Viraemia and antibody response of the mallard (Anas platyrhynchos) to infection with tick-borne encephalitis virus.

The course and intensity of viraemia after experimental infection with a TBE virus was studied in mallards of varying age and weight. Although virus titres in the blood can range from log102.65 to log104.85, in general these titres are believed to be of sufficient magnitude to infect ticks with the virus. Neutralizing antibodies in the serum of ducks are long-lasting and of sufficient titre to prevent a second viraemia. That mallards can play a role in the epidemiology of TBE virus is likely. Although some ducklings died in unexplained circumstances, none of the infected mallards showed overt disease.