Prevalence of Legionella pneumophila infection in children and its role in pediatric community-acquired atypical pneumonia.

The infection status of Legionella pneumophila in children and its role in pediatric community-acquired pneumonia were investigated. Because exposure to Legionella pneumophila may be highly variable and there has been no unanimously agreed-upon cut-off values in previous seroprevalence studies, 60 serum samples collected from infants aged 12 to 18 months were examined using immunofluorescence antibody test to determine the cut-off titer which represents past Legionella pneumophila infection. An IFA titer of greater than or equal to 32 was found to be suitable to represent past L. pneumophila infection. A seroepidemiological study of the prevalence of L. pneumophila in 180 children showed the prevalences in children aged 7 to 18 years to be between 28.4 and 35%. Fifty-three paired sera were tested to determine the role of Legionella pneumophila in pediatric, community-acquired, atypical pneumonia. The frequency of confirmed disease was 0% and of presumptive cases was 5.7%. Legionella pneumophila was not a common etiologic agent of pediatric pneumonia in Taiwan.