Viremia in North American Mammals and Birds after Experimental Infection with Chikungunya Viruses

Chikungunya virus (CHIKV) is an arthropod-borne virus, which is known to cause severe disease only in humans. To investigate its potential zoonotic host range and evaluate reservoir competence among these hosts, experimental infections were performed on individuals from nine avian and 12 mammalian species representing both domestic and wild animals common to North America. Hamsters and inbred mice have previously been shown to develop viremia after inoculation with CHIKV and were used as positive controls for infection. Aside from big brown bats (Eptesicus fuscus), none of the mammals or birds developed detectable viremia or overt clinical disease. However, most mammals and a smaller proportion of birds developed neutralizing antibody responses to CHIKV. On the basis of these results, it seems unlikely that CHIKV poses a significant health threat to most domestic animals or wildlife and that the species examined do not likely contribute to natural transmission cycles. Additional studies should further evaluate bats and wild rodents as potential reservoir hosts for CHIKV transmission during human epidemics.