Crimean-Congo hemorrhagic fever virus infection is lethal for adult type I interferon receptor-knockout mice.

Crimean-Congo hemorrhagic fever virus (CCHFV) poses a great threat to public health due to its high mortality, transmission and geographical distribution. To date, there is no vaccine or specific treatment available and the knowledge regarding its pathogenesis is highly limited. Using a small-animal model system, this study showed that adult mice missing the type I interferon (IFN) receptor (IFNAR(-/-)) were susceptible to CCHFV and developed an acute disease with fatal outcome. In contrast, infection of wild-type mice (129 Sv/Ew) was asymptomatic. Viral RNA was found in all analysed organs of the infected mice, but the amount of CCHFV RNA was significantly higher in the IFNAR(-/-) mice than in the wild-type mice. Furthermore, the liver of IFNAR(-/-) mice was enlarged significantly, showing that IFN is important for limiting virus spread and protecting against liver damage in mice.