Brown pelicans (Pelecanus occidentalis) are becoming increasingly common visitors to
rehabilitation facilities due to entanglement in fishing lines and hooks. As such, it is important to establish baseline
medical data, including diseases with zoonotic potential, for accurate health assessment of this species. The purpose of
this study was to survey brown pelicans in south Florida for prevalence of antibodies to common avian diseases. Blood and
feces were sampled between October 1998 and January 1999 from 31 healthy but permanently flightless pelicans and 48 wild
caught healthy pelicans from a rehabilitation facility on the east coast of Florida. Serologic tests of healthy birds
indicated 79% of pelicans were seropositive for Chlamydia antibodies. Enzyme-linked immunosorbent assays (ELISA) on
a subset of these birds were positive for Chlamydia antigen in 89% of birds. However, Chlamydia DNA probe
tests were all negative. Pelicans were also seropositive for Aspergillus antibody (75%) and Sarcocystis
antibody (54%). Seroconversion was rare for Mycobacterium (11%) and non-existent for Newcastle's disease virus.
Overall, the level of seroconversion was great, however antigen detection and/or shedding was low. As these pelicans
routinely come in contact with veterinarians, zookeepers, and rehabilitators, the potential for disease transmission
places immunocompromised individuals at increased risk. In light of the zoonotic potential of chlamydiosis and
aspergillosis, more studies are needed to elucidate conditions for active shedding and for health assessments of other
seabird species as potential carriers of these and other zoonotic diseases.