Order: Picornavirales

Family: Picornaviridae

Genus: Enterovirus


Rhinovirus A

Rhinovirus B

Rhinovirus C

The most common viral infectious agents in humans and are the predominant cause of the common cold.

Proliferates in temperatures between 33–35 °C (91–95 °F), the temperatures found in the nose.

The 99 recognized types of human rhinoviruses differ according to their surface proteins.

Rhinoviruses are lytic in nature.

Is among the smallest of viruses, with diameters of about 30 nanometers.

Other viruses are around 10 times larger at about 300 nanometers.

Transmission: via aerosols of respiratory droplets and from contaminated surfaces, including direct person-to-person contact.

Occurs worldwide.

The primary cause of common colds.

Rhinovirus symptoms include: sore throat, runny nose, nasal congestion, sneezing and cough.

Rhinovirus infections sometimes are accompanied by muscle aches, fatigue, malaise, headache, muscle weakness, or loss of appetite.

Children may have six to twelve colds a year.

The incidence of colds is higher in the autumn and winter, with most infections occurring between September to April.

The seasonality of colds may be due to the start of the school year, and people spending more time indoors increasing the chance of transmission of the virus.

Rhinoviruses preferentially replicate at 32°C (89°F) as opposed to 37°C (98°F), and temperatures may also be factor in seasonal variation of colds, as the upper respiratory tract where respiratory airflow is in continual contact with the colder environment.

The upper respiratory tract of the mouth and nose is primary route of entry for human rhinoviruses.

Following entry, the virus binds to ICAM-1 (Inter-Cellular Adhesion Molecule 1. receptors on respiratory epithelial cells

The ICAM-1 (Inter-Cellular Adhesion Molecule 1) is also known as CD54 (Cluster of Differentiation 54).

Infected cells release chemokines and cytokines, which in turn activate inflammatory mediators.

The virus replicates and spreads to other cells rapidly.

The virus adheres to epithelial surface cell receptors within 15 minutes of entering the respiratory tract. spreading rapidly.

At the upper respiratory epithelium level cell lysis occurs.

Almost 50% of infected patients will manifest symptoms by 2 days.

About 5% of individuals will have an incubation period of less than 20 hours, and 5% of cases have an incubation period of greater than four and a half days.

Individuals at highest risk are children and the elderly.

Rhinoviruses associated with the majority of asthma exacerbations, as rhinovirus infection of airway epithelium induces ICAM-1.

With asthma intercellular adhesion molecule 1 (ICAM-1) has a central role in airway inflammation in asthma, and it is the receptor for 90% of Human rhinoviruses.

There are no vaccines against these viruses, and there is little-to-no cross-protection between serotypes.

At least 99 serotypes of Human rhinoviruses affecting humans have been sequenced.

It is extremely contagious during the cold months of each year.

Rhinovirus can live up to 3 hours outside human contact.

Once contracted, a person is most contagious within the first 3 days.

Avoid touching the mouth or nose, as those are the most common portals of entry for the virus.

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