An Asian study on the prevalence of atypical respiratory pathogens in community-acquired pneumonia.
BACKGROUND
In many parts of Asia, the inaccessibility and high cost of diagnostic tests have hampered the study of community-acquired pneumonia (CAP) caused by atypical respiratory pathogens.


OBJECTIVE
This surveillance study examined the frequency of infection with Mycoplasma pneumoniae, Chlamydophila pneumoniae, and Legionella pneumophila in 1756 patients presenting with signs and symptoms of CAP at 12 medical centres in Asia, using standardised laboratory techniques and interpretation criteria in all participating centres.


METHODS
Diagnosis of current infection was based on significant changes in antibody titer or persisting high antibody titers, together with the presence of bacterial DNA in respiratory secretions, in the case of M. pneumoniae and C. pneumoniae infections, or bacterial antigen in urine, in the case of L. pneumophila serogroup 1 infection.


RESULTS
Using these criteria, results from 1374 patients with paired sera showed that, overall, 23.5% of CAP cases were associated with infection with atypical respiratory pathogens, with M. pneumoniae, C. pneumoniae, and L. pneumophila being found in 12.2%, 4.7%, and 6.6% of cases, respectively. Persisting high antibody titers indicative of past exposure to M. pneumoniae, C. pneumoniae, and L. pneumophila were seen in 10.2%, 4.8%, and 18.9% of patients, respectively.


CONCLUSIONS
These data reflect the overall high prevalence of these atypical pathogens among Asian patients with CAP.
Ngeow
Yun-Fong
YF
University Malaya Medical Centre, Petaling Jaya, Malaysia. ngeowyf@ummc.edu.my
Suwanjutha
Subharee
S
Chantarojanasriri
Teerachai
T
Wang
Fu
F
Saniel
Mediadora
M
Alejandria
Marissa
M
Hsueh
Po-Ren
PR
Ping-Ing
Lee
L
Park
Seung-Chul
SC
Sohn
Jang-Wook
JW
Aziah
Ahmad M
AM
Liu
Youning
Y
Seto
Wing-Hong
WH
Ngan
Cecilia C L
CC
Hadiarto
Mangunnegoro
M
Hood
Alsagaff
A
Cheong
Yuet-Meng
YM
D000293:Adolescent; D000328:Adult; D000372:Agglutination Tests; D002648:Child; D002675:Child, Preschool; D016993:Chlamydophila pneumoniae / Q000235:genetics / Q000302:isolation & purification*; D017714:Community-Acquired Infections / Q000175:diagnosis / Q000453:epidemiology* / Q000382:microbiology*; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D005202:Asia, Eastern / Q000453:epidemiology; D005260:Female; D019084:Fluorescent Antibody Technique, Indirect; D006801:Humans; D016952:Legionella pneumophila / Q000302:isolation & purification*; D008297:Male; D008875:Middle Aged; D009177:Mycoplasma pneumoniae / Q000235:genetics / Q000302:isolation & purification*; D018410:Pneumonia, Bacterial / Q000175:diagnosis / Q000453:epidemiology* / Q000382:microbiology*; D016133:Polymerase Chain Reaction; D015995:Prevalence
D004269:DNA, Bacterial