Zoom in on microorganisms

Germs that infect humans



© Robert Alain, SME, INRS-Institut Armand-Frappier

Microorganism: rhinoviruses of the family Picornaviridae, which account for more than 30% of colds.

Disease: colds

Occurrence of the disease

Current situation: colds are common infections in humans of all ages.

Mechanism of action of the microorganism: the virus infects the nasal mucosa (the skin cells lining the inside of the nose).

Symptoms of the disease: partial obstruction of the nose, nasal discharge, throat irritation, cough, sneezing.

Incubation period: usually 48 hours.

Contagious period: 24 hours to five days.

Hosts: humans.

Transmission: contact with nasal secretions, airborne droplets generated by sneezing, and contact with contaminated objects.

Because there are a wide variety of rhinoviruses, and because other types of viruses, such as the coronaviruses, the parainfluenza virus, and adenoviruses, may also cause colds, this disease is common. Immunity against colds does not last long.

Treatment of the disease: none.

Geographical distribution of the microorganism: worldwide.

Prevention: regular hand washing.

Vaccine: oral vaccines containing attenuated live viruses exist for some types of cold, but are not generally available, as colds are not usually dangerous.