Encyclopedia of Family Medicine

Chapter 14 Beware of getting diseases through the mouth (2)
Causes of Bacterial Food Poisoning
Suitable temperature and humidity, as well as abundant nutrients, are necessary conditions for the growth and reproduction of bacteria.In summer, the temperature is above 20°C and the relative humidity is above 70%, which are the suitable conditions for bacterial growth and reproduction.At the same time, when the climate is hot, people often have a significant decline in the defense function of the body due to reasons such as loss of appetite, lack of sleep, and excessive sweating.If you do not pay attention to food hygiene, bacterial food poisoning is prone to occur.In summary, the causes of bacterial food poisoning can be as follows:
(1) Deterioration of raw materials of food.High-protein foods such as fish, meat, eggs, and milk are prone to spoilage, especially in high temperature seasons. If the spoiled fish, meat, eggs, milk and other raw materials are used for food, the heat treatment will not be fully cooked. , Some germs have not been killed, such food is easy to cause poisoning.

(2) The food is not cooked and cooked thoroughly.When processing whole chickens, whole ducks, or large pieces of sauce meat, due to the poor thermal conductivity of meat food, if the heating time is short, the central part of the meat may not be cooked, and the bacteria in the central part will not be killed.For example, if a piece of meat weighing 4 pounds is cooked for 1 hour, the temperature in the center is only 50°C, and the bacteria are still alive.Foods that are not fully cooked in the center are easily spoiled, causing food poisoning.

(3) If the food is stored for too long, even if it is stored in the refrigerator, it is difficult to prevent the contamination and reproduction of bacteria.

(4) Undifferentiated raw and cooked, causing pollution.Raw food often contains a large number of bacteria, and the raw and cooked utensils are not separated, which will cause the cooked food to be contaminated by bacteria.Bacteria multiply to a certain extent, it will cause poisoning.

(5) Eat raw aquatic products, cold dishes, etc.Aquatic products themselves contain a lot of bacteria. If you soak them in boiled water and eat them immediately, the bacteria inside are often still alive. Cold dishes may be poisoned because they are not clean or polluted during processing.

Proteus food poisoning

The genus Proteus is composed of the Proteus family, of which the common, miraculous, and morganic species of Proteus can cause food poisoning.Proteus bacteria widely exist in nature, and Proteus bacteria can be detected in soil, sewage, food, animals and human intestines.Proteus does not cause disease under normal circumstances, but only when people's resistance is low or when the amount of bacteria ingested at one time is very large, they will cause people to get sick.Therefore, it is also called conditional pathogenic bacteria.

There are also a wide range of foods that can cause Proteus poisoning, with meat products being the most common, followed by aquatic products, soy products, and cold dishes.Often due to the high temperature and high humidity in summer, Proteus bacteria on chopping boards, knife blocks, and containers multiply in large numbers, resulting in contamination of various foods.Therefore, after this kind of food poisoning occurs, there is often no single clue of food poisoning.

When a large amount of Proteus is ingested into the human body, the shortest incubation period of only 2 hours can cause the disease.The main symptoms of poisoning are abdominal pain, diarrhea, and vomiting, especially abdominal pain, which sometimes feels like a stabbing pain.Body temperature sometimes rises.The course of the disease is generally 1 to 2 days.

Certain Proteus, such as Proteus morganii, can cause anaphylaxis.Proteus morganii can produce a large amount of histamine (allergen substance) in mackerel and other scombroid fish. After eating this kind of fish contaminated with proteus, it will cause skin flushing, dizziness and headache in a short time , urticaria and a series of allergic symptoms.

salmonella food poisoning

Salmonella spp. are a large family of pathogenic bacteria that can cause illness in animals and humans.Those that can cause food poisoning are mainly typhoid fever, enteritis and Salmonella choleraesuis.

Salmonella was originally the causative agent of salmonellosis in the animal kingdom.When an animal is infected with Salmonella, the bacteria grow and multiply in its gut.Thus causing infectious diseases among animals.Such as swine typhoid, pullorum, swine fever, mouse typhoid and so on.Therefore, sick or dead poultry and livestock often carry a large amount of Salmonella.1% of healthy poultry and livestock also carry salmonella.The bacteria-carrying rate of poultry eggs is 0~5%.During the slaughter of poultry and livestock, especially those that died of disease, a large amount of Salmonella in the intestinal tract of the animal will contaminate the meat.The foods that cause Salmonella food poisoning are mainly meat, meat products, eggs, milk, aquatic products, etc. Among them, the meat of dead livestock is the main cause of Salmonella poisoning in my country.

The incubation period of Salmonella poisoning is generally 12 to 20 hours. The main symptoms of poisoning are nausea, vomiting, abdominal pain, and diarrhea.

To prevent Salmonella poisoning, the most important thing is to strictly prohibit the consumption of dead poultry meat.

Vibrio parahaemolyticus food poisoning

The pathogen that causes Vibrio parahaemolyticus food poisoning is Vibrio parahaemolyticus.Because this vibrio needs to grow in salt-containing conditions, it has been called a halophilic bacteria in the past.Vibrio parahaemolyticus is a marine bacterium mainly carried by inshore marine organisms.The average carrier rate of marine fish and shrimp is 45-6%, and can be as high as 48.7% in summer. The carrier rate of pickled fish and shellfish is 90%, and the carrier rate of pickled vegetables is 42%.Therefore, food that causes Vibrio parahaemolyticus poisoning, in addition to fish, shrimp, crabs and other seafood, meat, pickles, etc., can also cause poisoning after being contaminated by Vibrio parahaemolyticus.Eating sashimi is easy to cause poisoning. When eating sea crabs, it is also easy to be poisoned if it is not heated thoroughly.

After ingesting a large amount of Vibrio parahaemolyticus, the disease will develop after an incubation period of about 10 hours.The body temperature was 37.5~39°C, and there were bursts of colic in the upper abdomen and diarrhea.The stool is like meat washing, sometimes with mucus or pus and blood. In severe cases, the frequency of stool can reach more than 5 times a day, dehydration may occur, and even shock.The course of disease is about 20 week.

staphylococcal enterotoxin food poisoning

Staphylococcus includes three types: lemon, white, and golden yellow, among which Staphylococcus aureus is the most pathogenic.Can cause purulent infection and sepsis.Staphylococcus aureus can produce enterotoxin after 25 hours under high temperature and high humidity conditions, such as 37~5°C.Enterotoxins can poison people.Enterotoxin has strong heat resistance, and its toxicity cannot be destroyed by boiling for 30 minutes. It can be destroyed by heating at 100°C for 2 hours.Therefore, once food is contaminated by Staphylococcus aureus and produces enterotoxin, it is difficult to destroy its toxicity after heat treatment.

Foods that cause enterotoxin poisoning are mainly foods rich in water, sugar, and protein, such as milk, egg products, glutinous rice cakes, and leftover rice.In our country, there are many cases of food poisoning caused by leftover rice in summer.Leftover rice is rich in sugar and water. When it is contaminated by Staphylococcus aureus, under high temperature conditions with poor ventilation, Staphylococcus aureus will multiply and produce enterotoxin.Even if the leftover rice is reheated in the pot before eating, its toxicity will not be destroyed, and it will still cause food poisoning.

The incubation period of enterotoxin poisoning is 2 to 4 hours. The main symptoms are repeated and severe vomiting, and sometimes abdominal pain and heart pain.Usually 1 to 2 days to recover.

Clostridium botulinum toxin food poisoning
Clostridium botulinum toxin food poisoning, referred to as botulism.Botulism is worldwide and occurs more frequently in the northern hemisphere of the earth and around 30° north latitude, that is, parts of North America, Europe, China and Japan.The incidence is higher in the northwest regions of my country, especially in Xinjiang.The fatality rate of botulism is 40-60%, ranking first in bacterial food poisoning.

肉毒中毒是由肉毒梭状芽胞杆菌产生的毒素引起的。肉毒毒素的毒性极强，0.01~0．0084毫克的肉毒毒素就可以使人致死。该毒素耐酸，不耐碱，不耐热。80℃加热30分钟或100℃加热10~20分钟，就可以完全被破坏。

91.5% of botulism in our country is caused by plant food.Mainly homemade fermented food.Such as stinky tofu, tempeh, bean paste and "rice send huhu".The main reason is that the beans are polluted by Clostridium botulinum in the soil, the heating is impermeable during the processing, and the spores are not killed. Clostridium bacteria multiply and produce toxins.Fermented food is poisoned if it is not reheated before eating.Vegetables, fruits, and canned meat can also cause botulism if the heating is impermeable during processing and the Bacillus is not eliminated.

The incubation period of botulism is as short as 6 hours, generally 1 to 4 days.The initial symptoms were malaise, dizziness, and unsteady walking. A few people had symptoms of vomiting, abdominal pain, and diarrhea.Then obvious symptoms of neurotoxicity appeared, such as drooping eyelids, diplopia, mydriasis, hoarse voice, dry mouth, difficulty swallowing, and drooping head.In severe cases, respiratory paralysis, until death.

Bacillus cereus food poisoning
Bacillus cereus food poisoning is caused by the bacteria Bacillus cereus.Bacillus cereus is widely present in soil, dust, rotting grass and air in nature.Food is also easily contaminated by Bacillus cereus during processing, transportation, preservation and sales.Meat, milk, rice, vegetables, and fruits carry bacteria at a rate of 20-70%.Bacillus cereus does not reproduce below 15°C, but can grow and develop at normal room temperature. The most suitable temperature is 32~37°C. The reproductive type is not heat-resistant, and can be killed after 100 minutes at 20°C. The spore type is heat-resistant .

Cooked food, such as rice, cooked meat, and dairy products, is placed at a temperature above 20°C for a long time, and Bacillus cereus will produce a large amount of toxins.When people ingest Bacillus cereus with more than 100 million bacteria per gram of food, it will cause poisoning.

Different Bacillus cereus produce two different enterotoxins, vomit-type and diarrhea-type enterotoxins.The incubation period of vomiting-type poisoning is 0 to 5 hours, and it can be as long as 2 to 5 hours.The main symptoms are nausea, vomiting, dry mouth, abdominal pain, etc. A few people have diarrhea, the body temperature is generally not high, and the course of the disease is about 6 day.For diarrhea-type poisoning, the incubation period is slightly longer, with an average of 1 to 10 hours. The symptoms are mainly abdominal pain and diarrhea, and occasional vomiting and fever. The course of the disease is also one day.

Ways to Prevent Bacterial Food Poisoning
In recent years, with the improvement of living conditions and the introduction of refrigerators into households, especially in big cities, the incidence of bacterial food poisoning has been declining.However, food poisoning is still a frequently-occurring disease in summer, and even in developed countries, it has not been completely eliminated.If you are not careful, food poisoning will cause damage to the health of many people.Therefore, it is very necessary to pay attention to food hygiene and actively prevent food poisoning.

(1) When processing food, first of all, the raw materials should be strictly controlled.Any spoiled raw materials shall not be used for processed food.The food in the refrigerator should be checked and cleaned regularly; the refrigerator should also be cleaned frequently to keep it clean and odorless to reduce the contamination of the food.

(2) When processing food, it must be cooked thoroughly.It is best to cook and eat now, and the remaining food should be kept in a refrigerated or ventilated place.Overnight food should be returned to the pot and reheated thoroughly before eating.

(3) Keep cooking utensils hygienic and strictly separate raw and cooked.Cooking utensils should be cleaned and sterilized every meal; utensils for holding and processing raw and cooked food should be used separately to avoid crossover to prevent contamination of cooked food.

(4) When eating cold dishes raw, they must be cleaned, and it is better to soak them in disinfectant or scald them with boiling water, which is safer.

(5) Operators who prepare food should pay special attention to personal hygiene.Nails should be cut short. After urinating and urinating, hands must be washed with soap and running water before operation; when handling cooked food directly with hands, hands should be disinfected.During the food preparation process, do not scratch the skin or nostrils to prevent bacteria from contaminating the food.

Moldy sugarcane poisoning
Mildew of sugarcane is mainly caused by the proliferation of mold after long-term storage under unfavorable conditions.Eating moldy sugarcane can cause poisoning.The mildewed sugarcane poisoning in the north mostly occurred in February to April, and the incidence was mostly in children.

The moldy sugarcane is soft, the pulp is darker than normal sugarcane, light brown, and has a mild musty smell.The main fungus isolated from moldy sugarcane was Arthrospora.The toxin produced by Arthromyces is poisonous to humans.

The incubation period of moldy sugarcane poisoning is short, ranging from just over 10 minutes to over 10 hours.The toxin mainly invades the central nervous system.The characteristic symptom is a biased gaze of the eyeballs.The limbs twitched, and the hands were like chicken feet.At the same time, there may be vomiting and incontinence.Even coma.Body temperature is generally normal.Severe neurological sequelae can be left behind.When the toxin seriously violates the central nervous system, it can die of respiratory failure.

Prevention of moldy sugarcane poisoning: Sugarcane must be harvested after maturity to prevent unripe sugarcane from containing less sugar and prone to mildew.The harvested sugarcane should be protected from freezing; the storage time in winter should not be too long to prevent mildew.Once moldy sugarcane occurs, it is forbidden to sell and eat to prevent poisoning.

Scab wheat food poisoning
Wheat scab is a fungal disease that affects crops such as wheat, barley, corn, and rice.Fusarium head disease not only reduces the yield of crops, but at the same time, people and animals can cause Fusarium head disease wheat poisoning after eating the grains with head disease by mistake.The poisoning mostly occurs in rural areas.

After ingesting scab wheat, within 10 to 30 minutes, nausea, vomiting, dizziness, abdominal pain, general weakness, and a few people have diarrhea, drooling, facial flushing, etc.The vomiting is obvious, which lasts for about 2 hours, and the symptoms disappear on their own.In severe poisoning, fluctuations in respiration, pulse, body temperature and blood pressure may occur, but no deaths have been reported.Using scab wheat as feed can cause poisoning in horses, pigs, dogs and other livestock, but there is no poisoning in sheep, cattle, adult chickens and ducks.

The prevention of head blight wheat poisoning mainly requires good field management of crops, selection of varieties resistant to head blight, deep plowing can reduce the occurrence of head blight, and when necessary, use high-efficiency, low toxicity, and low residue fungicides. After that, it should be threshed and dried in time, and the grain warehouse should be ventilated to prevent grain mildew.

When mildewed grains have been found, the mildewed grains can be removed, or the grains can be removed by soaking in water or lime water to remove the grain shell and ground into fine powder, which can also greatly remove its toxicity.

puffer fish poisoning

Puffer fish are poisonous fish.Tetrodotoxin in fish can poison humans.Tetrodotoxin is mostly distributed in the ovary and liver of fish, followed by kidney, blood, eyes and skin.In spring, the ovary of puffer fish is in the late stage of development, and its ovary and liver are the most toxic.The lower reaches of the Yangtze River are prolific in puffer fish, which is a high-incidence area for puffer fish poisoning.

Tetrodotoxin is a non-protein neurotoxin that is highly toxic and heat-resistant.After the puffer fish is cooked, its toxicity cannot be destroyed.

After eating puffer fish by mistake, the incubation period of poisoning is generally about 10 minutes, and can be as long as 3 hours.Symptoms of poisoning include: stabbing pain in fingers, lips and tongue at first, then nausea, vomiting, diarrhea and other gastrointestinal symptoms, followed by fingertip numbness.In severe cases, limb muscle paralysis, general paralysis, blood pressure and body temperature drop, dyspnea, and most of them died of respiratory and heart and kidney failure.

(End of this chapter)