A number of the viruses that cause the common cold may also result in asymptomatic infections.

An example of an asymptomatic infection is a mild common cold that is not noticed by the infected individual.

Onset time is highly variable and the average asymptomatic infection persists for over a year.

"It becomes difficult if there are a significant number of asymptomatic infections," he said.

Adults in stable endemic areas usually experience asymptomatic or milder infections.

For example, billions of people around the world have asymptomatic infections of M. tuberculosis.

For a complete list of asymptomatic infections see subclinical infection.

Clinical manifestations range from asymptomatic infection to severe illness.

Evidence of such asymptomatic infections can be detected by blood tests.

Overall, human histoplasmosis is considered usually to be an asymptomatic and clinically insignificant infection.