Log in
Microbiology · Reoviruses (Rotaviruses)

Rotaviruses

Rotavirus

Rotaviruses are RNA-containing viruses of the family Reoviridae, which are the main causative agents of acute gastroenteritis in children. They got their name from their characteristic morphological structure resembling a cogwheel.

Test your knowledge on this topicAsk the AI
GenomeDouble-stranded RNA (11 segments)
CapsidTriple-layered, non-enveloped
Size80 nm in diameter
Incubation1 to 3 days
TransmissionFecal-oral route
3 min readFor medical studentsUpdated Sep 25, 2026
Material prepared by WhiteCoat Pro editorial team based on platform study guidesReviewed by medical editor: Aulov A. A., general practitioner · 09/24/2026

Morphology and genome structure

Rotaviruses are spherical in shape with a diameter of 80 nm. The genome is represented by fragmented double-stranded RNA (dsRNA), which consists of 11 segments. Each RNA molecule includes both plus- and minus-strands.

Virions lack an outer envelope, but possess a unique triple-layered capsid consisting of 12 proteins. Visually, it resembles a wheel:

  • Inner capsid is formed by the VP-2 protein.
  • Intermediate capsid ("spokes") consists of the VP-6 protein.
  • Outer capsid is formed by the type-specific VP-7 antigen and spikes made of the VP-4 protein (hemagglutinin and attachment protein).

Viral life cycle

Rotavirus replication is a complex process that begins with the cleavage of the VP-4 protein by gastrointestinal tract enzymes into VP-5 and VP-8 subunits. This is necessary for virion activation.

  1. Penetration: The VP-8 subunit binds to sialic acids of the target cell, after which the virus enters via endocytosis.
  2. Transcription: Inside the endosome, the virion loses its outer layer, turning into a double-layered particle. In the cytosol, the polymerase complex (VP-1 and VP-3) is activated, synthesizing (+)RNA.
  3. Protein synthesis and assembly: Non-structural proteins (NSP-2 – NSP-5) form viroplasms — the sites for assembly of new particles and genome replication.
  4. Maturation: Double-layered particles move to the endoplasmic reticulum (ER), where the outer capsid is assembled with the help of the NSP-4 protein.
  5. Release: New virions leave the cell either by lysis or via exocytosis.
Test your knowledge on this topicAssignments from the Microbiology course bank — instant answers and explanations.

Pathogenesis and epidemiology

Non-structural viral proteins play an important role in the development of the disease. Of particular significance is NSP-4, the first described viral enterotoxin. It is responsible for the development of secretory diarrhea.

Rotaviruses are divided into 7 serogroups (A–G). Serogroups A, B, and C cause disease in both humans and animals, whereas the rest are pathogenic only to animals. The causative agent exhibits high persistence in the environment. Transmission occurs via the fecal-oral mechanism (primarily waterborne, as well as through food and household items).

Briefly: answers to topical questions

What clinical symptoms are characteristic of rotavirus infection in children?

Rotavirus infection in children is characterized by an acute onset with gastroenteritis, fever, and catarrhal syndrome. Full manifestation of symptoms develops within the first 24 hours.

Main clinical manifestations:

  • Gastroenteritis — includes vomiting, abdominal pain, and frequent watery diarrhea (secretory diarrhea with a frequency of 10–15 times per day).
  • Fever — body temperature rises to 38.5 °C and above.
  • Catarrhal syndrome — often precedes diarrhea, causing combined lesions of the respiratory system and gastrointestinal tract in 60–70% of patients.

The duration of acute manifestations of the disease is usually 1–2 days.

How to memorize

To remember the capsid structure, use the "wheel" rule: Inside is the axle (VP-2), from it extend the spokes (VP-6), and on the outside is the tire (VP-7) with spikes for road grip (VP-4).

Class and exam questions

Which protein is responsible for virus adsorption?

The outer capsid protein VP-4 (specifically its VP-8 subunit) is responsible for attachment to the cell.

Where does the assembly of new viral particles take place?

Intracellular assembly and genome replication take place in special cytoplasmic inclusions called viroplasms.

Why does the virus cause diarrhea?

Rotavirus synthesizes the non-structural protein NSP-4, which acts as a viral enterotoxin and stimulates secretory diarrhea.

Something unclear? Ask the AIThe AI tutor has read the material on "Rotaviruses" and will explain it in simple terms.

What else to study on this topic

  • The role of sialic acids in adsorption
  • Mechanism of virion activation by GI tract proteases
  • Functions of plus-strand RNA in translation
  • Interaction of the virion with ER membranes

Study the full topic in the «Microbiology» course

This is a summary. The course covers everything tested in classes and exams.

  • Complete study guide on "Rotaviruses" and 4,383 other subject pages
  • Assignments and quizzes after every topic — just like in a colloquium
  • AI tutor answers questions on the topic anytime
  • 141 video lectures on the subject
Open full reviewSubject curriculumfrom 599 ₽ per month

Other topics in the "Reoviruses (Rotaviruses)" section

Foot-and-mouth disease virusReoviruses
The entire "Reoviruses (Rotaviruses)" section

Free video lessons: microbiologyShort lessons with study notes — no registration required.

Watch lessons

Prepared by WhiteCoat Pro faculty in accordance with the medical school curriculum. For educational purposes only.