12.1: Viral Infections of the Respiratory Tract
- Identify the most common viruses that can cause infections of the upper and lower respiratory tract
- Compare the major characteristics of specific viral diseases of the respiratory tract
Viruses are the most frequent cause of respiratory tract infections. Unlike the bacterial pathogens, we have few effective therapies to combat viral respiratory infections. Fortunately, many of these diseases are mild and self-limiting. A few respiratory infections manifest their primary symptoms at other locations in the body.
The Common Cold
Influenza
Key Concepts and Summary
- Viruses cause respiratory tract infections more frequently than bacteria, and most viral infections lead to mild symptoms.
- The common cold can be caused by more than 200 viruses, typically rhinoviruses, coronaviruses, and adenoviruses, transmitted by direct contact, aerosols, or environmental surfaces.
- Due to its ability to rapidly mutate through antigenic drift and antigenic shift , influenza remains an important threat to human health. Two new influenza vaccines are developed annually.