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Volume 40, Number 3, June 2007

Characteristics of Chlamydia trachomatis infection in hospitalized infants with lower respiratory tract infection

Chun-Jen Chen, Keh-Gong Wu, Ren-Bin Tang, Han-Chih Yuan, Wen-Jue Soong, Be-Tau Hwang
Department of Pediatrics, Taipei Veterans General Hospital and National Yang-Ming University, Taipei, Taiwan

Received: May 8, 2006    Revised: June 30, 2006    Accepted: July 20, 2006   


Corresponding author:

Dr. Keh-Gong Wu, Department of Pediatrics, Taipei Veterans General Hospital, 201, Section 2, Shih-Pai Road, Taipei 11217, Taiwan. E-mail: This e-mail address is being protected from spam bots, you need JavaScript enabled to view it



Background and purpose: 

To study the epidemiology, presentation and laboratory findings of Chlamydia trachomatis pneumonia in hospitalized infants younger than 6 months.




Between January 2001 and December 2005, infants younger than 6 months admitted to the children’s medical center of Taipei Veterans General Hospital with the diagnosis of acute bronchiolitis, bronchopneumonia or pneumonia were prospectively studied. Chest radiograph findings were reviewed in all patients. Basic laboratory examinations performed included white blood cell count and eosinophil count. C. trachomatis was detected via enzyme-linked immunosorbent assay antigen test and the titers of immunoglobulin G and immunoglobulin M by indirect immunoperoxidase assay.




A total of 60 infants, 32 males and 28 females, were included. C. trachomatis infection was detected in 30% of patients (18/60). The median age was 2.5 months (range, birth to 6 months). Fever was not detected in 72% of patients (13/18). Only 22% (4/18) of these patients had the characteristic staccato cough. The mean duration of symptoms before admission was 8 days (range, 1 day to 2 months). Rhinorrhea was a prodromal symptom in 67% (12/18) of patients, with a mean pre-onset duration of 7 days (range, 1 to 14 days). Eighty three percent (15/18) of the patients had tachypnea, with a mean duration of 3.2 days (range, 1 to 7 days). Conjunctivitis was noted before admission in 6 patients (33%). Only peripheral eosinophils showed statistically significant difference between Chlamydia-positive and -negative disease (p=0.046), and may be clinically useful in cases of suspected C. trachomatis infection. Mixed infection with other pathogens including adenovirus, respiratory syncytial virus, Mycoplasma pneumoniae, cytomegalovirus and Streptococcus pneumoniae was found in 27% (5/18) of patients.




C. trachomatisis not infrequent and plays an important role in infants younger than 6 months of age hospitalized due to lower respiratory tract infection.



Key words:

Chlamydia trachomatis; Disease transmission, vertical; Hospitalization; Respiratory tract infections



J Microbiol Immunol Infect. 2007;40:255-259.