Rotavirus

Virus that causes gastroenteritis

Reconstruction of a rotavirus particle

Rotavirus is a genus of double-stranded RNA virus in the family Reoviridae. It is the most common cause of severe gastroenteritis in infants and young children worldwide. Nearly every child in the world is infected with rotavirus at least once by the age of five. Immunity develops with each infection, so subsequent infections are less severe; adults are rarely affected.

Virology

Structure of a rotavirus particle

Rotavirus is a non-enveloped virus with a triple-layered icosahedral protein capsid. The virus particle, or virion, is about 70 nm in diameter. The genome consists of 11 segments of double-stranded RNA, which encode six structural proteins (VP1-VP4, VP6, and VP7) and six non-structural proteins (NSP1-NSP6).

The outer layer of the virus is composed of VP7 and VP4, which are important for the virus's ability to infect cells and are the targets of neutralizing antibodies. The intermediate layer is made up of VP6, which is the most abundant protein and is used in diagnostic tests. The inner layer contains VP2, which surrounds the RNA segments and the RNA-dependent RNA polymerase, VP1.

Pathogenesis

Rotavirus particles labeled with gold-labeled monoclonal antibody

Rotavirus primarily infects the enterocytes of the small intestine, leading to diarrhea and vomiting. The virus disrupts the normal absorption of nutrients and water, causing the characteristic symptoms of rotavirus infection. The NSP4 protein acts as an enterotoxin, contributing to the diarrhea by altering the function of the enterocytes.

Epidemiology

File:Rotavirus Seasonal Distribution.png

Seasonal distribution of rotavirus infections

Rotavirus infections occur worldwide, with a seasonal pattern in temperate climates, peaking in the winter months. In tropical regions, rotavirus infections occur year-round. The virus is highly contagious and spreads through the fecal-oral route, often via contaminated hands, surfaces, and objects.

Clinical Features

The incubation period for rotavirus is approximately two days. The disease typically begins with fever and vomiting, followed by three to eight days of watery diarrhea. Severe dehydration is the most common complication, which can be life-threatening if not treated promptly.

Diagnosis

Diagnosis of rotavirus infection is primarily based on the detection of the virus in stool samples. Enzyme immunoassays (EIAs) are commonly used to detect rotavirus antigens. Molecular methods, such as reverse transcription-polymerase chain reaction (RT-PCR), can also be used to detect and characterize the virus.

Prevention

Avertable deaths from rotavirus with full vaccine coverage

Vaccination is the most effective method of preventing rotavirus infection. Two vaccines, Rotarix and RotaTeq, are widely used and have significantly reduced the incidence of rotavirus gastroenteritis. These vaccines are administered orally and are included in the immunization schedules of many countries.

Treatment

Rotavirus infection in the gut

There is no specific antiviral treatment for rotavirus infection. Management focuses on maintaining hydration through oral rehydration solutions or intravenous fluids in severe cases. Zinc supplementation and continued feeding are also recommended to support recovery.

Research

Research on rotavirus continues to focus on improving vaccine efficacy, understanding the virus's molecular biology, and developing new therapeutic strategies. Studies are also exploring the impact of rotavirus vaccination on the incidence of other gastrointestinal infections.

Related pages

• Gastroenteritis
• Viral infection
• Vaccination