Gastrointestinal food poisoning

　　Gastrointestinal food poisoning is an acute gastrointestinal infection caused by consuming food contaminated by various bacteria. Many bacteria can cause gastrointestinal food poisoning, among which the common ones include:

　　1. Salmonella genus. Salmonella typhimurium, Salmonella enteritidis, Salmonella pullorum, and Salmonella choleraesuis are more common. Such bacteria can be found in the intestines and internal organs of various domestic animals, poultry, fish, birds, rodents, and wild animals. The bacteria are excreted in feces, contaminating drinking water, food, tableware, and are particularly prone to contamination in fresh meat, eggs, and dairy products, leading to infection in humans after consumption.

　　2. Vibrio parahaemolyticus. It is widely present in marine products such as sea fish, shrimp, and crab, as well as salted products such as pickles and cured meats with high salt content. It has strong survival ability, but is extremely sensitive to acid and heat.

　　3. Escherichia coli. Commonly known as E. coli, it is Gram-negative. Most strains have flagella, can move, have pili, and have a capsule. Most strains can ferment lactose, produce acid and gas.

　　4. Proteus. Depending on the biochemical reaction, it can be divided into four types: ordinary, atypical, mucoid, and Pfeiffer's Proteus. The first three can cause food poisoning. This bacterium is widely present in water, soil, decayed organic matter, and the intestines of humans and domestic poultry. It can produce enterotoxins in food and can also produce histidine decarboxylase, causing histidine in proteins to decarboxylate into histamine, thereby causing an allergic reaction. The pathogenic foods are mainly fish and crab, especially the red-belly green-skinned fish. In recent years, there has been a relative increase in the trend of Proteus food poisoning.

　　5. Staphylococcus aureus. Only strains that can produce enterotoxins can cause food poisoning. Staphylococcus aureus is widely present in human skin, upper respiratory tract, nail grooves, etc. Contaminated fish, meat, eggs, starch, and other foods can have a large amount of Staphylococcus aureus reproduction and enterotoxin production when left at room temperature for more than 5 hours. This toxin can withstand boiling for 30 minutes and still retain its toxicity.

　　6. Bacillus cereus. It is widely distributed in soil, dust, rice, flour, milk powder, spices, etc. It can reproduce and produce enterotoxins in large quantities at a suitable temperature.

　　Severe gastrointestinal food poisoning can lead to dehydration, acidosis, and even shock.

　　6. Dehydration: Due to the lesion, a large amount of water is consumed and cannot be replenished in time, causing a symptom of metabolic disorder. In severe cases, it can cause fainting and even life-threatening conditions, requiring intravenous fluid administration to replenish body fluids.

　　5. Acidosis: Severe acidosis may trigger shock, diabetes, uremia, certain renal tubular diseases, and so on.

　　3. Shock: Due to the acute decrease in circulatory function and severe insufficient microcirculation perfusion of tissues and organs, it leads to severe functional and metabolic disorders of vital organs. In the early stage, patients may experience symptoms such as pale skin, cold extremities, increased heart rate and breathing, and reduced urine output; in the middle stage, symptoms such as decreased blood pressure, further cooling of the skin, and cyanosis may appear; if it continues to develop, it can lead to death of the patient.

　　The clinical manifestations are mainly acute gastroenteritis, such as nausea, vomiting, abdominal pain, diarrhea, etc. Staphylococcus aureus food poisoning is characterized by marked vomiting, with vomit containing bile, sometimes with blood and mucus. Abdominal pain is most common in the upper abdomen and around the umbilicus, diarrhea is frequent, mostly yellow loose stools and watery stools. Food poisoning caused by invasive bacteria can lead to fever, episodic severe abdominal pain and mucopurulent stools. Some cases of Vibrio parahaemolyticus food poisoning present with bloodwater-like stools. Type A Clostridium perfringens is less severe, while a few C and F types can cause hemorrhagic necrotizing enteritis. Proteus morganii can also cause facial flushing, headache, urticaria, and other allergic symptoms. Severe diarrhea can lead to dehydration, acidosis, and even shock.

　　The incubation period is short, and cases with an incubation period exceeding 72 hours can basically be excluded as food poisoning. Staphylococcus aureus food poisoning is caused by enterotoxins accumulated in food, with an incubation period of 1 to 6 hours. Clostridium perfringens produces heat-resistant enterotoxins after entering the human body, with an incubation period of 8 to 16 hours. Food poisoning caused by invasive bacteria such as Salmonella, Vibrio parahaemolyticus, and Proteus, among others, usually has an incubation period of 16 to 48 hours.

　　Ensure food hygiene supervision, regularly conduct health checks and health education for kitchen staff, implement the

　　1, Manage the source of infection

　　Upon the occurrence of a suspected food poisoning, report it immediately to the local health and epidemic prevention department, and carry out timely investigations, analyses, and formulate preventive measures to control the epidemic early.

　　Implement the

　　Bacterial culture of the patient's vomit and diarrhea materials and suspected residual food should be performed. Blood culture for severe patients, and collect two serum samples early and two weeks after the disease onset for serum agglutination test with the suspected bacteria isolated from culture. A rising titer of serum agglutination is of diagnostic value. In suspected cases, especially when suspecting bacterial toxin poisoning, animal tests can be performed to detect the presence of bacterial toxins.

　　1, Non-bacterial food poisoning caused by eating germinated potatoes, Xanthium sibiricum, bitter almonds, fugu, or toxic mushrooms, among others, has an incubation period of only a few minutes to several hours. Generally, there is no fever, and the main symptom is repeated vomiting. Abdominal pain and diarrhea are less common, but neurological symptoms are more prominent, with a higher mortality rate. Mercury and arsenic poisoning patients may have sore throat, congestion, and blood in vomit and diarrhea, and the cause can be determined by chemical analysis.

　　2, Cholera and paralytic cholera are characterized by painless diarrhea and vomiting, with vomiting following diarrhea more often, and without fever. Stools appear like rice water. Due to the long incubation period of up to 6 days, outbreaks with a large number of patients in a short period are rare. Diagnosis can be confirmed by finding Vibrio cholerae or V. parahaemolyticus in stool smears stained with fluorescent antibodies and culture.

　　3, Acute bacillary dysentery occasionally presents with food poisoning outbreaks. Vomiting is usually less frequent, and symptoms often include fever, urgent need to defecate, and stools mixed with pus and blood. There is marked tenderness in the lower abdomen and left lower abdomen. Stool microscopy shows red blood cells, pus cells, and macrophages, and approximately half of the stool cultures show growth of Shigella bacteria.

　　4, Viral gastroenteritis is caused by various viruses, characterized by acute enteritis, with an incubation period of 24 to 72 hours. The main symptoms include fever, nausea, vomiting, abdominal distension, abdominal pain, and diarrhea, with watery stools. In severe cases of vomiting and diarrhea, water, electrolyte, and acid-base balance disorders may occur.

　　The patient should rest in bed and have a liquid or semi-liquid diet, which should be light and drink plenty of salt and sugar water.

　　1. Prohibit the consumption of diseased and dead animals and poultry. For those that die due to injury and whose meat quality is good after inspection, the internal organs should be discarded, thoroughly washed, and the meat should be cut into small pieces; the cutting board should be washed and disinfected after use. Do not eat meat that has become moldy, and meat and dairy products should be kept refrigerated (below 6°C) before consumption.

　　2. Meat should be well-cooked, and all utensils that come into contact with cooked food should be washed with running water in advance. The cutting board for raw fish and meat should be cleaned and disinfected before cutting cooked food. Crabs should be fully cooked in boiling water, and if the leftover crabs are stored for more than 6 hours, they should be cooked again before eating. Drunken and pickled crabs cannot kill bacteria, so it is best not to eat them; if necessary, they can be marinated with vinegar to kill bacteria.

　　3. Raw fish, meat, and vegetables should be stored separately. Leftover food, such as rice, vegetables, and congee, should be spread out and stored in a cool and ventilated place to prevent spoilage, and should be thoroughly heated before the next meal.

　　4. When selling food, be sure to separate the goods and money to prevent food contamination.

　　5. Plan the meals according to the number of diners, cook and eat on the spot, and avoid leftovers.

　　6. Eliminate flies, rodents, cockroaches, and mosquitoes, and do not raise domestic animals and poultry near the canteen.

　　The course of this disease is short, and symptomatic treatment should be the main approach.

　　1. General treatment

　　Rest in bed, early diet should be easily digestible liquid or semi-liquid food, and normal diet can be resumed after the condition improves. Food poisoning caused by Salmonella should be isolated at the bedside.

　　2. Symptomatic treatment

　　For patients with obvious vomiting and abdominal pain, they can take atropine (Probenecid) orally or be given atropine subcutaneously, or hyoscyamine can be injected. Those who can eat should be given oral rehydration. For those who cannot eat due to severe vomiting or frequent diarrhea, glucose and saline infusion should be given. In case of acidosis, 5% sodium bicarbonate injection or 11.2% sodium lactate solution should be supplemented according to the situation. For severe dehydration or shock, active fluid replacement should be performed to maintain electrolyte balance and antishock treatment should be given.

　　3. Antimicrobial therapy

　　Generally, it is not necessary to use antibacterial drugs. For severe patients with high fever, antibacterial drugs can be selected according to different pathogenic bacteria. Quinolone antibiotics can be selected for Salmonella and Vibrio parahaemolyticus.