Chlamydia pneumoniae

Chlamydia pneumonia, or Chlamydophila pneumoniae is the most common Chalmydia infection. It is a major cause of pneumonia.

Chlamydia pneumoniae
Scientific classification
Unrecognized taxon (fix):	Chlamydia
Species:	Template:Taxonomy/ChlamydiaC. pneumoniae
Binomial name
Chlamydia pneumoniae Grayston et al. 1989
Synonyms
Chlamydophila pneumoniae (Grayston et al. 1989) Everett, Bush & Andersen 1999

It was originally known as the Taiwan acute respiratory agent (TWAR) from the names of the two original isolates – Taiwan (TW-183) and an acute respiratory isolate named AR-39.

The first known case of infection with C. pneumoniae was a case of conjunctivitis in Taiwan in 1950. There are no known cases of C. pneumoniae in human history before 1950. Originally it was thought to have been caused by a virus.

Reproduction and spread

Chlamydia is a bacteria which spreads person to person. It cannot survive or reproduce on its own. Instead it relies on the energy and resources of the body it lives in, because it is a parasite. It infects and causes disease in humans, including previously healthy people. C. pneumoniae also infects koalas, emerald tree boas (Corallus caninus), iguanas, chameleons, frogs, and turtles.

Symptoms

The illness has two phases (also known as biphasic illness).

Signs and symptoms include inflammation of the lining of the oropharynx (pharyngitis), hoarseness, an ear infection (called otitis), then followed by pneumonia.

This atypical bacterium commonly causes bronchitis, coronary artery disease and atypical pneumonia and several other possible diseases. Chlamydia pneumoniae is thought to be linked to an increased risk of developing lung cancer in the future.

Diagnosis

Usually, patients suspected of having pneumonia will have urine collected to be tested for the bacterial strain causing pneumonia.

Diagnosis is made by the following tests, which are supposed to find the bacteria in bodily samples:

Chlamydia Complement Fixation test (CFT)

PCR test invasive samples are done to test for chlamydia antibodies. Microimmunofluorescence (MIF) tests of serum samples, which is the only serological test that can reliably differentiate chlamydial species.

To describe and identify lung signs, a doctor may use auscultation (they listen with a stethoscope). They listen while the patient is breathing in, and while they are breathing out. They listen to both lungs, at both the chest and the back, starting at the bottom and working their way up. A phlem sample taken from the throat or upper respiratory tract can be used to check for the chlamydia species also.

Chest CT

A scan of the chest to diagnose Chlamydia pnunmonia will often reveal leaking into one side of the lungs alveolar or bronchopneumonia. Many people have both lungs affected. The fluid infiltrate on the scan shows as blocked areas. Most times it's found in a single lobe, more often in the lower lobes than the middle of upper lobe of the lung. Because of its position in the lung, the other symptoms found in tests before a scan is needed will help diagnose alongside a chest CT scan.

A CT scan has a wide spectrum of findings, including: • bronchovascular bundle thickening nodules • pleural effusion • lymphadenopathy (uncommon) • reticular or linear opacities • airway dilatation • pulmonary emphysema It has signs and symptoms similar to other bacterial pneumonias.

Treatment

Doxycycline or Clarithromycin.

Related pages

• chlamydia psittaci
• MERS