Introduction to rotavirus

Rotavirus is one of the major pathogens causing diarrhea in infants. It mainly infects small intestinal epithelial cells, resulting in cell damage and diarrhea. Rotavirus in the summer and autumn and winter each year, the infection pathways for the fecal - oral route, the clinical manifestations of acute gastroenteritis, was osmotic diarrhea, duration of 7 days, fever for 3 days, vomiting 2 to 3 days, diarrhea 5 Day, severe dehydration symptoms.

Rotavirus (Rotavirus, referred to as RV) is a double-stranded ribonucleic acid virus, belonging to the reovirus family. It is a single cause of infant and infant diarrhea, and almost every child in the world, about five years of age, has been infected with rotavirus at least once. However, after each infection will gradually increase the body's immune system, the impact of subsequent infection will be reduced, so adults are rarely affected. A total of seven species of rotavirus, numbered in English letters A, B, C, D, E, F and G. Among them, A species is the most common one, and human rotavirus infection in more than 90% of the cases are also caused by the species.

Rotavirus is transmitted through the fecal-oral route. It infects intestinal cells (enterocytes) that are linked to the small intestine and produce enterotoxins, which cause gastroenteritis, leading to severe diarrhea, and sometimes even death from dehydration. Although the rotavirus was discovered by Ruth Bishop of Australia in 1973 and caused more than 50% of infants and toddlers to be hospitalized for severe diarrhea, in the public health community It is still not widely appreciated, especially in developing countries. In addition to the impact on human health, rotavirus can also infect animals, is one of the pathogens of livestock.

The discovery history of rotavirus

In 1943, Jacob Light and Horace Hodes demonstrated that there is a viral vector in children infected with infectious diarrhea, which can also cause diarrhea in livestock . Thirty years later, the virus was preserved as a sample of rotavirus. During the intervening years, the virus in mice showed a correlation with viruses that caused diarrhea. In 1973, Ruth Bishop of Australia described a similar virus in a study on gastroenteritis in children.

In 1974, Thomas Henry Flewett (Thomas Henry Flewett) in the electron microscope after the virus was observed, it is recommended to be named "rotavirus" (rotavirus), because rotavirus particles look "Rota" in Latin means "round"; this name was officially approved four years later by the International Committee on Taxonomy of Viruses. In 1976, similar viruses were also described in many other species of animals. The viruses described in these reports all contribute to acute gastroenteritis and are identified as collective pathogens affecting humans and animals around the world. Rotavirus serotypes were first published in 1980, and in the following year, rotaviruses from the human body are produced by the addition of trypsin, an enzyme found in the mammalian duodenum, now known as rotavirus replication ) Was successfully cultivated for the first time in a cell culture obtained from a monkey kidney in a natural environment. The ability to successfully cultivate rotaviruses has accelerated the pace of research, and in the mid-1980s, the first candidate vaccines had begun to be evaluated.

In 1998, the first rotavirus vaccine was licensed in the United States. In the United States, Finland and Venezuela clinical trials found that the vaccine can be successful for the prevention of rotavirus A kinds of severe diarrhea rate as high as 80% to 100%, and the researchers did not find significant adverse drug reactions. However, after the vaccine was found to increase the risk of intussusception (ie, a type of bowel obstruction), vaccine manufacturers withdrew all of the vaccine from the market in 1999, and studies have shown that every 12,000 doses of vaccine Infants have a symptom of intussusception. The experience also sparked a heated debate about the risks and benefits associated with rotavirus vaccines. In 2006, two new vaccines against rotavirus A proved to be safe and effective for children.

Route of transmission

Rotaviruses are transmitted by the fecal-oral route and can be transmitted by contact with soiled hands, soiled surfaces, and soiled objects, and may be transmitted through respiratory pathways [1]. Fecal matter per gram of infected patients can contain more than 1000 trillion [data in question, the total weight of 10E19 viruses greater than 1 g] of infectious virus particles; and as long as 10 to 100 can be spread by While infecting another person.

Rotaviruses are stable in the natural environment and can be found in samples from estuaries where about one to five contagious rotavirus particles can be found per US gallon. Sanitary equipment to eliminate bacteria and parasites appears to be ineffective for rotavirus control because the incidence of rotavirus infection is similar in countries with high levels of hygiene and low levels of hygiene.

Pathogenesis

Diarrhea is caused by rotavirus multiple activities. Because intestinal cells called enterocytes are destroyed by the virus, resulting in malabsorption. The enterotoxin-producing viral protein, NSP4, produces a calcium-dependent chloride secretion that disrupts the water-reabsorption of the sodium-glucose transport 1 (SGLT1) vector, Reducing the activity of disaccharidase of the brush border film and possibly aggravating the reflection of calcium-dependent secretion in the enteric nervous system. Healthy intestinal mucosal cells secrete lactase into the small intestine; lactose intolerance caused by lactase deficiency is also a common symptom of rotavirus infection, which can last for several weeks. Recurrence of lactose intolerance is often associated with the reintroduction of milk into the daily diet of children, as the bacteria ferment the disaccharides lactose in the stomach.

Diagnostic testing

The diagnosis of rotavirus infection is normal after diagnosis of gastroenteritis and severe diarrhea. Most of the pediatric patients admitted to the hospital because of gastroenteritis were detected rotavirus A species. For rotavirus A specific infectious disease diagnosis is the way the patient's feces enzyme immunoassay to identify the virus. There are several approved monitoring devices on the market that are sensitive and individually detectable for all serotypes of rotavirus A strains. Other testing methods, such as electron microscopy or gel electrophoresis, are used in research laboratories. Reverse transcriptase polymerase chain reaction (RT-PCR) can detect and identify all species of human rotavirus with all serotypes.

Prevention measure

In 2006, two vaccines against rotavirus type A infection have been proven safe and effective for children: Rotarix® manufactured by GlaxoSmithKline, and by Merck Pharmaceuticals Quot; RotaTeq & quot;). & Lt; / RTI & gt; Both vaccines were given inoculatively and both included live force-free live viruses. Rotavirus vaccines are currently available in Australia, Europe, Canada, Brazil, Egypt, India, Israel, Taiwan, South Africa, Panama, Argentina and the United States.

The Rotavirus Vaccine Program is a Program for Appropriate Technology in Health (PATH), a collaboration between the World Health Organization (WHO) and the Centers for Disease Control and Prevention (CDC), which is funded by the Global Initiative on Vaccines and Immunization Alliance (GAVI Alliance) funding. The aim of the program is to reduce the incidence of childhood-related morbidity and mortality from diarrheal diseases by creating rotavirus vaccines that can be used in developing countries.