Prevalence of IgM antibodies to nine Legionella species in Icelandic children.

In order to evaluate the prevalence of antibodies to Legionella species among children in Iceland, a prospective study was conducted in 424 children aged 1 month to 12 years, 28 of whom had an acute respiratory tract infection. Antibody titers to L. pneumophila serogroup 1-6, L. bozemanii, L. dumoffii, and L. micdadei were measured by microagglutination technique. Seroreactivity to Legionella spp. was found in 30% of the children greater than 3 years of age and in 22% of all children. The majority of the children with legionella antibodies had no history of previous or present respiratory tract infection. The children with previous pneumonia or bronchial asthma did not show a higher seroreactivity to legionella than children without such a history. Our observations suggests that Icelandic children are frequently exposed to Legionella species or closely related bacteria.