Chlamydia pneumoniae is NOT an STD
Chlamydia pneumoniae is not a sexually transmitted disease but rather a respiratory pathogen transmitted directly from person to person through the respiratory tract. 1
Understanding Chlamydia pneumoniae
Chlamydia pneumoniae is a distinct species of Chlamydia that differs from the sexually transmitted Chlamydia trachomatis:
- C. pneumoniae is transmitted through the respiratory route and causes respiratory infections including pneumonia, bronchitis, and sinusitis 2
- It is estimated that approximately 10% of all pneumonias are caused by C. pneumoniae 1
- C. pneumoniae has been associated with chronic inflammatory processes of the respiratory system and has even been suggested to have a connection to coronary heart disease 1
Distinguishing Between Chlamydial Species
It's important to differentiate between the various Chlamydia species as they cause different diseases and have different transmission routes:
- Chlamydia trachomatis is sexually transmitted and infects the columnar epithelium of the cervix, urethra, and rectum, causing the most frequently reported STD in the United States 3
- Chlamydia pneumoniae is transmitted through the respiratory route and is a human pathogen causing respiratory infections 2
- In diagnostic testing, false-positive results can occur with respiratory tract specimens due to cross-reaction of test reagents between C. trachomatis and C. pneumoniae 4
Clinical Manifestations and Treatment
Chlamydia pneumoniae Infections:
- Causes pneumonia, bronchitis, sinusitis, and other acute respiratory infections 2
- Treatment requires high dosage and prolonged course of tetracycline or erythromycin 2
- Most infections are mild, though chronic infections may occur 1
Chlamydia trachomatis Infections (for comparison):
- Causes genital infections that are often asymptomatic 3
- Can lead to pelvic inflammatory disease, infertility, and ectopic pregnancy in women 3
- In infants, C. trachomatis can cause conjunctivitis and pneumonia when exposed during delivery 5
- Treatment of uncomplicated cases involves azithromycin or doxycycline 3
Diagnostic Considerations
When testing for chlamydial infections, it's important to note:
- With respiratory tract specimens, false-positive results can occur because of cross-reaction of test reagents with C. pneumoniae 4
- For C. pneumoniae, specimens should be collected from the respiratory tract 2
- For C. trachomatis (the STD), specimens are collected from genital sites 3
Public Health Implications
Understanding the distinction between these pathogens is important for: