Figure 1. Chikungunya virus (CHIKV) induced disease signs.

A. Pictures of the hind limbs of mock- and CHIKV-infected animals. Chikungunya virus infection induced severe hind limb disease in new born mice. 2–3 day old mice inoculated with 10⁶ PFU (50 ul) of CHIKV by subcutaneous injection in the loose fold of skin on the back of the animal developed peak clinical signs on 8 day post inoculation whereas mock-infected group injected with uninfected tissue culture supernatant remained healthy. B. Mice were scored for the development of hind limb dysfunction and disease based on the following scale: 0, no disease signs; 1, ruffled fur; 2, mild hind limb weakness; 3, moderate hind limb weakness; 4, severe hind limb weakness and dragging and 5, moribund. Each data point represents the arithmetic mean ± SD for eight animals. Data is representative of three independent experiments.