Key points
- Bacteria called Chlamydia pneumoniae can cause respiratory tract infections.
- The bacteria are spread through respiratory droplets by coughing and sneezing.
- C. pneumoniae usually affect people for the first time as school-aged children or young adults.
- Reinfection and severe disease are most common in adults 65 years or older.
Causes
C. pneumoniae are bacteria that can cause respiratory tract infections. They damage the lining of the respiratory tract including the throat, windpipe, and lungs.
How the bacteria spread
People spread C. pneumoniae by coughing or sneezing, which creates small respiratory droplets that contain the bacteria. Other people can get infected if they breathe in those droplets. People can also get sick if they touch something with those droplets and then touch their mouth or nose.
Risk factors
Age
People of all ages can get sick from C. pneumoniae.
First infection: It most commonly infects people for the first time when they are school-aged children or young adults.
Reinfection is most common in adults 65 years or older.
Severe infections and age
Adults 65 years or older are at increased risk for severe disease caused by C. pneumoniae infection, including pneumonia.
Crowded settings
People at increased risk include those who live or work in crowded settings where outbreaks most commonly occur, such as:
- College residence halls
- Detention or correctional facilities
- Hospitals
- Long-term care settings
- Military training facilities
- Schools