Mycoplasma pneumonia (MP) is a contagious respiratory infection. Every year almost 2 million Americans are treated for MP. The disease is easily spread through contact with respiratory fluids, and it causes regular epidemics.
The most common sign of infection is a dry cough. Untreated or severe cases can have symptoms affecting the heart and nervous system. In rare cases, MP can be fatal.
Diagnosis is difficult in the early stages of MP because there are few unusual symptoms. As the disease progresses, it can be detected through imaging and laboratory tests. Antibiotics are used to treat MP. Cases unresponsive to antibiotics may need to be treated with intravenous medications.
MP is caused by a bacterium called Mycoplasma pneumoniae. This is the most recognized of all human pathogens—there are over 200 different known species. Most patients with respiratory infection due to M. pneumoniae do not develop pneumonia. Once inside the body, the bacterium may attach itself to lung tissue and multiply until a full infection develops. Most cases are mild and self-limited.
In many healthy adults, the immune system is capable of fighting off MP before it can grow into an infection. Those who are most at risk include:
- elderly people
- people who have immune-compromising diseases (e.g. HIV)
- people who have lung disease
- people who have sickle cell disease
- children younger than age 5
The symptoms of MP are those of a common upper respiratory tract infection.
Common symptoms of MP include:
- persistent fever
- dry cough
In rare cases, the infection may become dangerous and cause damage to the heart or central nervous system. Examples of these disorders include:
- arthritis (disorder in which the joints become inflamed)
- pericarditis (inflammation of the pericardium that surrounds the heart)
- Guillain-Barré syndrome (neurological disorder that can lead to paralysis and death)
- encephalitis (inflammation of the brain)
The disease incubates (silently develops) for the first one to three weeks after exposure. Diagnosis is difficult in the early stages because the body does not instantly reveal an infection. Sometimes manifestations of infection may occur outside the lung. In these cases, signs of infection may include break up of red blood cells, skin rash, joint involvement, and symptoms and signs that indicate of gastrointestinal tract, central nervous system, and heart disease. Three to seven days after the first symptoms appear, medical testing can show evidence of an MP infection.
Tests for the presence of MP include:
- listening to breathing with a stethoscope for abnormalities
- chest X-ray (CXR)
- computed tomography (CT) scan
Although final results may require days or weeks, laboratory tests for MP include:
- serology assay by enzyme linked immunosorbence or polymerase chain reaction
- complement fixation assay for detecting IgM antibodies
MP is a bacterial infection the first line of treatment is antibiotics. Antibiotics must differ for children to avoid any potentially dangerous side effects.
Macrolides, the first choice of antibiotics for children, include:
Antibiotics prescribed for adults include:
Not all people respond to antibiotic treatment. Treatment for those who are unresponsive to antibiotics or complications of illness include corticosteroids:
Severe cases of MP are treated with an immunomodulatory therapy plus antibiotics. An immunomodulatory therapy boosts or decreases the effects of whatever type of medicine it is taken with. Examples of immunomodulatory medication plus antibiotics include:
- corticosteroids with antibiotics
- intravenous Ig (IVIg) plus antibiotics
After treatment most symptoms should subside quickly. Patients can expect a cough to remain the longest. Within two to four weeks, most cases are resolved with no lasting consequences.
People with weak immune systems or chronic infections may struggle to fight off an MP infection. According to the Centers for Disease Control and Prevention (CDC), each year more than 100,000 people in the United States are hospitalized for MP. In some cases, complications develop that can prove fatal (CDC, 2005).
MP peaks in the fall and winter months. During these times, the risk of contracting MP is greatest. This is especially true in schools, daycare centers, and dorms. Close places make it easy for the infection to transmit from person to person.
Here are some tips to lower your risk of infection:
- getting six to eight hours of sleep a night
- eating a balanced diet
- staying away from those who have symptoms of MP
- washing hands before eating or after interacting with sick contacts