Atypical pneumonia is usually caused by certain bacteria such as mycoplasma pneumoniae, chlamydophila pneumoniae and legionella pneumophila. Mostly atypical pneumonia is milder form of pneumonia; however, pneumonia caused by legionella, in particular, can cause acute case that can also lead to high mortality rate.
Atypical pneumonia, unfortunately, does not respond to the usual antibiotic treatment. Though it is caused by bacteria (mycoplasma pneumoniae, chlamydia pneumoniae, legionella pneumophila and bordatella pertussis), viruses like influenza and coronaviruses are known to cause atypical pneumonia. Normally, this type of infection is not as severe as the conventional pneumonia, but legionnaire disease (legionella pneumophila) kills up to 50% of its victims if left untreated. The deadly SARS virus, which made its presence felt only recently, is a new coronavirus that causes atypical pneumonia.
Atypical pneumonia (mycoplasma and chlamydophila) are mild and are characterized by a more drawn out course of symptoms. Mycoplasma pneumonia often affects young people and it has symptoms that are usually outside of the lungs. Some of the symptoms are anemia and rashes, and neurological syndromes such as meningitis, myelitis, and encephalitis. The severe forms of mycoplasma pneumonia have been seen in all age groups. Chlamydophila pneumonia occurs throughout the year and contributes to 5-15% of all pneumonia cases. It is a milder form of pneumonia with a low mortality rate. In contrast, atypical pneumonia caused by legionella accounts for 2-6% of the total pneumonia cases and has a higher mortality rate. Elderly individuals who have underlying diseases, smokers, and people with chronic illnesses and immunocompromised people are at higher risk of contracting this type of pneumonia. Pneumonia due to legionella can also be contracted through contact with contaminated aerosol systems like infected air-conditioning systems.
The probability of contracting atypical pneumonia depends on the patient and the patientís environment. For instance, chlamydia and mycoplasma pneumonias are spread by close contact in places that are crowded like military barracks or college dormitories. Chronic illnesses, especially respiratory illnesses (i.e. bronchitis, emphysema, COPD), and a history of smoking are other factors that predispose individuals to atypical pneumonias. Use of chronic immunosuppressants like steroids is known to make people more susceptible to the infection.
The best method to treat atypical pneumonia is antibiotic therapy. Mild cases can be treated at home by administering oral antibiotics. However, severe cases, especially the ones caused by legionella may need one to take intravenous antibiotics and oxygen supplementation. Antibiotics that are known to be active against these organisms include - erythromycin, clarithromycin, azithromycin, fluoroquinolones and their derivatives (such as levofloxacin), and tetracyclines (such as doxycycline).
Atypical Pneumonia Causes
Atypical Pneumonia Symptoms
Atypical Pneumonia Diagnosis and Treatment