Brief introduction of Listeria monocytogenes
Second, people infected with Listeria.
3. Foods susceptible to Listeria infection
Fourth, the clinical manifestations of Listeria
Verb (abbreviation of verb) Prevention of Listeria infection
Brief introduction of Listeria monocytogenes
According to ABC local time 10, the Centers for Disease Control and Prevention (CDC) announced that it would investigate listeria infections reported in six different states. At present, 16 people have been infected with listeria, and 1 person has died. It is reported that at least 13 people were hospitalized due to listeria infection, and one pregnant woman had a miscarriage due to the disease. In addition, Maryland also reported 1 death.
Listeria is ubiquitous in nature and is not easy to be killed by environmental factors such as freezing and thawing and strong light. This kind of bacteria exists in soil, rotten vegetables, sewage, rivers, waterways and feed, so it is often carried by people and animals. Contaminated animal food, such as milk, chicken and frozen food, can lead to the outbreak of infectious diseases.
Listeria infection can cause human meningitis, septicemia, abortion, neonatal infection and other diseases. If an immunocompromised person is infected with Listeria, the condition is serious and the mortality rate is as high as 33%. It can be seen that Listeria is still very dangerous, not only common in life, but also has a high mortality rate, so it is very important to prevent Listeria.
Listeria is an intracellular parasite, which does not produce endotoxin, but can produce hemolytic exotoxin. T cells play an important role in eliminating this kind of bacteria, and people with low cellular immune function and immunosuppressants are more susceptible to infection. Bacteria can directly affect placenta, amniotic fluid, uterine cavity or fetus, resulting in stillbirth, premature delivery or neonatal infection. Bacteria can often be isolated from the infected site, and the density of bacteria in the gastrointestinal tract and lungs of infants is the highest, suggesting that the infection is caused by inhalation of amniotic fluid, not blood-borne. Direct contact between veterinarians and laboratory personnel can lead to skin and eye infections. Bacteria can form disseminated small abscess or miliary granuloma formed by macrophages in brain, meninges, lungs, liver, spleen and other organs.
Second, people infected with Listeria.
From the introduction of Listeria, we can know that Listeria infection is very dangerous, so let's see who is more susceptible to Listeria infection in life.
1, drugs
Long-term use of broad-spectrum antibiotics, a large number of immunosuppressants and a large number of estrogen treatments lead to low immunity and listeria infection.
2. Age
The most common thing is that the resistance of the elderly over 65 years old decreases, which leads to easy infection. With the increase of age, the ability of the immune system and organs of the elderly to identify and eliminate harmful bacteria in the body is weakened.
3. Influence
Listeria is an intracellular parasite, which does not produce toxin, but can produce a hemolytic exotoxin. T cells play an important role in eliminating this kind of bacteria. The number of megakaryocytes in patients infected by bacteria or fungi increases, which provides conditions for the survival of Listeria and the production of toxins. Patients may have overlapping infection or cross infection.
To sum up, people with low immunity are more likely to be infected with Listeria. Generally speaking, the elderly, pregnant women, newborns and patients with chronic diseases have relatively low immunity, and they are all high-risk groups of listeria infection.
3. Foods susceptible to Listeria infection
In addition to understanding the people who are easily infected with Listeria, let's learn about some foods that are more susceptible to Listeria. These foods lead people to eat these foods contaminated with Listeria, thus infecting Listeria.
1, cooked meat
Roast chicken, pig's head, ham sausage and roast duck bought in outside stores will breed Listeria if stored at room temperature for a long time and improperly, thus inducing infection.
Step 2: salad
Vegetable salad or fruit salad, vegetables and fruits are not thoroughly cleaned or peeled, then Listeria will follow the food into the body, and a certain amount can induce diseases.
3.ice cream
In hot weather, almost every household has ice cream or ice cream in the refrigerator. If you don't finish eating, you can put it directly in the refrigerator to continue refrigeration. However, if raw food and cooked food are not separated in the refrigerator, Listeria will breed, and the opened ice cream or ice cream will be contaminated by Listeria.
In other words, frozen and long-term stored foods are more susceptible to Listeria infection, so people who eat cold food and food in the refrigerator for a long time are more likely to eat the virus infected with Listeria.
Fourth, the clinical manifestations of Listeria
Most infections are temporary after infection. Children's dominant infection is mainly characterized by meningitis and septicemia, while adult infection is characterized by various organ parenchymal lesions.
1, pregnancy infection
Due to the decline of cellular immune function of pregnant women, they are easy to be infected with this bacterium, and symptoms similar to upper respiratory tract infection such as chills, fever, headache and myalgia appear. Most of them are 26 ~ 30 weeks pregnant. If the symptoms are self-limited, it will not affect the fetus, but it will also lead to premature birth, stillbirth or neonatal meningitis and death. If accompanied by amnionitis, pregnant women can continue to have fever, but there will be no habitual abortion after infection.
2. Neonatal infection?
Newborns are infected in the fetal period and get sick after delivery. Characterized by disseminated abscess or granuloma of liver, spleen, lung, kidney and brain. Sepsis is common in the early stage, and neonatal meningitis occurs in the late stage two weeks after full-term delivery. Often accompanied by conjunctivitis, pharyngitis, red papules on the skin of trunk and limbs. Children may have respiratory or circulatory failure, and the mortality rate is as high as 33 ~ 100%. Early treatment can improve the survival rate.
3. Central nervous system infection?
Characterized by meningoencephalitis or brainstem encephalitis. This bacterium ranks fifth among common pathogens and third among community-acquired meningoencephalitis. It is the most common pathogen of meningoencephalitis caused by lymphoma, organ transplantation or hormone users. Typical manifestations are fever, headache, nausea, vomiting, meningeal irritation, ataxia, etc. And there are very few coma. All patients with brainstem encephalitis are adults, and the incidence rate is low. But the brain may have asymmetric hemiplegia and ataxia. About 40% of patients have respiratory failure and the mortality rate is high.
4. endocarditis?
More common in adults, patients may have basic diseases such as heart valve disease or cancer. 7.5% of bacteria are infected with endocarditis, accompanied by septicemia, and the mortality rate can be as high as 48%.
5. Local infection?
The purulent conjunctivitis and skin infection caused by this bacterium may be part of infantile septicemia granuloma. Lymph node infection is more common in the neck and can be mixed with tuberculous lymph node infection.
6. Gastrointestinal infection?
It is a kind of self-limited febrile gastroenteritis, which is characterized by diarrhea, nausea, vomiting, fever and other symptoms.
In addition, this bacteria can also cause hepatitis, liver abscess, cholecystitis, spleen abscess, arthritis, osteomyelitis, myelitis, brain abscess, endophthalmitis and so on.
Verb (abbreviation of verb) Prevention of Listeria infection
Knowing so many dangers of Listeria, it is more important to learn to prevent Listeria infection, take preventive measures in life, try to avoid contact with Listeria and prevent food from carrying Listeria. Then let's see how to prevent listeria infection.
1, the food is thoroughly cooked.
Listeria is particularly afraid of high temperature. Generally above 70℃, continuous heating for 5 minutes can kill all Listeria. So the food you eat every day should be thoroughly cooked, especially poultry, livestock, seafood and eggs. Leftovers and cooked food should also be thoroughly heated before eating, which can kill most microorganisms.
2. Separate raw food from cooked food.
First understand what is raw food and cooked food, the former is unprocessed food, such as raw meat and seafood; The latter is cooked food and heated food. The two foods must be stored separately, and special tableware should be installed as far as possible.
Step 3 store food correctly
Understand the storage conditions of each food and how long it can be stored to avoid breeding too many bacteria. Unsealed food should be packed in a fresh-keeping box and then stored in the refrigerator. Meat frozen in the refrigerator should not be frozen repeatedly. The correct way is to cut it into several pieces of equal size and put it in a packaging bag for storage, one bag at a time.
Step 4 pay attention to cleaning
When cooking ingredients, you must ensure that the raw materials are fresh and hygienic, wash your hands thoroughly, and thoroughly clean the knives and chopping boards. At the same time, we should pay attention to the cleanliness of the refrigerator. Listeria can't be killed even at low temperature. So clean the refrigerator every 1~2 months. The correct way to clean the refrigerator is to cut off the power supply, clean it with hot water and detergent, and then rinse it with clean water.
Step 5 strengthen exercise
Strengthen exercise, do some exercise every day, or take more walks. Keep a good habit of work and rest and improve immunity.
Listeria is very harmful to human body, and may even cause death. To effectively prevent listeria infection, we should put food safety in the first place, especially pay attention to the hygiene and cleanliness of refrigerators. In addition, when buying food, you should know its shelf life and control the freezing and cold storage temperature, no matter which food is stored for too long; After opening the food package, it needs to be heated thoroughly; People with low immunity try not to eat leftovers. At the same time, improving immunity is the most effective way to prevent listeria infection. It is necessary to strengthen exercise, maintain good eating habits and work and rest habits, and improve immunity.