What is Listeria and how does it spread in watermelon?

In summer, everyone likes ice cream. But you can't eat this ice cream!

A few days ago, the US Centers for Disease Control and Prevention announced that the ice cream of an American company, BlueBell, was found to contain Listeria, 8 people were infected and 3 people died. This kind of ice cream has entered the market in China on 20 14 and is sold in many places in China.

This brand of ice cream may be a little strange to Xiamen people, but do you know? Watermelons that everyone loves to see in summer may also be contaminated by Listeria!

Just last week, Mr. Zhan of Xiamen ate a big watermelon that was put in the refrigerator two days ago. Three hours later, he and his wife developed abdominal pain. Half an hour later, my wife didn't get better and vomited. However, Mr. Zhan's abdominal pain intensified, and even dizziness, convulsions, confusion and other symptoms appeared after repeated diarrhea. Subsequently, both of them suffered from severe diarrhea and took turns to "grab" the toilet and stayed up all night.

They were diagnosed with severe food poisoning. Since the beginning of summer, Xiamen Second Hospital has treated several patients with severe food poisoning, and the "real murderer" is probably "Listeria".

This "Listeria" has also attracted the attention of Xiamen CDC. Recently, the center also released a reminder message to remind Xiamen people:

Listeria is very common in life, and it is not afraid of cold. Therefore, when choosing frozen food, we should pay attention to food hygiene and avoid or eat unsterilized food, especially dairy products. At the same time, it is also important to store food correctly.

You may have heard the piano music of Hungarian pianist Liszt, but what the hell is this Listeria? The freezer at MINUS n degrees can't freeze it, and it can even kill people?

Demystifying "Listeria"

Listeria is a facultative anaerobic gram-positive bacterium and one of the most deadly food-borne pathogens. It is more deadly than common salmonella and some Escherichia coli, and the mortality rate is close to 30%.

After eating food containing Listeria, symptoms may not appear immediately, and its "incubation period" can reach 60 to 70 days, so it is easy to be ignored.

Not all people who come into contact with Listeria through food will get sick, but in the sick people, Listeria may bring quite serious or even fatal consequences. Patients with listeriosis usually develop symptoms within 3 -70 days after eating contaminated food, including cold, nausea, vomiting, abdominal cramps, diarrhea, headache, constipation and persistent fever. Sepsis and meningitis may also occur in severe cases of infection.

In addition, Listeria is most likely to affect pregnant women, newborn babies, the elderly and people with low immunity, so these people need to pay special attention to food hygiene and safety. After pregnant women are infected with Listeria, the bacteria can infect the fetus through the placenta, and may cause serious consequences such as abortion, septicemia and neonatal meningitis.

It is ubiquitous in the environment, mainly using food as the vector of infection. In most foods, such as meat, eggs, poultry, seafood, dairy products, vegetables and so on. , has been proved to be the source of listeria infection.

According to the doctor, the ice cream is infected with Listeria monocytogenes, which may be because the condensed water in the production workshop is diffused into the air by the wind, the raw materials are polluted, and the later sterilization is not strict. Listeria can still grow slowly at the cold storage temperature as low as 0℃, which leads to bacteria sneaking into the final product.

One of the characteristics of Listeria is that it likes cold and is afraid of heat, so in fact, your refrigerator is not safe, but it provides an excellent environment for the cross-spread of Listeria and other germs!

Which foods are easily attracted? Monitoring by Xiamen CDC shows that the following foods are at risk of Listeria contamination:

1. Cheese made from raw milk without high temperature sterilization;

2. Sterile mayonnaise;

3. Sandwiches made in advance and stored for a long time;

4. Uncooked bean sprouts;

5. Salad bags bought outside or salads made in advance.

Want to avoid listeria? Please go to the following five points-

1, personal hygiene, you should pay attention to washing your hands before and after handling food, before eating and after going to the toilet.

2. When cooking, keep it clean, separate raw and cooked food, ensure that the food is thoroughly heated, and use safe water and raw materials.

3. In food selection, avoid drinking unsterilized milk or eating unsterilized dairy products.

It should be specially reminded that the refrigerator is not a safe, and Listeria may also breed in the refrigerator.

5. Clean and disinfect the refrigerator regularly, and it is best to fully heat the leftovers and cooked meat products stored in the refrigerator before eating.