Chlamydia Pneumonia

What is Chlamydia Pneumonia?

Pneumonia is a lung infection caused by various types of germs like bacteria, viruses, fungi, and parasites. One type of bacteria that can cause pneumonia is from the Chlamydia family. They are known as C. pneumoniae, C. psittaci, and C. trachomatis. These bacteria usually cause infections in the human respiratory tract, which includes the lungs and breathing tubes.

Most infections caused by C. pneumoniae are symptom-free or only cause mild symptoms, accounting for about 70% of cases. However, in 30% of cases, this bacteria can lead to more serious lung diseases such as atypical community-acquired pneumonia, bronchitis, and upper respiratory tract infections.

Moreover, C. pneumoniae doesn’t just cause respiratory infections. It’s also involved in the development of other inflammatory diseases, including chronic obstructive pulmonary disease (COPD), asthma, lung cancer, and neurological disorders like Alzheimer’s disease, multiple sclerosis, schizophrenia, atherosclerosis (hardening of the arteries), and arthritis.

It’s crucial for healthcare professionals to quickly identify, assess, and effectively treat this condition to prevent complications. The following segment will briefly explain the cause, clinical characteristics, evaluation methods, and treatment approach for a patient with pneumonia caused by Chlamydia bacteria.

What Causes Chlamydia Pneumonia?

Chlamydia pneumoniae, also known as TWAR, is a type of bacteria that belongs to the Chlamydia family. There are three types of Chlamydia that can affect humans: Chlamydia pneumoniae, Chlamydia psittaci, and Chlamydia trachomatis. Both Chlamydia pneumoniae and Chlamydia psittaci can cause infections in our lungs, usually in adults, while Chlamydia trachomatis mainly causes lung infections in children.

Only one type or strain of Chlamydia pneumoniae has been found so far. First discovered in a child in Taiwan in 1965, this bacteria was later found in a student’s respiratory tract before being recognized as a significant cause of lung infections in 1983. Chlamydia pneumoniae can exist in two forms: the elementary body, which can cause infections, and the reticulate body, which is active and can multiply, eventually causing cell damage. It’s important to note that humans are the only known carriers of Chlamydia pneumoniae.

Chlamydia pneumoniae is often involved in community-acquired pneumonia, which is a lung infection you can get outside of a hospital setting. It can pass from person to person through tiny droplets in the air when an infected person coughs or sneezes. What’s interesting is that it can stick around in humid environments, making its spread even easier. It can live in people without causing symptoms, who can still spread it to others. This bacteria usually takes around 3-4 weeks to cause illness, which is longer than most lung infections.

On the other hand, Chlamydia psittaci is usually transmitted through contact with infected birds, particularly if a person inhales the bacteria that can be found in dried bird droppings. It is also possible for this bacteria to spread from person to person.

Lastly, Chlamydia trachomatis pneumonia is passed from an infected mother to her baby during childbirth.

Risk Factors and Frequency for Chlamydia Pneumonia

C. pneumoniae is the most common bacterium that lives inside cells and is mostly linked to respiratory infections. However, it can sometimes cause diseases outside of the lungs too. This pathogen affects most people at some point in their lives, with 50% of people having antibodies to it by the age of 20, and 80% by the time they are 60 to 70 years old. This reveals that people often don’t display symptoms when infected and can be infected multiple times during their life. The presence of these antibodies is more common in males above 15 years old, but it is equal in males and females below this age.

C. pneumoniae infections can be widespread and endemic or epidemic. They cause up to 20% of pneumonia instances that people catch in their communities. In western countries, children and teenagers between the ages of 5 and 15 are most likely to get new infections. People with weakened immune systems can experience severe forms of the infection. The bacteria are also responsible for outbreaks of pneumonia in nursing homes. There is evidence to suggest that C. pneumonia plays a role in the development of asthma and chronic bronchitis, as well as heart disease.

Another type of bacteria, Chlamydia psittaci, is a less common cause of pneumonia, accounting for only about 1% of cases. Each year in the United States, less than 50 cases are reported. These patients typically have been around birds, particularly pet birds or poultry, as these animals are the main source of infection. This disease can also be passed from person to person, but this is rare.

The bacterium C. trachomatis can cause pneumonia in newborns, usually contracted during birth from infected mothers. This usually becomes apparent when the baby is 3 to 12 weeks old, sometimes even sooner.

Signs and Symptoms of Chlamydia Pneumonia

Pneumonia caused by chlamydia often has vague signs and symptoms and can be asymptomatic. It usually appears with mild to moderate respiratory infection symptoms but can be more severe in older individuals, those with a weakened immune system, or individuals with chronic health conditions. The period between exposure to the bacteria and the onset of symptoms is about 3-4 weeks.

The symptoms of chlamydial pneumonia can appear subtly and slowly, which can make it difficult to distinguish from other forms of pneumonia or viral infections. In severe cases, it can lead to respiratory failure and even death. Symptoms may include fever, sore throat, and headache. A cough is typically present a few weeks after the onset of these symptoms, along with shortness of breath and muscle chest pain due to coughing. Other general symptoms such as loss of appetite, nausea, and body aches can also occur. In severe cases, patients may have difficulty breathing, sharp chest pain, drowsiness, or altered awareness. High fever and neck stiffness can mimic meningitis.

• Flu-like symptoms: fever, sore throat, headache
• Cough persisting for several weeks
• Shortness of breath
• Chronic chest pain
• Loss of appetite
• Nausea
• Full body aches
• Difficulty in breathing in severe cases
• Sharp chest pain in severe cases
• Drowsiness/Altered Awareness in severe cases
• High fever and neck stiffness mimicking meningitis

Patients with chlamydia pneumonia may have a history of contact with infected individuals. If the pneumonia is caused by Chlamydia psittaci, there may be a history of exposure to birds or bird feces. In infants, pneumonia caused by Chlamydia trachomatis usually begins subtly without fever and is accompanied by bronchitis.

There may also be signs of infections outside of the respiratory system, although these are less common. Cardiovascular diseases, neurological disorders, and endocrine disorders have all been associated with chlamydial pneumonia. Auscultatory changes are often mild, despite significant abnormalities on X-ray of the lungs. Physical signs of chlamydial pneumonia can include rapid, shallow breathing, elevated body temperature, and signs of upper respiratory tract infections. Wheezing is common. In some cases, observable swelling of liver and spleen can be seen.

Testing for Chlamydia Pneumonia

The early signs of atypical pneumonia can sometimes be vague, so doctors have to be alert and consider this as a possibility whenever a patient presents with certain symptoms. The doctor may have to start treatment based on the symptoms you’re showing, even before having a definite diagnosis.

Your doctor may need to perform a few different blood tests to figure out what’s happening. These could include a complete blood count (measuring all the different types of cells in your blood), liver function tests (checking how well your liver is working), kidney function tests (assessing your kidney health), an erythrocyte sedimentation rate (a test that can indicate inflammation in the body), and serum electrolytes (measuring minerals in your blood). The results can vary – for example, you could have a high, normal, or low count of white blood cells. If you have psittacosis, a type of atypical pneumonia, your liver and kidney test results may be slightly abnormal.

If you have a cough that brings up sputum (a mixture of saliva and mucus), your doctor may want to have this tested to identify any bacteria present and check their resistance to antibiotics. A specific type of bacteria called Chlamydia, which can be involved in pneumonia, can be tested for but this is more challenging as not all labs have this capability.

Then there are specific tests that can tell if you have been infected with Chlamydia. If levels of a certain type of antibody called IgM are high, it indicates a current infection, while high levels of IgG suggest a past infection. For certain species of Chlamydia, tests such as the micro-immunofluorescence test or polymerase chain reaction assay can be used to confirm a diagnosis. Lastly, for a specific species of Chlamydia, they can look for certain features in stained smears obtained from you. Beyond these tests, an assay run on a nasal swab, sputum, or fluid washed out of the airways can be done. However, these tests can be challenging to carry out due to complexities involved.

Alongside these tests, your doctor might order a chest X-ray. The results can sometimes be non-specific and unusual, but it may also show certain characteristic signs, such as a clouding over areas of the lungs. Different patterns can be observed based on the type of pneumonia. It’s also possible for fluid to build up in the space around the lungs, or for parts of the lung to appear more opaque or thicker than usual. Rarely, fluid may build up in the lungs themselves. While different forms of pneumonia can lead to different appearances on an X-ray, knowing these details can help the doctor figure out what’s causing your symptoms.

Treatment Options for Chlamydia Pneumonia

Understanding how severe a disease is can help doctors decide the best treatment approach. In cases of Community-Acquired Pneumonia, or CAP (a type of lung infection), the CURB65 scoring system can be really helpful. It’s handy because it considers a patient’s medical history, physical examination results, and laboratory tests. This makes it a useful tool in primary healthcare settings. The scoring system assesses the following:

• Confusion, especially if it’s new (the person is disoriented about time, place, person)
• Blood urea nitrogen level of more than 19 mg/dL (a measure of kidney function)
• Respiratory rate of 30 breaths per minute or more
• Blood pressure of less than 90 mmHg (systolic) or less than 60 mmHg (diastolic)
• Age of 65 or older

Every factor that fits a patient gives them one point. So, a patient’s score ranges from 0 to 5, and this helps doctors decide the next steps:

• Score 0-1: Further assessment may be needed, but the patient can typically be treated at home
• Score 2: It might be best for the patient to be hospitalized for monitoring and treatment
• Score 3-5: The patient should probably be admitted to the hospital, and they may need to be placed in an intensive care unit (ICU), especially if their score is 4 or 5

In terms of treatment, it can be a little tricky because CAP is often caused by a mixture of different bacteria. Testing can take time, too, so doctors usually start treatment straight away. For patients not in the hospital, they can be given either a macrolide (like azithromycin) or a fluoroquinolone (like moxifloxacin or levofloxacin). Patients who are at higher risk, such as those with lung conditions, those who have recently taken antibiotics, or those in the hospital, are usually given a combination of beta-lactam and a macrolide. But, if these patients are allergic to this combination, they can also be given a respiratory fluoroquinolone.

When it comes to treating specific types of bacterial infections, the Centers for Disease Control and Prevention (CDC) recommends azithromycin and doxycycline as first-line drugs for chlamydial infections. However, the antibiotic of choice may vary depending on the species of the bacteria. For example, if a patient has an infection with C. pneumoniae, they typically receive azithromycin. If C. psittaci is found, they’re usually given tetracyclines like doxycycline. And if the patient is infected with C. trachomatis, erythromycin is usually the drug of choice. There’s also an experimental drug, AZD0914, that might be a good alternative.

Aside from antibiotics, patients are typically advised to take fever-reducing medication, stay hydrated, maintain good hygiene, and rest until recovery.

What else can Chlamydia Pneumonia be?

When a person may have atypical pneumonia caused by Chlamydia pneumoniae, it’s crucial to also think about other causes that might be responsible. These could include Mycoplasma pneumoniae, Francisella tularensis (also known as tularemia), Coxiella burnetii (or Q fever), and Legionella. This means a complete health history and clinical examination should be undertaken to help rule out other potential causes of atypical pneumonia.

Chlamydia can cause more than just pneumonia. It can lead to a broad array of health problems, like bronchitis, pharyngitis, sinusitis, or laryngitis. They often appear with symptoms that are not typical and are fairly mild, so they can easily be misdiagnosed as an upper respiratory tract infection, stomach flu, or a simple throat infection. These symptoms can change depending on the person’s specific case. Among the other possible diagnoses are:

• Bacterial pneumonia
• Fungal pneumonia
• Viral pneumonia
• Tuberculosis
• Influenza

What to expect with Chlamydia Pneumonia

Community-acquired pneumonia (CAP), a type of lung infection, can range from a mild sickness to a severe disease with life-threatening complications. The severity of this illness is connected to a person’s immune system health and the condition of their heart and lungs.

Studies have found that the short-term death rate from CAP is linked to factors such as a patient’s age and other existing health conditions, any abnormalities in lab test results, and the specific cause of the pneumonia. One study revealed that pneumonia caused by the bacterium C. pneumonia had a mortality rate of 9.8%, which was lower than the overall mortality rate of 13.7% for all types of CAP in the same study.

However, the good news is if treatment begins early, the outlook is generally good. A patient with mild symptoms usually recovers within 7 to 10 days of starting treatment. However, some symptoms, such as a dry cough and general weakness, can last longer, delaying complete recovery for 1 week to 2 months. If the disease is not treated, it can worsen, leading to serious complications and potentially even death.

Possible Complications When Diagnosed with Chlamydia Pneumonia

Typically, patients recover without complications. However, those with compromised immune systems could face serious and potentially deadly complications. These complications might include superinfections, or severe infections that occur on top of another infection. For instance, some patients may develop lobar pneumonia, a severe form of pneumonia that can worsen to cause abscesses in the lung, buildup of pus in the lung (empyema), or even septic shock, a life-threatening condition that happens when blood pressure drops to dangerously low levels.

Other possible complications can include severe type 2 respiratory failure, a condition where not enough oxygen is reaching the body’s organs, and acute respiratory distress syndrome, a severe lung condition causing shortness of breath and rapid breathing.

Several long-term complications can also arise from this situation:

• C. pneumoniae, a type of bacteria, can cause asthma and reactive arthritis, a type of arthritis caused by an infection elsewhere in the body.
• In psittacosis, a disease caused by a bacteria that birds often carry, multiple organs can be affected resulting in reduced urine output, leakage of protein into urine, irregular blood clotting, the breakdown of red blood cells, yellowing of the skin and eyes, red patches on the skin, and risks to pregnant women.
• Reiter Syndrome is a late complication that often occurs following a Chlamydia infection. It is marked by a triad of symptoms: reactive arthritis, inflammation of the eye (uveitis), and inflammation of the urethra (urethritis).

C. pneumoniae infection has been observed to expedite the process of arterial wall thickening and atherosclerosis (hardening of the arteries) in animal experiments. There are reports of the infection being associated with other conditions such as lung cancer, arthritis, red lumpy patches on the skin, Alzheimer disease, multiple sclerosis, and sarcoidosis, a disease involving abnormal collections of inflammatory cells in the body.

Preventing Chlamydia Pneumonia

While no vaccines exist to protect against Chlamydia, there are methods to prevent this infection. Patients should consider stopping or significantly reducing their intake of cigarettes and alcohol. It’s also key to practice good respiratory hygiene to minimize the chances of spreading the infection. This includes washing hands regularly, wearing masks, and covering mouths and noses when sneezing or coughing.

If a type of pneumonia caused by chlamydia is not promptly treated, it can be life-threatening. This is especially true for people who are older, have a weakened immune system, or have chronic health issues. If such individuals show signs of respiratory infections, it is essential that they seek medical attention as soon as possible so that they receive timely treatment.

For people with a specific type of Chlamydia called C. psittaci potentially acquired from contact with infected pet birds, they should also consult with a vet. This allows for the birds to be examined and treated if necessary. Additionally, in cases where an infant has another type of Chlamydia infection (C. trachomatis), it’s important that the mother be checked and treated as well, along with her sexual partners. Young women (under 25), and those who are at a higher risk of infection, should be motivated to get tested for Chlamydia to prevent it from being passed on to the baby.