Study of emerging infectious diseases in marine mammals in Brazil: brucellosis, morbillivirosis and coronavirus, including the investigation of SARS-Cov-2

Abstract

Aquatic mammals are considered sentinels of the health of the ecosystems they inhabit and, therefore, of human and animal health, indicating the presence of pathogens, degradation and changes in the environment. Several pathogens have been reported in aquatic mammals in the Brazilian coast. Infections with Brucella have been demonstrated in several cetacean species associated with stranding and mortality. Morbillivirus infections have also been reported in cetaceans, being associated with mass mortality. Despite the importance of these infections, several issues related to their immunopathogenesis and epidemiology need to be clarified. Coronavirus infection has not being investigated in marine mammals in Brazil, but there are reports of infections in cetaceans in the United States and Europe. The emergence and global spread of SARS-CoV-2, which causes COVID-19, imposes new health risks with unpredictable consequences in the context of one health. In view of the high potential for environmental contamination and the plasticity of coronaviruses, with risk of interspecies transmission and adaptation to new hosts, the monitoring of the infection in wildlife is an urgent measure. Due to the emerging character of these infections, their importance for the conservation of aquatic mammals and the role of these animals as health sentinels of marine ecosystems, this proposal has the following objectives: (1) to evaluate the occurrence of Brucella, morbillivirus and coronavirus infections in cetaceans and pinnipeds on the Brazilian coast, expanding the area to be monitored in relation to previous studies and characterizing the detected pathogens; (2) to identify the pathological processes associated with the infections. Tissues and sera will be collected during the period of 2020-2022 and analysed using serological, molecular and microbiological tests to detect the listed pathogens. The phenotypic and molecular characterization (by sequencing of specific genes or by the complete genome sequencing) of the positive samples will be conducted when applicable. The results obtained may help to elucidate important epidemiological issues of these infections in the Brazilian territory and to contribute to the conservation of the marine mammals and the maintenance of animal and human health. (AU)