Chloroquine inhibits Hendra virus: study

The common malaria drug chloroquine is able to inhibit infection by Hendra and Nipah viruses, an international team of researchers has found.

The two henipaviruses, which are harboured by fruit bats, emerged as zoonotic pathogens only recently. Hendra has killed three people and many horses in Australia since its emergence in 1994.

Nipah virus has killed several hundred people in south-east Asia and has recently been found to be spread from human to human. Both viruses have a very high mortality rate.

In a study co-authored by the CSIRO’s Bruce Mungall and published in the Journal of Virology, the researchers developed a high-throughput screening assay for inhibitors of infection based on envelope glycoprotein pseudotypes.

They found several effective molecules, including chloroquine. The drug does not prevent the viruses from entering the cell but it appears it is able to block the action of cathepsin L, a cellular enzyme that is essential for the maturation of newly budding virions.

The researchers write that given the established safety profile of chloroquine in humans, consideration should be given using it to treat henipaviruses.

There is also the possibility of using it for Ebola virus and several others, as these viruses also depend on capethsin L for processing viral fusion proteins.