About Chlamydia pneumoniae Infection

Key points

  • Bacteria called Chlamydia pneumoniae can cause respiratory tract infections.
  • These infections are generally mild, but serious complications can develop.
  • Most people will recover on their own without medicine, but antibiotics are sometimes needed.
  • Good hygiene, including handwashing, is the best way to prevent the bacteria's spread.
A female young adult sneezing or coughing with a blanket wrapped around her shoulders

What it is

C. pneumoniae are a type of bacteria that can cause respiratory tract infections. The bacteria cause illness by damaging the lining of the respiratory tract, including the throat, windpipe, and lungs.

Previously, scientists called the bacteria Chlamydophila pneumoniae.

A computer-generated image of Chlamydia pneumoniae bacteria.
This image of Chlamydia pneumoniae was computer generated.

Types

C. pneumoniae most commonly cause upper respiratory tract infections, which can include

  • Ear infections
  • Sinus infections
  • Sore throats

C. pneumoniae can also cause lower respiratory tract infections, like bronchitis and pneumonia. Compared to other types of bacterial pneumonia, people with pneumonia caused by C. pneumoniae are more likely to have laryngitis.

  • Bronchitis is inflammation (swelling) of the airways to the lungs.
  • Laryngitis is when the voice box becomes inflamed or swollen.
  • Pneumonia is a lung infection.

Symptoms

It can take 3 to 4 weeks for symptoms to appear after someone has been exposed to the bacteria. Some people may become infected and have no symptoms.

For those with symptoms, the most common symptoms of C. pneumoniae infection include

  • Fatigue (feeling tired)
  • Headache
  • Hoarseness, weak voice, or loss of voice
  • Low-grade fever
  • Runny or stuffy nose
  • Sore throat
  • Slowly worsening cough

Symptoms can continue for several weeks after they start.

Complications

While uncommon, serious complications can occur:

  • Encephalitis (swelling in the brain)
  • Myocarditis (swelling of the heart)
  • Worsening asthma

C. pneumoniae can cause chronic (long) infections. Some experts think that chronic C. pneumoniae infection might contribute to conditions like

  • Arthritis
  • Asthma
  • Atherosclerosis (plaque buildup in blood vessels)

Who is at risk

Some people are more likely to get infected with C. pneumoniae than others.

Keep Reading: Risk Factors

Causes

C. pneumoniae infections are caused by bacteria that people spread through coughing or sneezing.

Keep Reading: Causes and Spread

Prevention

People can get a C. pneumoniae infection more than once.

There is no vaccine to prevent C. pneumoniae infection. Healthcare providers generally don't prescribe antibiotics after exposure to help prevent someone from getting a C. pneumoniae infection.

However, there are steps people can take to help protect themselves and others.

Good hygiene

Covering coughs and sneezes and keeping hands clean can help prevent the spread of respiratory germs, including C. pneumoniae.

Stop germs! Wash your hands‎

The best way to keep from getting or spreading C. pneumoniae is to wash your hands often. This is especially important after coughing or sneezing.

Testing and diagnosis

Healthcare providers may test to see if a patient has C. pneumoniae infection with a laboratory test. The laboratory test involves taking a sample of sputum (phlegm) or swabbing the nose or throat.

Treatment and recovery

Healthcare providers can use several types of antibiotics to treat C. pneumoniae infections. However, most people will recover on their own without medicine. If a healthcare provider diagnoses someone with a C. pneumoniae infection, they will decide the best treatment.