Seroprevalence of Chlamydia pneumoniae antibodies in preadolescent children in Congo.

Chlamydia pneumoniae (CPn) is recognised as a common cause of both upper an d lower respiratory tract infections. Seroepidemiological studies seem to i ndicate a world-wide distribution of this organism. in order to evaluate th e prevalence of antibodies to CPn in a healthy pediatric population, we mea sured anti-C. pneumoniae antibodies in a group of 253 infants without respi ratory tract infections, aged from 1 to 12 years. Sera were obtained from c hildren seen at immunization clinics and schools in Lubumbashi (Congo). Ant ibodies to CPn were evaluated using micro-immunofluorescence assay. IgG ant ibody to CPn in a titre 16 was considered as positive. The antibody prevale nce was found to be 25.7%. This prevalence was 6.2% in children aged from 1 to 6 years, and 37.8% in children aged from 7 to 12 years. It was less tha n 10% under five years, increasing to 50% at 12 years. The progressive incr easing of seropositivity related to age suggests that reinfections may be f requent. This study shows an important spread of this bacteria in the pread olescent population of an African country.