Seroepidemiology of Chlamydia pneumoniae in Japan between 1991 and 2000.
OBJECTIVE
To clarify the endemic and epidemic status of Chlamydia pneumoniae in Japan, the incidence of anti-C pneumoniae antibody was evaluated over a period of 10 years.


METHODS
Serum samples were collected from 4756 healthy individuals aged 6 months to 88 years (2488 male and 2268 female individuals) between 1991 and 2000. The antibody titre was determined by a microimmunofluorescence test.


RESULTS
After stratification by age and sex in each year, distinct peaks with prevalences of 73.3% and 73.0% were noted in 1993 and 1999, respectively. The lowest prevalence rate was seen in 1996 (59.0%). The epidemic cycle has been estimated to be almost six years in this geographical area.


CONCLUSIONS
Chlamydia pneumoniae infection is highly endemic in Japan, as it is in Western countries, and there is a year to year variability. Long term studies in Japan are needed to clarify the epidemic occurrence of C pneumoniae infection.
Miyashita
N
N
Division of Respiratory Diseases, Department of Medicine, Kawasaki Medical School, Kurashika City, Okayama, Japan. nao@med.kawasaki-m.ac.jp
Fukano
H
H
Yoshida
K
K
Niki
Y
Y
Matsushima
T
T
D000293:Adolescent; D000328:Adult; D017677:Age Distribution; D000368:Aged; D000369:Aged, 80 and over; D000907:Antibodies, Bacterial / Q000097:blood*; D002648:Child; D002675:Child, Preschool; D023521:Chlamydophila Infections / Q000175:diagnosis / Q000453:epidemiology*; D016993:Chlamydophila pneumoniae / Q000276:immunology*; D004196:Disease Outbreaks; D019353:Endemic Diseases; D005260:Female; D006801:Humans; D015994:Incidence; D007223:Infant; D007564:Japan / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D016036:Seroepidemiologic Studies; D017678:Sex Distribution
D000907:Antibodies, Bacterial