Viral Gastroenteritis

Viral gastroenteritis, also called viral diarrhea, is a group of acute intestinal infectious diseases caused by various viruses. Among global infectious diseases, infectious diarrhea ranks third in incidence. Statistics show infectious diarrhea accounts for 60%-90% of diarrhea cases of various causes, mostly acute; pathogens include bacteria, protozoa, viruses, and fungi, but acute viral gastroenteritis is most common. Clinical features are abrupt onset, nausea, vomiting, abdominal pain, diarrhea with watery or loose stool, and sometimes fever and general malaise, with a short course and low fatality. Gastroenteritis caused by various viruses is clinically similar. Among the many viruses associated with acute gastroenteritis, the most important and studied are rotavirus and Norwalk-like viruses. In addition, calicivirus, enteric adenovirus, astrovirus, coxsackievirus, and coronavirus can also cause gastroenteritis. Rotaviral gastroenteritis is the most common type of viral gastroenteritis; ordinary rotavirus mainly affects infants, while adult diarrhea rotavirus can cause outbreaks in young adults.

Common Symptoms

Fever with abdominal pain; ...; dehydration; mucoid stool; watery diarrhea with mucus...

Causes and Pathogenesis

Pathogenesis and pathology: 1. Rotavirus mainly invades small intestinal villous epithelial cells, causing sloughing replaced by squamous or cuboidal cells lacking digestive enzymes. Brush-border enzymes such as maltase, sucrase, and lactase decrease, causing absorption dysfunction. Undigested lactose and other disaccharides accumulate, altering osmotic pressure and causing osmotic diarrhea. Lesions are mainly in the duodenum and jejunum; most mucosal cells remain normal, with vacuolar degeneration in villus cells and numerous rotavirus particles in the ER. 2. Norovirus is a group of morphologically similar, slightly antigenically distinct virus particles. The prototype was the pathogen of a 1968 acute gastroenteritis outbreak in Norwalk, USA; subsequently, similar particles were found worldwide, named after their isolation sites (Hawaii virus, Snow Mountain virus, Mexico virus, Southampton virus), collectively called Norwalk-like viruses. Worldwide, 60%-80% of human gastroenteritis outbreaks are associated with norovirus. Infection occurs year-round without clear geographic difference; main transmission is fecal-oral, person-to-person contact, and airborne. Outbreaks mainly occur in restaurants, schools, hospitals, nurseries, tourist areas, and military units. The population is generally susceptible; antibodies do not provide solid protection, so reinfection is common, though symptoms are milder than rotavirus. 3. Astrovirus was first detected by electron microscopy in 1975 in the stool of infants with mild diarrhea. Serologic surveys show infection rate >70% by age 5. It can cause outbreaks in hospitals, daycare centers, schools, and military units. It occurs sporadically or in outbreaks, distributed worldwide; serotype 1 predominates. Similar to rotavirus, it mainly affects children under 2, especially under 1; the elderly and immunocompromised are also at high risk. It has been reported in HIV-infected patients, bone marrow transplant recipients, and combined immunodeficiency patients, and is also a cause of acute gastroenteritis in healthy adults. 4. Adenovirus contains double-stranded DNA, averaging 70 nm in diameter; 52 serotypes are known, plus some untypeable strains. Ordinary adenoviruses grow on standard cell cultures, but enteric adenoviruses grow selectively in small intestinal cells. Adenoviral gastroenteritis is worldwide, second only to rotaviral enteritis in children; onset is mainly under 5 years, especially under 3 (85%), minimum age 1 month. It is usually sporadic but can cause outbreaks in refugee camps, nurseries, and pediatric wards, occurring year-round with slight peaks in summer and late winter. 70% are caused by Ad40 and Ad41; other types such as 1, 2, and 4 are also reported, varying by country and region.

Treatment

Drug therapy, supportive therapy

Preventive Measures

Early detection and isolation of patients; disinfect patient feces; emphasize water source and food hygiene; disinfect utensils; nurseries should have strict disinfection and isolation protocols.

Department to Visit

It is recommended to visit the Gastroenterology department; an appointment can be booked on this platform before the visit.

Warm reminder: The above information is for health science reference only and cannot replace professional medical diagnosis. If you have related symptoms, please seek medical attention at a regular hospital promptly.