OVERVIEW
由病毒感染引起的急性胃肠道疾病
主要症状有恶心、呕吐、发热、水样便、腹痛等
主要由轮状病毒、诺如病毒以及腺病毒等引起感染
无特效治疗，可根据病情采取对症治疗等综合治疗方式
Definition
Viral gastroenteritis is an acute gastrointestinal infection caused by various viral infections. Common pathogens that cause this disease include rotavirus, norovirus, astrovirus, adenovirus, and so on.
The disease is contagious, and patients often have a series of symptoms such as nausea, vomiting, abdominal pain, diarrhea, and fever.
Classification
It is mainly categorized according to the type of virus [1].
Rotavirus gastroenteritis
The rotavirus genome consists of 11 segments of double-stranded RNA, with three layers of icosahedral protein capsids, no envelope, spherical shape, diameter of about 75 nm. rotaviruses are relatively stable in the external environment, acid-resistant, and are not easily damaged by gastric acid, and they can survive up to 7 months at room temperature.
Rotavirus mainly invades the duodenum and the jejunum, and multiplies in the epithelial cells of the intestinal mucosa, which results in cell deformation and even necrosis, causing the small intestine to lose the function of digesting and absorbing lactose and sucrose.
In addition, the sugar is retained in the intestinal lumen, causing a further increase in the osmotic pressure of the intestinal lumen, which leads to a large amount of liquid into the intestinal tract, resulting in the occurrence of diarrhea and vomiting.
Noroviral Gastroenteritis
Norovirus is 27~40nm in diameter, a tiny, non-enveloped circular, icosahedral virus, the viral genome is a single-stranded positive-stranded RNA, which has strong resistance to various physical and chemical factors.
The virus can replicate in the cell nucleus. As a result of changes in the enzymatic activity of epithelial cells, it causes impaired absorption of lipids as well as sugars, which in turn leads to increased osmotic pressure in the intestinal lumen and entry of fluids into the intestinal tract, leading to symptoms of nausea and vomiting.
Adenovirus gastroenteritis
Adenovirus is a double-stranded DNA with a diameter of 70~80nm, which accounts for 2%~12% of the causes of diarrhea in young children. children under 5 years old are susceptible to the disease, especially those under 2 years old. After the disease can get longer immunity, epidemic seasonality is not obvious.
It is mostly due to increased osmotic pressure in the intestinal lumen causing nausea, vomiting and other symptoms.
Astrovirus gastroenteritis
The surface of astrovirus has 5~6 protrusions in the form of asterisks, and the size of virus particles is inconsistent, with an average diameter of 28 nm±0.5 nm. It contains single-stranded positive-stranded RNA, 3 open reading frames, and 5 serotypes. Can grow in human embryonic kidney cells.
The incubation period of astrovirus gastroenteritis is 3-4 days, and adults have milder symptoms than infants; in addition to diarrhea, some patients have vomiting and low-grade fever. The detection of astrovirus by electron microscopy in feces has diagnostic and differential diagnostic significance.
Morbidity
Distribution of disease
Rotaviral gastroenteritis is prevalent in infants and young children between 6 and 24 months of age [1].
Noroviral gastroenteritis occurs in the elderly as well as in children.
Adenoviral gastroenteritis occurs in infants and children between 9 and 12 months of age.
Astroviral gastroenteritis is prevalent in children below 7 years of age as well as in the elderly population.
Incidence
The incidence of common viral gastroenteritis is unknown because epidemiologic studies of viral gastroenteritis are lacking.
The disease is somewhat self-limiting. Patients gradually improve with aggressive treatment.
Causes
Causes
Viral gastroenteritis is caused by acute viral infection.
Source of infection: Commonly associated viruses include rotavirus, norovirus, astrovirus, and adenovirus.
Transmission: Through fecal-oral transmission, respiratory transmission, and direct human-to-human contact, the virus can enter the body and cause acute gastrointestinal infections.
Susceptible groups: Infants, young children, the elderly and other people with low immunity are susceptible to infection.
Triggering factors
The following factors can trigger the above mentioned causes, causing the onset or aggravation of viral gastroenteritis.
Unclean diet
Not paying attention to dietary hygiene and eating unclean food can trigger or aggravate the symptoms of viral gastroenteritis.
Unhygienic eating habits
Failure to wash hands before meals and pay attention to tableware hygiene can trigger the development of this disease.
Low immunity
Some people with low immunity, such as the elderly, infants and young children, have reduced immunity against external viruses and are susceptible to the disease.
Risk factors
People with any of the following risk factors are susceptible to viral gastroenteritis.
Elderly people.
Infants and young children.
Long-term use of glucocorticoids or other medications.
People with chronic diseases such as diabetes, hypertension, heart failure, etc.
People suffering from leukemia, malignant tumors, etc.
Symptoms
Main Symptoms
Nausea and vomiting
Nausea and vomiting are one of the main symptoms in patients with viral gastroenteritis and can occur in most patients.
It is mainly related to the increase of osmotic pressure in the intestinal lumen after infection, and a large amount of fluid enters the intestinal lumen, resulting in nausea and vomiting.
Symptoms are more pronounced in young children than in adult patients.
Abdominal pain
Mainly related to the acceleration of gastrointestinal peristalsis, abdominal pain can be relieved after vomiting.
Fever
Fever is mainly caused by viral infection.
Fever can be seen in norovirus infections, while fever is uncommon in cases of embedded cupripovirus infections.
Diarrhea, watery stools
Patients with rotavirus gastroenteritis have prolonged diarrhea, up to about 2 weeks.
Symptoms of rotavirus gastroenteritis are characterized by diarrhea and watery stools.
Other symptoms
Some adenovirus infections are associated with sore throat and cough.
Some norovirus infections may be accompanied by muscle aches and pains.
Complications
Viral gastroenteritis may lead to the following complications.
Water and electrolyte balance disorders
It is one of the common complications of viral gastroenteritis.
It is caused by massive diarrhea and vomiting of the organism.
Patients are seen with poor skin elasticity, weakness, severe dry mouth and panic.
Acidosis
It is one of the common complications of viral gastroenteritis.
It is associated with frequent nausea and vomiting and large loss of gastrointestinal fluid in patients.
The patient is unresponsive, irritable, and fatigued.
Consultation
Department of Medicine
Gastroenterology
It is recommended to consult the Department of Gastroenterology when the patient experiences nausea, vomiting, abdominal pain, diarrhea and other symptoms.
Department of Infectious Diseases
When patients experience symptoms such as fever, diarrhea, and fatigue, it is recommended that they consult the Department of Infectious Diseases promptly.
Pediatrics
Children may consult the Department of Pediatrics when they experience the above symptoms.
Preparation for medical treatment
Preparing for the consultation: registration, preparation of documents, common problems
Tips for medical treatment
Before consultation, bed rest is recommended. Drink plenty of fluids.
Try to record the shape, color and frequency of stools, and if necessary, take photos for easy viewing during the visit.
Preparation Checklist
症状清单
Pay special attention to the time of onset of symptoms, special manifestations, etc.
Is there nausea, vomiting?
Is there diarrhea, abdominal pain? How many times does diarrhea occur and what is the nature of the stool?
Is there fever? What is the highest temperature?
病史清单
Was there any unclean eating or drinking before the onset of the illness?
检查清单
Test results in the past month, which can be brought to the doctor’s office.
Laboratory tests: routine blood test, routine stool test, etc.
Other tests: nucleic acid electrophoresis profiling, pathogenetic tests, etc.
用药清单
Medication in the last 2 weeks, if available, bring along the box or package for medical consultation
Antidiarrheal medication: Montelukast, etc.
Antispasmodic and analgesic medications: scopolamine, scopolamine, etc.
Diagnosis
Diagnosis is based on
medical history
There may be a history of unclean eating prior to the onset of the disease.
Clinical manifestations
症状
Patients often have nausea, vomiting, abdominal pain, diarrhea and other symptoms.
Some patients have fever and malaise.
体征
Some patients may have pressure pain in the abdomen, mostly around the umbilicus.
Laboratory examination
血常规检查
The total number of peripheral blood leukocytes is mostly normal, and a few may be slightly elevated, suggesting a possible viral infection.
便常规检查
It is of diagnostic significance in clarifying whether the patient has an infection or not.
The appearance of feces is mostly yellow and watery. Microscopic examination of the feces is free of pus cells and red blood cells, sometimes there may be a small number of white blood cells.
凝胶电泳分析
Polyacrylamide gel electrophoresis (PAGE) of viral RNA extracted from fecal extracts can be used to diagnose rotavirus infection by analyzing and judging according to the special distribution maps of 11 gene fragments of rotavirus in groups A, B and C.
The application of PCR technology to detect enteric adenovirus nucleic acids in fecal specimens allows sequencing, quantification and typing of enteric adenovirus.
血清抗体检查
The presence of rotavirus infection is indicated when rotavirus IgA antibodies are detected.
Differential diagnosis
Viral gastroenteritis should be differentiated from bacterial gastroenteritis, fungal gastroenteritis, parasitic gastroenteritis, and noninfectious gastroenteritis:
Bacterial gastroenteritis
Similarities: both are seen with similar symptoms such as abdominal pain and diarrhea.
Differences:
细菌性胃肠炎的发生因细菌感染机体所致，患者可见恶心、呕吐、排泄物伴有酸臭味。血常规检查可见中性粒细胞含量明显升高。
病毒性胃肠炎起病急骤，因病毒感染所致，患者可见发热，肉眼见粪便以黄色水样便为主。血常规外周血白细胞总数多为正常，少数可稍升高，凝胶电泳分析可以辅助鉴别。
Non-infectious gastroenteritis
Similarities: nausea, vomiting and other symptoms can be seen in both.
Differences:
非感染性胃肠炎并无传染性，症状以轻度腹泻为主，同时可伴食欲不振，血常规、凝胶电泳分析等检查无异常。
病毒性胃肠炎可有传染性，可经粪-口、呼吸、人与人之间接触等进行传播，血常规外周血白细胞总数多为正常，少数可稍升高，凝胶电泳分析可以辅助鉴别。
Treatment
Aim of treatment: to alleviate the patient’s symptoms, control the progression of the disease, and prevent and minimize complications.
Treatment principle: according to the severity of the disease, mainly for diarrhea and dehydration for symptomatic and supportive treatment, for severe patients to correct acidosis and electrolyte disorders and other comprehensive treatment.
General treatment
Rest
Bed rest, reduce strenuous exercise.
Rehydration
Drink plenty of warm water.
Mild dehydration and electrolyte disorders can be treated by oral administration of salted rice soup, sweetened saline or oral rehydration salts.
Severe dehydration should receive intravenous rehydration, with attention to potassium supplementation, and sodium bicarbonate to correct acidosis.
When the situation improves, it should be changed to oral rehydration.
Drug treatment
There is no specific treatment drug, mainly for diarrhea, abdominal pain, dehydration, symptomatic and supportive treatment, antibacterial drugs are ineffective.
Probiotics
Common probiotics include Bifidobacterium, Bacillus licheniformis, yeast and so on.
They are used to improve patients’ diarrhea symptoms by inhibiting the growth of harmful intestinal bacteria and maintaining the balance of flora in the gastrointestinal tract.
Drugs to relieve abdominal pain
Commonly used drugs include scopolamine, scopolamine and so on.
They can reduce gastrointestinal spasm and improve abdominal pain symptoms.
Long-term use of patients may have dry mouth, blurred vision, red face and other adverse manifestations.
Anti-diarrhea drugs
Commonly used drugs include montelukast and elimination of cardotoxin.
WHO recommends montelukast as an adjunctive treatment for diarrhea, which is effective for all kinds of diarrhea and neonatal diarrhea, especially in the treatment of rotavirus diarrhea with significant efficacy and small adverse reactions.
Prognosis
Cure
Viral gastroenteritis is a self-limiting disease, and patients can usually recover spontaneously in about 3~5 days.
Some patients may develop complications such as dehydration and acidosis.
The prognosis of viral gastroenteritis is related to the patient’s condition and whether or not the patient is actively treated.
Between 3% and 10% of infants and children with diarrhea need to be hospitalized because of severe dehydration.
Daily Management
Daily Management
Dietary management
Drink plenty of fluids to replace lost water.
Those with frequent vomiting and diarrhea should fast for 8 to 12 hours, and then gradually resume a normal diet.
During the recovery period, a light, low-fat diet should be adopted, avoiding too much spicy stimulation as well as fatty, sweet and greasy food, such as preserved sausage, salted meat and fried food, to avoid gastrointestinal discomfort.
Life management
Be in a happy mood, relax your mind and don’t give yourself too much mental pressure.
Avoid staying up late and pay attention to rest.
Disease monitoring
Patients should pay attention to the daily monitoring of the number of stools per day, the amount of defecation, the fecal character, the number of vomiting, the amount of urine, and the mental state.
At the same time, patients should pay attention to monitoring daily body temperature to determine whether there is fever.
Prevention
Prevention of viral gastroenteritis includes avoiding contact with infectious agents, cutting off transmission routes, and protecting susceptible people.
Avoid contact with infectious agents
In case of acute nausea, vomiting, abdominal pain, diarrhea, fever, etc., seek medical attention immediately, and family members should help to disinfect the vomit and excreta.
Cohabiting family members need to do a good job of personal disinfection and isolation with the help of medical professionals.
Cutting off the means of transmission
Enhance water and food hygiene to protect water sources from fecal contamination.
Reasonable diet, ensure dietary as well as drinking water hygiene should be strengthened personal hand hygiene, so as to avoid the disease entering through the mouth.
Pay attention to strengthen hand hygiene and maintain good personal hygiene habits.
Do not eat raw, cold and spoiled food.
Protection of susceptible groups
Protective isolation should be done for infants, young children, the elderly, and immunocompromised people who have suffered from chronic diseases such as diabetes, hypertension, leukemia, and malignant tumors.
It is recommended that aerobic exercise, such as jogging, walking, bicycling, etc., should be performed at least 3 times a week for 30 minutes each time to enhance physical fitness.
Oral attenuated rotavirus vaccine for infants and children aged 6 to 24 months is the most effective way to prevent rotavirus gastroenteritis.
Breastfeeding can reduce the symptoms and incidence of rotavirus diarrhea in infants and young children.
参考文献
[1]
李兰娟，任红. 传染病学[M]. 第9版. 北京: 人民卫生出版社，2018: 62-67.
[2]
李兰娟，王宇明. 感染病学[M]. 第3版. 北京： 人民卫生出版社，2015： 142-147.
[3]
王亚燕. 消化疾病诊疗学[M[. 科学技术文献出版社，2019：138.
[4]
金未来，唐国荣，李征瀛，等. 362例6岁以下儿童诺如病毒性胃肠炎诊治分析[J].重庆医学，2017，46(34): 4848-4850.
[5]
付建光，祁贤，吴斌，等. 病毒性胃肠炎的病原学检测[J]. 现代预防医学，2012，39(23): 6288-6289.
[6]
邓莉. 儿童病毒性胃肠炎. 实用儿科临床杂志，2011，26(10):727-730.
[7]
郑友限，陈志扬，郑丹凤,等. 2014—2017年泉州地区急性胃肠炎暴发疫情中诺如病毒的病原特征. 中华实验和临床病毒学杂志，2019，33(3):267-270.
[8]
Montgomery JR, Throckmorton K, Pickering LK. Viral gastroenteritis. Prim Care. 1988 Mar;15(1):43-62. PMID: 3043499.
[9]
Dennehy PH. Viral gastroenteritis in children. Pediatr Infect Dis J. 2011 Jan;30(1):63-4. doi: 10.1097/INF.0b013e3182059102. PMID: 21173676.
[10]
Ahmed SM, Hall AJ, Robinson AE,et al. Global prevalence of norovirus in cases of gastroenteritis: a systematic review and meta-analysis. Lancet Infect Dis. 2014 Aug;14(8):725-730.