Pneumonia Chlamydial
Chlamydia pneumoniae is a type of bacteria that can cause respiratory infections ranging from mild cold-like symptoms to more serious pneumonia, though most people recover on their own without treatment.
Table of contents
- What it is
- Other names
- Types of infections
- Causes and how it spreads
- Symptoms
- Who is at risk
- Complications
- Testing and diagnosis
- Treatment and recovery
- Prevention
What it is
Chlamydia pneumoniae is a type of bacteria that can cause respiratory tract infections. These bacteria are different from the bacteria that cause sexually transmitted infections.[1] The bacteria cause illness by damaging the lining of the respiratory tract, including the throat, windpipe, and lungs.[1]
These bacteria are special because they can only survive and reproduce inside other cells. Scientists call them obligate intracellular bacteria, meaning they must live inside a host cell to multiply.[2] The bacteria exist in two different forms: the elementary body, which can infect new cells but cannot reproduce, and the reticulate body, which can multiply inside cells but cannot spread to new hosts.[3]
Humans are the only known carriers of Chlamydia pneumoniae bacteria.[2]
Other names
Chlamydophila pneumoniae, TWAR
Scientists previously called these bacteria Chlamydophila pneumoniae. The name TWAR comes from the two original isolates identified in Taiwan and an acute respiratory sample designated AR-39.[1][3]
Types of infections
Chlamydia pneumoniae most commonly causes upper respiratory tract infections. These can include ear infections, sinus infections, and sore throats.[1]
The bacteria can also cause lower respiratory tract infections. These include bronchitis, which is inflammation or swelling of the airways to the lungs, and pneumonia, which is a lung infection.[1] People with pneumonia caused by Chlamydia pneumoniae are more likely to have laryngitis, which occurs when the voice box becomes inflamed or swollen, compared to other types of bacterial pneumonia.[1]
Most respiratory tract infections caused by Chlamydia pneumoniae are either without symptoms or cause only mild symptoms. This accounts for about 70% of cases. However, in 30% of cases, the bacteria can lead to more serious respiratory illnesses such as community-acquired pneumonia with unusual symptoms, bronchitis, and upper respiratory tract infections.[2]
Causes and how it spreads
People spread Chlamydia pneumoniae by coughing or sneezing, which creates small respiratory droplets that contain the bacteria.[5] 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.[4]
The bacteria can survive in humid environments, making their spread easier. They can live in people without causing symptoms, and these people can still spread the infection to others.[2]
Symptoms
It can take 3 to 4 weeks for symptoms to appear after someone has been exposed to the bacteria. This is longer than most respiratory infections. Some people may become infected and have no symptoms.[1]
Symptoms of Chlamydia pneumoniae usually begin slowly. They may start with a sore throat, followed by a cough after a week or more. The cough may last for 2 to 6 weeks.[4]
For those with symptoms, the most common ones include:
- Fatigue or 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.[1]
Who is at risk
People of all ages can get sick from Chlamydia pneumoniae. The bacteria most commonly infect people for the first time when they are school-aged children or young adults.[5] The infections are common in school-aged children and young adults.[4]
By the age of 20, about 50% of people have antibodies to this bacteria, and by ages 60 to 70, about 80% have these antibodies. This reveals that people often don’t display symptoms when infected and can be infected multiple times during their life.[2]
Reinfection is most common in older adults. Adults 65 years or older are at increased risk for severe disease caused by Chlamydia pneumoniae infection, including pneumonia.[5]
People at increased risk include those who live or work in crowded settings where outbreaks most commonly occur. These settings include college residence halls, detention or correctional facilities, hospitals, long-term care settings, military training facilities, and schools.[5]
Complications
While uncommon, serious complications can occur with Chlamydia pneumoniae infections. These include:
- Encephalitis, which is swelling in the brain
- Myocarditis, which is swelling of the heart
- Worsening asthma
Chlamydia pneumoniae can cause chronic or long-lasting infections.[1]
Some experts think that chronic Chlamydia pneumoniae infection might contribute to conditions like arthritis, asthma, and atherosclerosis, which is plaque buildup in blood vessels. The bacteria is also involved in the development of multiple inflammatory conditions including chronic obstructive pulmonary disease (COPD), lung cancer, and neurological disorders such as Alzheimer’s disease, multiple sclerosis, and schizophrenia.[1][2]
Testing and diagnosis
Healthcare providers may test to see if a patient has a Chlamydia pneumoniae infection with a laboratory test. The laboratory test involves taking a sample of sputum, which is phlegm, or swabbing the nose or throat.[1]
When possible, specimens should be collected before starting antibiotic treatment. Culture and molecular test methods are more likely to detect Chlamydia pneumoniae when specimen collection occurs before antimicrobial therapy starts.[9]
Clinical reference laboratories can provide diagnostic testing for Chlamydia pneumoniae infections using molecular methods, serology, and culture. There are multiple commercially available systems for the direct detection of Chlamydia pneumoniae in respiratory specimens, including several tests cleared by the Food and Drug Administration.[9]
Since the COVID pandemic, it has become more common for doctors to use a panel test that can look for other viruses or bacteria too. This has led to earlier and faster diagnosis of Chlamydia pneumoniae infections.[4]
Treatment and recovery
Most people will recover on their own without medicine. However, antibiotics are sometimes needed.[1] Illness caused by Chlamydia pneumoniae is usually self-limiting, meaning people may not seek care.[9]
Healthcare providers can use several types of antibiotics to treat Chlamydia pneumoniae infections. If a healthcare provider diagnoses someone with this infection, they will decide the best treatment.[1]
Antibiotic options include macrolides such as azithromycin, which is first-line therapy, tetracyclines including tetracycline and doxycycline, and fluoroquinolones. Healthcare providers shouldn’t prescribe tetracyclines for young children under normal circumstances.[9]
Chlamydia pneumoniae show resistance to certain antibiotics, which aren’t recommended for treatment. These include penicillin, ampicillin, and sulfa drugs.[9]
Recovery from the infection may be slow.[4] Symptoms of Chlamydia pneumoniae infection can reappear after a short or conventional course of antibiotics. Persistent infection after treatment has been demonstrated by recovery of viable bacteria; therefore, a secondary course of treatment may be recommended.[9]
Prevention
People can get a Chlamydia pneumoniae infection more than once. There is no vaccine to prevent Chlamydia pneumoniae infection.[1] Healthcare providers generally don’t prescribe antibiotics after exposure to help prevent someone from getting this infection.[1]
However, there are steps people can take to help protect themselves and others. Good hygiene is the best way to prevent the bacteria’s spread. Covering coughs and sneezes and keeping hands clean can help prevent the spread of respiratory germs, including Chlamydia pneumoniae.[1]
The best way to keep from getting or spreading Chlamydia pneumoniae is to wash your hands often. This is especially important after coughing or sneezing.[1]
