Westbury et al in 1995 reported resistance of mice to HeV infection in a study that was designed to identify a suitable laboratory animal model of HeV disease. Juvenile BALB/c mice were inoculated with 5000 median tissue culture infective doses (TCID 50 ) of virus by a parenteral route and observed for clinical signs of infection. Mice remained clinically well throughout the 21 day study period and, after euthanasia, there was no evidence of infection by gross or histological examination, virus isolation or serology. Similar results were reported by Wong et al in 2003, who investigated the susceptibility of mice to the closely related Nipah virus [21] by inoculating juvenile Swiss brown mice by either parenteral or intranasal routes.