| Clinical Features |
Majority with upper respiratory tract infections with fever, cough, malaise, and headache. May lead to tracheobronchitis with fever and nonproductive cough: radiologically confirmed pneumonia develops in 5-10% of cases; rare extrapulmonary syndromes, including cardiologic, neurologic, and dermatologic findings. |
| Etiologic Agent |
Mycoplasma pneumoniae, a small bacterium. |
| Incidence |
Each year an estimated 2 million cases and 100,000 pneumonia-related hospitalizations occur in the United States. |
| Sequelae |
Persistent cough is common during convalescence; other sequelae are rare. Fatal cases are reported occasionally, primarily among the elderly and persons with sickle-cell disease. |
| Transmission |
Person-to-person transmission by contact with respiratory secretions. Incubation period is 1 to 4 weeks. |
| Risk Groups |
Persons of all ages are at risk but rarely children less than 5 years old. It is the leading cause of pneumonia in school-age children and young adults. Outbreaks can occur especially in crowded military and institutional (e.g., college) settings. Outbreaks in these settings can last several months. |
| Surveillance |
No national surveillance system exists. |
| Trends |
Unknown. However, with improved diagnostic testing, more cases may be identified. |
| Challenges |
Diagnosis of acute infections remains difficult; therefore, early recognition of outbreaks has been problematic. Challenge: prevent secondary cases in outbreak by prompt initiation of control measures. |
| Opportunities |
Basic diagnostic strategy in clinical practice includes serology and standard polymerase chain reaction (PCR). New diagnostic techniques (PCR-related methods) may enable more rapid diagnosis. Exploration of the role of M. pneumoniae in community-acquired pneumonia and as a potential cofactor in severe pneumonia. |
