Following reports of death among marine mammals as a result of H5N1 highly pathogenic avian influenza (HPAI) infection in Peru, Chile and Argentina, a report from Uruguay on the Atlantic coast of South America confirms extensive losses in colonies of seals (Otaria byronia).  It is estimated that up to 800 seals may have died based on recovery of 400 carcasses and a 43 percent seropositive rate among sampled animals.

Dr. Carmen Leizagoyen responsible for marine mammals within the Ministry of the Environment stated, “We are hoping that immunity in this species will act against the effects of the virus.”  She stressed the need to conduct whole genome sequencing on isolates obtained from seals that are apparently infected following consumption of dead or moribund marine birds affected by HPAI. This is necessary to monitor for possible mutations indicating the emergence of a zoonotic strain.