Our experts tackle JEV

GEELONG scientists from CSIRO’s Australian Centre for Disease Preparedness are providing expert advice and support amid the outbreak of Japanese encephalitis virus.

JEV is a mosquito-borne virus that can cause encephalitis – inflammation of the brain – in about 1 per cent of cases that become infected. It can be fatal.

So far it has claimed the lives of two men and infected multiple people in NSW, Queensland, Victoria and South Australia.

But authorities do not know how it arrived here.

Last week Health Minister Greg Hunt announced a $69m funding boost to combat the virus.

“We have 15,000 vaccines in the country and we are purchasing an extra 130,000 based on the public health advice,” Mr Hunt said.

Most people who contract JEV will have no or very mild symptoms and fully recover.

Japanese encephalitis expert at the ACDP, David Williams, said people and animals could contract JEV when they were bitten by an infected mosquito.

It cannot be transmitted directly from an infected person to an uninfected person.

Dr Williams said the ACDP, located in Geelong, was a nationally recognised reference laboratory for infections transmitted by insects.

“Our scientists have been heavily involved in diagnostics testing for affected states, particularly for testing piggeries suspected of being infected,” he said.

“As part of diagnostic support, ACDP scientists have provided information and advice to animal and public health laboratories on laboratory diagnostics.

“This has included testing guidelines and materials to assist accurate diagnostic testing.

“ACDP also provided the first genome sequence of the outbreak JE virus strain that allowed diagnostic laboratories to check that their existing PCR tests would be accurate and aid the design of new tests if required.”

He said ACDP scientists had also been advising government and animal health working groups involved in outbreak response.

Dr Williams said JEV was detected in piggeries in southern Queensland, NSW, Victoria and South Australia in late February and March, which was associated with higher-than-normal levels of stillborn and weak piglets.

“The initial infections are believed to have occurred towards the end of 2021,” he said.

Dr Williams said early last year there had been a fatal human case in the Tiwi Islands off the coast of the Northern Territory – the first locally acquired human case in Australia since 1998.

This caused alarm bells among public and animal health authorities, he said.

“The 2021 case was found to be caused by a variant of JE virus that had rarely been detected before and is mainly found in Indonesia,” Dr Williams said.

“How the virus subsequently spread to the southeast of Australia is not known with certainty, but it is thought that the most likely mechanism was via infected waterbirds that migrated from northern Australia to the wetlands and waterways of southeastern Australia.

“From there, local mosquito populations are likely to have become infected by feeding on infected waterbirds, before spreading the virus to pigs and people.”