Rhinovirus infection (common cold)
General or Other | General Practice | Rhinovirus infection (common cold) (Disease)
Rhinoviruses belong to the Picornaviridae family, which includes the genera Enterovirus (polioviruses, coxsackieviruses groups A and B, echoviruses, numbered enteroviruses, parechoviruses) and Hepatovirus (hepatitis A virus). The symptoms of a rhinovirus infection are well known: discharging or blocked nasal passages often accompanied by sneezes, and perhaps a sore throat. This typical runny nose (rhinorhea) may be accompanied by a general malaise, cough, sore throat etc.
The characteristic symptoms occur from one to four days after infection at which time extremely high titers of the rhinovirus are found in the nasal secretions (there can be as many as 1000 infectious virus particles per ml). It appears that one rhinovirus infectious virion particle is capable of initiating disease.
Causes and Risk factors
It is estimated that about one third of colds are caused by rhinovirus infections. There are more than 100 serotypes explaining why vaccines against rhinoviruses have proved difficult to develop. Rhinoviruses (RVs) cause or predispose to various upper respiratory infections (URIs) and lower respiratory infections (LRI), which are less common.
The virus replicates itself primarily in epithelial cells of the nasal mucosa but there is little damage to the mucosa although infected cells may be sloughed off. There may be edema of connective tissue.
Diagnosis and Treatment
There is usually no need to treat the infection although treatment of the symptoms may be used. This often consists of rehydration and keeping the airways unblocked. Physicians often prescribe aspirin to relive fever symptoms but this may exacerbate viral proliferation if body temperature is reduced since, as noted above, the virus is particularly temperature-sensitive.