Illness and otological changes during upper respiratory virus infection

Area of Science:

• Virology
• Epidemiology
• Otolaryngology

Background:

• Upper respiratory virus infections can lead to complications in adjacent anatomical areas.
• Epidemiological studies often calculate complication frequency based on symptomatic individuals, potentially skewing results.
• Infected individuals who do not exhibit symptoms may still develop complications.

Purpose of the Study:

• To quantify the presentation bias in estimating complication frequency during controlled viral upper respiratory infections.
• To assess the relationship between illness and otological complications in experimentally induced infections.

Main Methods:

• A prospective, experimental study involving 316 adult volunteers.
• Volunteers were experimentally infected with rhinovirus (types 39 and hanks) or influenza A virus.
• Data on illness, abnormal middle ear pressure, and middle ear pressure without illness were analyzed.

Main Results:

• Approximately 50% of infected subjects reported illness across all three viruses.
• While symptomatic individuals had a higher rate of abnormal middle ear pressure, about one-third of those with this complication did not report illness.
• This indicates that a substantial portion of complications occur in asymptomatic or minimally symptomatic individuals.

Conclusions:

• Epidemiological surveys likely underestimate the true incidence of complications from viral upper respiratory infections due to presentation bias.
• A significant number of complications arise in individuals not classified as ill.
• Further research should account for asymptomatic cases to accurately determine complication rates.