viral enteritis



OVERVIEW

Definition

Viral enteritis is a group of acute intestinal infectious diseases caused by a variety of viruses, with diarrhea and watery stools as the main clinical features, and is mostly self-limiting in those with normal immunity.

It can occur in all age groups and is more common in infants and young children; rotavirus, norovirus and enteric adenovirus are the most common pathogens.

Clinical symptoms include fever, nausea, anorexia, and abdominal pain.

Classification

According to the type of virus, it can be categorized into the following major types:

Rotavirus enteritis

Rotavirus is a spherical, double-stranded RNA virus that resembles a wheel, hence its name. Rotaviruses are stable in the external environment, resistant to acid, alkali and ether, and can survive for up to 7 months at room temperature.

Rotavirus mainly invades the duodenum and jejunum, replicates in the epithelial cells, causing damage to the epithelial cells of the intestinal villi, causing lactose to accumulate in the intestinal lumen resulting in high osmolality in the intestinal lumen, and water enters into the intestinal lumen, leading to diarrhea and vomiting.

Norovirus enteritis

Norovirus is an envelope-less, single-stranded RNA virus that is highly resistant to various physical and chemical factors and is highly infectious.

The virus mainly replicates in the cytoplasm of the intestinal mucosa, which can cause reversible lesions in the mucosa of the duodenum and jejunum, making the villi of the intestinal mucosal epithelial cells shorter and duller, resulting in the impaired absorption of fats and disaccharides, the osmotic pressure in the intestinal lumen increases, and the liquid enters into the intestinal tract, which results in nausea and vomiting and diarrhea, and other symptoms.

Enteric adenovirus enteritis

Enteric adenovirus is a non-enveloped, spherical, double-stranded linear DNA virus that is acid and alkali resistant, sensitive to formaldehyde and ultraviolet light, and highly resistant to bile salts, and can survive in the intestine.

Enteric adenovirus mainly infects the jejunum and ileum. Viral infection can shorten and reduce the intestinal mucosal villi, prompting cell degeneration and lysis, and causing diarrhea due to impaired absorption in the small intestine.

Pathogenesis

Viral enteritis infectious source of human and animal, the transmission pathway to fecal-oral transmission and human-human contact infection, the population is generally susceptible.

Due to the different pathogens, there are some differences in epidemiology.

Rotavirus enteritis

It is more common in fall and winter, and is more common in children than adults.

Group A rotavirus infections are distributed worldwide and mainly infect infants and young children, with the highest incidence at 6-24 months of age.

Group B rotavirus is generally susceptible to adults, mainly infecting young adults, with the highest incidence in people aged 20-40 years old, mainly occurring in China, mainly in outbreak epidemics, mostly occurring in April-July.

Group C rotavirus mainly infects children, with occasional occurrence in adults, mostly disseminated, with occasional small-scale epidemics[1] .

Norovirus enteritis

Noroviral enteritis is a widespread disease that affects adults and older children.

Norovirus is a global epidemic, can occur throughout the year, more prevalent in autumn and winter, often outbreaks of epidemics, norovirus-induced diarrhea accounted for more than 1/3 of acute non-bacterial diarrhea.

Enteric adenovirus enteritis

Enteric adenovirus is generally susceptible to the population, the vast majority of children under 3 years of age, 6-12 months of age is more common in young children, adults have fewer cases.

The disease can occur throughout the year, with a higher incidence in summer and fall. Most of them are disseminated or endemic. It is the second most common form of diarrhea among young children in China, second only to rotavirus.

Causes

Causes

Rotavirus: patients and asymptomatic carriers are the main source of infection [2], mainly through the fecal-oral route, but also through water contamination or respiratory transmission. Rotavirus is an important pathogen causing hospital-acquired infections.

Norovirus: the source of infection is mainly patients, latent infections and virus carriers, the main mode of transmission is fecal-oral route, can be distributed, but also through contaminated water, food, causing outbreaks, person-to-person contact and virus-containing aerosols can also be transmitted.

Enteric adenovirus: patients and invisible infected people are the only source of infection [3], digestive tract transmission and person-to-person contact is the main way, can also be infected through the respiratory tract.

Predisposing factors

Unclean diet

Eating raw, cold and undercooked food may cause the virus to be incompletely killed, thus allowing the virus to invade the human body, triggering the occurrence of viral enteritis or aggravating its symptoms.

Unhygienic eating habits

Failure to pay attention to hand hygiene before meals and after defecation, or failure to wash clean, can induce the occurrence of this disease.

Low immunity

Infants and young children whose immune systems are not yet fully developed, some elderly people with low immunity, and people suffering from other underlying diseases are susceptible to this disease because their immunity against external viruses is reduced.

Symptoms

Main Symptoms

Diarrhea

Diarrhea is the most important clinical manifestation, mostly dilute watery stools or eggdrop soup-like stools, with large amount and urgency, usually without pus and blood, only a few have mucus, stools may be yellow or yellowish-green, and some of them may be accompanied by abdominal distension and abdominal pain.

Rotavirus enteritis diarrhea occurs after nausea and vomiting, and the stools are mostly watery or yellowish-green loose stools without mucus and pus and blood, ranging from ten times a day to dozens of times a day. The duration of the disease is mostly 3-6 days, and occasionally can be as long as 10 days or more.

Norovirus enteritis diarrhea is often accompanied by abdominal pain, colic, stools are mostly yellow dilute watery stools or watery stools, no mucus, pus and blood, several times a day to dozens of times, the course of the disease generally 1-3 days can be self-cured.

Enteric adenovirus enteritis diarrhea is mostly dilute watery stools, dozens of times a day, accompanied by low fever and vomiting. The average duration of the disease is 8-12 days.

Nausea and vomiting

Some patients have nausea and vomiting with stomach contents. Symptoms are more pronounced in young children than in adult patients.

Fever

Depending on the extent of the disease, there may be different degrees of fever, which usually improves after the infection is under control.

Respiratory symptoms

Some patients may have upper respiratory symptoms such as cough and runny nose, and severe cases may have bronchitis or pneumonia.

Complications

Severe dehydration and electrolyte disorders can occur in patients with severe disease, and patients can see poor skin elasticity, fatigue, severe dry mouth, panic and other manifestations, which is also the most common complication, and severe dehydration can even die due to water electrolyte disorders.

Other complications include acidosis, central nervous system symptoms (convulsions), cardiac damage (muffled heart sounds, arrhythmia, etc.) and hepatobiliary damage. Patients are unresponsive, irritable, fatigued, and convulsive.

Consultation

Department of Medicine

Department of Infectious Diseases

If you have diarrhea, loose watery stools or eggdrop soup-like stools, accompanied by nausea, vomiting, abdominal pain, abdominal distension, accompanied by fever and cough and other respiratory symptoms, it is recommended that you consult the Department of Infectious Diseases in a timely manner.

Gastroenterology

When you are not sure if the diarrhea is viral but accompanied by symptoms such as abdominal pain, fever, nausea, and vomiting, you may consult the Department of Gastroenterology.

Pediatrics

Pediatric patients may also consult the Department of Pediatrics or the Division of Pediatric Internal Medicine when the symptoms described above are present.

Preparation

Preparing for your visit: registering, preparing your documents, and frequently asked questions.

Tips for medical treatment

Before consultation, bed rest is recommended. Drink plenty of fluids.

If you have a bowel movement, remember the nature, color and frequency of the bowel movement, and take a picture of it.

Preparation Checklist

Pay particular attention to the time of onset of symptoms, special manifestations, etc.

Has the diarrhea been preceded by eating unclean food or getting cold?

How long has the diarrhea lasted and how many times a day?

Is there mucus, pus or blood in the stool?

Is it accompanied by nausea, vomiting, fever, cough?

Is there any discomfort such as abdominal pain or bloating?

Is there any past history of enteritis or diarrhea?

Test results in the last 1 month, which can be brought to the doctor’s office

Laboratory tests: blood test, stool test, electrolytes, etc.

Imaging tests: abdominal CT, etc.

Medication in the last 2 weeks, bring along the box or package if available

Antidiarrheal medications: montelukast, loperamide, etc.

Antispasmodics and analgesics: pivacurium bromide, scopolamine, etc.

Microecological preparations: Saccharomyces boulardii, Bifidobacterium triplex, etc.

Diagnosis

Diagnosis is based on

medical history

The patient may have a history of unclean eating prior to the onset of the disease.

Clinical manifestations

Diarrhea is the most typical manifestation, which may be accompanied by nausea and vomiting, abdominal distension and abdominal pain.

A small number of patients may have fever, cough, or even generalized multisystem manifestations.

Abdominal pain may be accompanied by abdominal tenderness, and most patients have hyperactive bowel sounds.

Laboratory tests

Most patients have a normal peripheral blood leukocyte count, while a small number of patients may have slightly higher leukocytes and lymphocytes, suggesting the possibility of viral infection.

It is of diagnostic significance in clarifying whether the patient is infected or not.

The appearance of feces is mostly yellow and watery. There are no pus cells and red blood cells in the feces under the microscope, and sometimes there may be a small number of white blood cells.

Electrolyte examination in some patients may show low potassium, low chloride and low sodium, which is related to acute dehydration.

Cultures are free of pathogenic bacterial growth.

Detection of rotavirus IgA antibodies suggests the presence of rotavirus infection.

Application of PCR technology to detect enteric adenovirus nucleic acids in fecal specimens allows sequencing, quantification and typing of enteric adenovirus [4].

Imaging

can be used to exclude diarrhea caused by other inflammatory or space-occupying lesions.

Differential diagnosis

Bacterial enteritis

Similarities: Both can cause diarrhea, nausea, vomiting, and fever.

Differences: Bacterial diarrhea is mostly caused by bacterial infections, with E. coli being the most common, and the routine blood results may have elevated neutrophils and be sensitive to antibiotic treatment. Viral enteritis blood routine is normal or there is a mild elevation of white blood cells and lymphocytes, and is ineffective for antibiotic treatment.

Ulcerative colitis

Similarities: Both can present with diarrhea.

Differences: ulcerative colitis is a chronic autoimmune disease, generally longer course of disease is easy to repeat, stools can be accompanied by obvious mucus and pus and blood, enteroscopy can be seen obvious congestion, edema, pseudo-polyps and other manifestations; and viral enteritis is generally shorter course of the disease, most of them do not have the manifestation of pus and blood, and other manifestations.

Treatment

The purpose of treatment: to alleviate the patient’s symptoms, control the development of the disease, prevent and reduce complications.

Treatment principle: there is no specific drug treatment, mainly for diarrhea and dehydration of the symptomatic and supportive treatment, antibacterial drugs are ineffective. Serious patients need to correct acidosis and electrolyte disorders.

General treatment

Bed rest, reduce strenuous exercise.

Drink plenty of warm water.

Mild dehydration and electrolyte disorders can be treated with oral salt-added rice soup, sugar-saline or oral rehydration solution.

Severe dehydration should receive intravenous rehydration, pay attention to potassium supplementation, and sodium bicarbonate should be used to correct acidosis.

Drug treatment

At present, there is no specific treatment drug, mainly for diarrhea, abdominal pain, dehydration, symptomatic and supportive treatment.

Antidiarrheal agents

Commonly used drugs include montelukast, elimination of Cardotril and so on.

Montelukast has strong immobilizing and inhibiting effects on viruses and their toxins in the digestive tract, making them lose their pathogenic effects; in addition, it also has strong covering and protecting abilities on the mucous membrane of the digestive tract, repairing and improving the mucous membrane barrier, etc., so it can be used as the first choice.

Elimination of polypeptide is an enkephalinase inhibitor, which can further prolong the physiological activity of endogenous enkephalin in the digestive tract and play the role of antidiarrheal.

Microecological agents

Commonly used drugs include Saccharomyces boulardii bulk, Bifidobacterium bifidum triplex, Bacillus licheniformis and so on.

Adapted to those with intestinal flora disorders, they can regulate the composition of intestinal flora and maintain or restore intestinal homeostasis [10].

Pay attention to allergic reactions, fungal infections and other adverse reactions.

Drugs to relieve abdominal pain

Commonly used drugs include scopolamine, scopolamine and so on.

They can reduce gastrointestinal spasm and improve abdominal pain symptoms.

Patients with long-term use may have adverse manifestations such as dry mouth, blurred vision, and red face.

Prognosis

Cure

Viral gastroenteritis is a self-limiting disease, and patients can usually recover spontaneously in about 3 to 5 days.

The prognosis of viral gastroenteritis is related to the patient’s condition and whether or not active treatment is given.

A small number of patients with diarrhea in infants and young children require hospitalization due to severe dehydration.

Daily

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 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., consult a doctor 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.

Cutting off the means of transmission

Eat a reasonable diet and ensure hygienic eating and drinking water.

Ensure good hand hygiene and maintain good personal hygiene.

Do not eat raw, cold or spoiled food.

Protecting susceptible groups

Protective isolation should be done for infants, young children, the elderly, people with previous underlying diseases and those with low immunity.

Exercise, such as jogging, walking, bicycling, etc., is recommended to enhance physical fitness.

Oral attenuated rotavirus vaccine for infants and young children between 6 and 24 months of age is currently the most effective way to prevent rotavirus gastroenteritis.

Breastfeeding can reduce the symptoms and incidence of rotavirus diarrhea in infants and young children.