Pneumonia, Mycoplasma

BASICS

Bronchopulmonary infection caused by one of several Mycoplasma spp., Mycoplasma pneumoniae being the most common pathogen of the class
Smallest, free-living organism; fastidious and slow-growing; first isolated in cattle in 1898
Most frequently affects children/young adults but can also occur in the elderly; often causes epidemics in close communities (i.e., skilled nursing facilities, dormitories, military barracks)
Infection may be asymptomatic, most often confined to the upper respiratory tract; however, may progress to pneumonia (5–10%) (1)
Course is usually acute with an incubation period of 1 to 4 weeks.
Synonym(s): primary atypical pneumonia (PAP); Eaton agent pneumonia; cold agglutinin–positive pneumonia; walking pneumonia

Pediatric Considerations

Increased incidence of asthma exacerbation in older children
Infants 3 to 6 months with suspected bacterial pneumonia should be hospitalized.

~1 million cases/year in in the United States; annual infection rate of 1% in the United States
20% of community-acquired pneumonia (CAP) requiring hospitalizations annually
Most frequently in autumn/winter seasons.

Predominant sex: male = female
Predominant age group affected: 5 to 20 years
- May occur at any age
- Rare in children <5 years of age
Responsible for up to 15–20% of all cases of CAP yearly
- Most common cause of pneumonia in school children and young adults who do not have a chronic underlying condition

M. pneumoniae is a short-rod mucosal pathogen, which lacks a cell wall and thus not visible on Gram stain.
Can grow under both aerobic and anaerobic conditions
Highly contagious, transmitted by aerosol droplets.
Pathogenicity linked to its filamentous tips, which adhere selectively to respiratory epithelial cell membrane proteins with production of H₂O₂ and superoxide radicals, damaging cilia
Decreased ciliary movement produces prolonged paroxysmal, hacking cough.
Incubation period is 2 to 3 weeks.

ALERT

M. pneumoniae infection may worsen asthma symptoms as well as cause wheezing in children without asthma.
M. pneumoniae infection may worsen chronic obstructive pulmonary disease (COPD) or other chronic pulmonary condition symptoms in adults.

Immunocompromised state (e.g., HIV, transplant recipients, chemotherapy)
Smoking
Close communal living (e.g., military barracks, prisons, hospitals, dormitories, schools, household contacts, skilled nursing facilities)

There's more to see -- the rest of this topic is available only to subscribers.

All content is protected by copyright and may not be used for AI model training or other unauthorized purposes.