We investigated whether
chloroquine can prevent
hantavirus infection and disease in vitro and in vivo, using the Hantaan virus newborn C57BL/6 mice model and the Syrian hamster model for Andes virus. In vitro
antiviral experiments were performed using Vero E6 cells, and Old World and New World hantavirus species. Hantavirus
RNA was detected using quantitative RT-PCR. For all hantavirus species tested, results indicate that the IC50 of
chloroquine (mean 10.2 ± 1.43 μM) is significantly lower than the CC50 (mean 260 ± 2.52 μM) yielding an overall selectivity index of 25.5. We also investigated the potential of
chloroquine to prevent death in newborn mice after Hantaan virus
infection and its
antiviral effect in the hantavirus Syrian hamster model. For this purpose, C57Bl/6 mother mice were treated subcutaneously with daily doses of
chloroquine. Subsequently, 1-day-old suckling mice were inoculated intracerebrally with 5 x 102 Hantaan virus particles. In litters of untreated mothers, none of the pups survived challenge. The highest survival rate (72.7% of pups) was found when mother mice were administered a concentration of 10 mg/kg
chloroquine. Survival rates declined in a dose-dependent manner, with 47.6% survival when treated with 5 mg/kg
chloroquine, and 4.2% when treated with 1 mg/kg
chloroquine. Assessing the
antiviral therapeutic and prophylactic effect of
chloroquine in the Syrian hamster model was done using two different administration routes (intraperitoneally and subcutaneously using an osmotic pump system). Evaluating the prophylactic effect, a delay in onset of disease was noted and for the osmotic pump, 60% survival was observed. Our results show that
chloroquine can be highly effective against Hantaan virus
infection in newborn mice and against Andes virus in Syrian hamsters.