Rhinoviruses

Rhinoviruses are a genus of small, non-enveloped, positive-sense RNA viruses in the family Picornaviridae. The genome is about 7.2 kilobases long and encodes a single polyprotein processed into structural proteins VP1–VP4 and various nonstructural proteins. The genus includes Human rhinovirus A, B, and C species, which together account for most human rhinovirus infections.

Rhinoviruses are the leading cause of the common cold worldwide. They are highly diverse, with more than 100 serotypes, contributing to frequent reinfections. They replicate best at around 33°C in the nasal mucosa and are transmitted primarily by respiratory droplets, direct contact, and contaminated surfaces.

Clinically, rhinovirus infection typically presents after a 1–3 day incubation with nasal congestion, rhinorrhea, sore throat, sneezing, cough, and malaise. Fever is uncommon in adults but can occur in children, and individuals with asthma or chronic obstructive pulmonary disease may experience exacerbations.

Pathogenesis involves infection of the upper airway epithelium with inflammatory responses leading to mucous production and congestion. Diagnosis is usually clinical, but RT-PCR can detect rhinovirus RNA from nasal swabs, especially in research or atypical cases.

There is no widely approved antiviral or vaccine for routine use against rhinoviruses. Treatment is supportive, focusing on hydration and symptom relief. Prevention emphasizes good hand hygiene, surface disinfection, avoiding close contact with infected individuals, and general measures to reduce respiratory spread. Complications can include secondary bacterial sinusitis or otitis media, particularly in children.