A URI can be caused by a virus or bacteria, which enter your airway through your nose or mouth and incubate for varying amounts of time before causing an infection. Most URIs are viral infections, such as the rhinovirus, which causes the common cold. They are most common in the fall and winter, but they can happen at any time.
Possible causes of upper respiratory infections include:
- Epstein-Barr virus.
- Human metapneumovirus.
- Parainfluenza virus.
- Respiratory syncytial virus.
- Chlamydia (Chlamydia pneumoniae).
- Diphtheria (Corynebacterium diphtheriae).
- Gonorrhea(Neisseria gonorrhoeae).
- Group A beta-hemolytic streptococci, which causes strep throat.
- Group C beta-hemolytic streptococci.
- Whooping cough (pertussis).
To avoid catching any of these viruses or bacteria, avoid close contact with people in public or who you know are infected. Be mindful to practice good hygiene – especially washing your hands frequently for at least 20 seconds at a time.