| Clinical
Features |
Pneumonia or bronchitis, gradual
onset of cough with little or no fever. Less common presentations
are pharyngitis, laryngitis, and sinusitis. |
| Etiologic
Agent |
Chlamydia pneumoniae. This
bacterium was recognized in 1983 as a respiratory pathogen,
after isolation from a college student with pharyngitis. |
| Incidence |
Each year an estimated 50,000 adults
are hospitalized with pneumonia in the United States. The
overall incidence is unknown. |
| Sequelae |
C. pneumoniae infection may
be associated with atherosclerotic vascular disease. Associations
with Alzheimers disease, asthma, and reactive arthritis have
been proposed. |
| Transmission |
Person-to-person transmission by
respiratory secretions. |
| Risk
Groups |
All ages at risk but most common
in school-age children. By age 20 years, 50% of population
have evidence of past infection. Reinfection throughout life
appears to be common. |
| Surveillance |
No national or state surveillance
exists. Multicenter study of etiologies of community-acquired
pneumonia is ongoing. |
| Trends |
Unknown. Improved diagnostic testing
may lead to improved recognition of infection. |
| Challenges |
Isolation of the etiologic agent
is difficult and paired acute- and convalescent-phase sera
are required to confirm the diagnosis using antibody tests.
There are no known methods to prevent infection or possible
sequelae. The Helvetica" size="-2">Centers
for Disease Control and Prevention
National
Center for Infectious Diseases
Division
of Bacterial and Mycotic Diseases
|
|
