Prevalence of antibodies against Legionella spp. in HIV-infected subjects and blood donors

Legionella spp. are considered as opportunistic pathogens causing pneumonia mainly in compromised hosts, in the elderly or in tobacco and/or alcohol addicted. Although immunocompromised patients are also considered at risk for legionellosis, pneumonia by Legionella spp. has been rarely described in AIDS patients.The aim of our study was to determine the prevalence of antibodies to Legionella spp. in HIV-infected subjects in comparison with an healthy population (blood donors).The prevalence of antibodies to Legionella was not associated with the investigated risk factors for legionellosis or with the recording of flu-like symptoms and/or pneumonia in the past five years.To our knowledge, these are the first data that, independently from their interpretation, reveal an unexpected different immunization pattern against Legionella spp. and serogroups in HIV infected individuals with respect to healthy individuals.