain amount of starch, the easier the formation of enterotoxin.