Infections with Legionella pneumophila in Children

Abstract

To learn the role of Legionella pneumophila, the agent of Legionnaires' disease, in childhood illness, a prospective study was conducted among 52 children younger than four years of age with acute disease of the lower respiratory tract. Viral, mycoplasmal, and bacterial cultures and acute- and convalescent-phase sera were obtained during 64 episodes of acute illness; additional sera were drawn annually for three to five years. On the basis of serologic evidence, none of the acute episodes appeared to be due to L. pneumophila serogroup 1 or 2. However, examination of annual serum specimens showed that 27 (52%) of the children had rises in titer of indirect immunofluorescent antibody (a fourfold or greater rise to a reciprocal titer of greater than or equal to 128). Most rises in titer were in response to the serogroup 2 antigen. These results suggest that L. pneumophila is not a common cause of acute respiratory disease in early childhood in the study area but that children are frequently exposed to the organism. Alternatively, the serologic responses might be to unrelated cross-reacting microorganisms.

Pontiac Fever Associated With a Whirlpool Spa

“…Similarly, Anderson et al (18) found that 27 (52 per cent) of 52 children followed annually had diagnostic rises to Legionnaires' disease titers without any relation to the development of pneumonia, and they concluded that the "majority of exposure resulted either in sub-clinical infection or atypical illness. Of interest is the possible increase in titers to L. pneumophila, serogroup 6, in those employees working at the inn for 5=6 months.…”

Cavitary Legionellosis in Two Immunocompetent Infants

“…A serologic study of 52 children with lower respiratory tract disease by Andersen et al 23 showed that more than half of these children had a fourfold or greater rise in antibody titer over a period of time, but that this was not associated with an acute illness. However, serologic studies may give misleading results because many children without clinical evidence of legionellosis have been shown to have positive legionella titers and seroconversion may not occur until late in the course of disease.…”

Serological evidence ofLegionellaspecies infection in acute exacerbation of COPD

“…The concept of unreliable specificity of immunofluorescent antibody (IFA) for diagnosing clinically relevant infections by Legionella is also supported by some studies. ANDERSEN et al [9] found a clinically silent four-fold indirect IFA seroconversion in their prospective study on annual (3-5 yrs) serum specimens among 52 children, more than 20-yrs ago. More recently, a four-fold IFA asymptomatic seroconversion has also occasionally been observed in high-risk populations such as adult renal transplantation patients [10].…”