MDK and infection: Mice inoculated with six viruses, including CK/VN/1180/06, DK/VN/31/07, DK/VN/34/07, DK/VN/43/07, CK/VN/45/07, and MDK/VN/46/07, lost over 20% of their body weight and died within 10 days of infection (Figure 3 A, B, and Table 2).