Rhinovirus

Rhinovirus is a genus of small, non-enveloped, positive-sense RNA viruses in the family Picornaviridae. It includes species A, B, and C and is the most common cause of the common cold. More than 100 serotypes exist, contributing to frequent reinfections.

The virion is non-enveloped, icosahedral, about 30 nm. The genome is a single-stranded, positive-sense RNA of approximately 7.2 kilobases that encodes a single polyprotein processed into structural proteins VP1-4 and nonstructural proteins.

Most rhinoviruses attach to ICAM-1, while some use other receptors; rhinovirus C uses CDHR3. They replicate best at cooler temperatures around 33°C in the nasal mucosa.

Spread by respiratory droplets and contact with contaminated surfaces; incubation 1-3 days; symptoms include nasal congestion, rhinorrhea, sore throat, and cough. Fever is more common in children. Complications such as otitis media and sinusitis can occur, especially with prolonged infection.

Diagnosis is usually clinical; molecular tests (RT-PCR) can confirm in some settings. There is no approved vaccine or specific antiviral therapy; management is supportive, including fluids, analgesics, and decongestants. Preventive measures include hand hygiene and avoiding touching the face.

Rhinoviruses are a leading cause of acute respiratory infections worldwide. They circulate year-round with seasonal peaks in fall and spring in temperate climates. High serotype diversity allows frequent reinfections; immunity is partial and type-specific.