Mycoplasma pneumoniae, often referred to as “walking pneumonia,” is a common respiratory infection. A frequent question is whether individuals can contract this infection more than once.
What is Mycoplasma Pneumonia?
Mycoplasma pneumoniae is a bacterium responsible for respiratory infections, including upper respiratory tract infections, bronchitis, and pneumonia. The infection commonly manifests with symptoms such as a persistent dry cough, sore throat, headache, fever, and fatigue. While it can lead to pneumonia, “walking pneumonia” highlights its generally milder course compared to other forms, often not requiring hospitalization.
This bacterium spreads through respiratory droplets released when an infected person coughs or sneezes. Transmission usually requires close or prolonged contact. Symptoms typically appear one to four weeks after exposure and can last for several weeks.
Immunity and Reinfection Risk
After an initial Mycoplasma pneumoniae infection, individuals typically develop some level of immunity. However, this immunity is not lifelong and may not offer complete protection against future infections. Research indicates that antibody levels, which are markers of immunity, can remain elevated for two to nine years after pneumonia, but often decline sharply after the second year in people with milder symptoms.
The partial and declining effectiveness of the immune response means individuals can become susceptible again, making it possible to get Mycoplasma pneumoniae more than once. While second infections are known to occur, they may sometimes be milder than the initial episode.
Factors Affecting Second Infections
The waning of protective antibodies over time is a primary reason, as the immune system’s memory against the specific strain may diminish. Another element is the existence of different strains or subtypes of Mycoplasma pneumoniae.
An infection with one strain might not provide full protection against another, allowing for reinfection with a different variant. Individual variations in immune response also play a role, as some people may develop a stronger or longer-lasting immunity than others.
A weakened immune system, whether due to other illnesses, medical conditions, or certain treatments, can increase susceptibility to reinfection. People recovering from another respiratory viral illness or those with pre-existing lung conditions are also at higher risk for serious infections. Living in crowded environments like schools or dormitories can further increase the risk of exposure and subsequent infection.
Recognizing and Treating Recurrence
Symptoms of a second Mycoplasma pneumoniae infection might be similar to the initial episode, or they could vary in severity. Common signs include a persistent dry cough, fever, sore throat, and fatigue. It is important to consult a healthcare provider for proper diagnosis, as self-diagnosis can be misleading.
Diagnosis typically involves a medical evaluation of symptoms and may include specific tests to confirm the presence of Mycoplasma pneumoniae. These tests can include nucleic acid amplification tests (NAATs), such as PCR. Blood tests or chest X-rays may also be used to aid in diagnosis.
Treatment for Mycoplasma pneumoniae usually involves antibiotics, particularly macrolides, tetracyclines, or fluoroquinolones. It is important to complete the entire course of antibiotics, even if symptoms improve, to ensure the infection is fully cleared and to help prevent antibiotic resistance. While many mild cases may resolve without medication, seeking medical advice is crucial for appropriate treatment and management, especially for recurrent infections or severe symptoms.