Impact of Annual Bacterial Epizootics on Albatross Population on a Remote Island

AbstractThe reduced species richness typical of oceanic islands provides an interesting environmental setup to examinein natura the epidemiological dynamics of infectious agents with potential implications for public health and/or conservation. On Amsterdam Island (Indian Ocean), recurrent die-offs of Indian yellow-nosed albatross (Thalassarche carteri) nestlings have been attributed to avian cholera, caused by the bacteriumPasteurella multocida. In order to help implementing efficient measures for the control of this disease, it is critical to better understand the local epidemiology ofP. multocida and to examine its inter- and intra-annual infection dynamics. We evaluated the infection status of 264 yellow-nosed albatrosses over four successive breeding seasons using a real-time PCR targetingP. multocida DNA from cloacal swabs. Infection prevalence patterns revealed an intense circulation ofP. multocida throughout the survey, with a steady but variable increase in infection prevalence within each breeding season. These epizootics were associated with massive nestling dies-offs, inducing very low fledging successes ( ≤ 20%). These results suggest important variations in the transmission dynamics of this pathogen. These findings and the developed PCR protocol have direct applications to guide future research and refine conservation plans aiming at controlling the disease.

Source: EcoHealth - July 22, 2020 Category: Environmental Health Source Type: research