Eight-week-old golden hamsters (Mesocricetus auratus, Janvier, France) were anesthetized and infected intraperitoneally (i.p.) with 0.4 ml of wild-type NiV (10 000 PFU) in the BSL-4 laboratory in Lyon. Each day post infection (p.i.), one hamster was euthanised and organs were frozen at 280uC.