Lethal infection of embryonated chicken eggs by Hazara virus, a model for Crimean-Congo hemorrhagic fever virus.

Hazara virus (HAZV) is a member of the genus Orthonairovirus of the family Nairoviridae. HAZV is closely related to Crimean-Congo hemorrhagic fever virus but differs in that it is non-pathogenic to humans. To establish an infection model system, we tested whether embryonated chicken eggs, which are classically used for evaluating viral pathogenicity, are susceptible to HAZV infection. We demonstrated that HAZV replicates well in embryonated chicken eggs and kills 100% of the embryos. This can be a valuable tool to evaluate the lethality of nairoviruses in a biosafety level 2 laboratory.