RVFV can be transmitted through injection of infectious saliva from mosquito into the dermis or direct inhalation from body fluids, such as blood of infected animals [2, 3] . To approximate these two natural routes of infection and to monitor their effects, we compared the light production after intraperitoneal, intradermal or intranasal inoculation of 10 4 PFU rZHDNSs-hRLuc into Ifnar1 2/2 mice. Following intradermal inoculation of the ear pinna (N = 5), luminescence was first visible in the neck on the side of the injected ear, and in the abdominal cavity at 24 h postinfection ( Figure 5A ). Histologic analysis established the source of the light in the neck; the neck signal came from the lymph nodes draining the injected ear (data not shown). At 40 h post-infection, organs in the abdominal cavity, including the pancreas and the liver were highly luminescent. All mice succumbed to infection by 69 h post-infection, a survival time significantly longer than after i.p. inoculation (P,0.025). Luminescent virus inoculated intranasally was already detected 24 h post-infection in the abdomen. This mode of inoculation caused an interstitial pneumonia that initiated as a distinctive luminescence signal in the lungs from 48 h post-infection onwards ( Figure 5B ). Mice infected intranasally (N = 5) survived significantly longer than after i.p. inoculation (P,0.0047); all were dead by 69 h post-infection.