Clinical Features of Chlamydia pneumoniae Infection

Key points

  • Chlamydia pneumoniae infections can occur in the upper or lower respiratory tract.
  • Infections can be asymptomatic, while those with symptoms have a wide clinical presentation.
  • Complications are rare but can be serious.
Healthcare provider assists a young boy with his asthma medication

Clinical features

Most respiratory infections caused by C. pneumoniae are asymptomatic or mild.

For those with symptoms, clinical presentations can vary widely.

Most common

People with symptoms of C. pneumoniae infection most commonly present with

  • Cough
  • Fever
  • Headache
  • Malaise

Less common

They also can develop:

  • Coryza
  • Laryngitis
  • Pharyngitis
  • Pneumonia

Extended, persistent course of illness

After gradual illness onset, symptoms due to C. pneumoniae respiratory infection may continue over extended periods. Patients may experience a persistent cough and malaise for several weeks or months despite appropriate antibiotic therapy. C. pneumoniae can cause chronic infection.

Complications

Although rare, severe complications can occur. These severe complications can result in hospitalization and sometimes death.

Complications include:

  • Encephalitis
  • Exacerbation of asthma
  • Myocarditis

Potential link with other diseases

In the past 20 years, researchers have linked a wide variety of diseases to C. pneumoniae infection including:

  • Age-related macular degeneration
  • Alzheimer's disease
  • Asthma
  • Atherosclerotic cardiovascular disease
  • Chronic fatigue syndrome
  • Chronic skin wounds
  • Multiple sclerosis

However, researchers have not been able to confirm a causal relationship between these diseases and C. pneumoniae infection.

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Content Source:
National Center for Immunization and Respiratory Diseases; Division of Bacterial Diseases