National approach required to quell Japanese encephalitis virus

Australia’s Acting Chief Medical Officer, Dr Sonya Bennett, has officially declared the unfolding situation in Australia concerning the Japanese encephalitis virus (JEV) a Communicable Disease Incident of National Significance.

The declaration was made under the Emergency Response Plan for Communicable Disease Incidents of National Significance, in consultation with the Australian Health Protection Principal Committee, and followed a briefing with the National Security Committee of Cabinet on the unfolding situation regarding JEV.

JEV is a mosquito-borne viral disease that mostly occurs in pigs and horses, but can cause disease in people and, rarely, other animals. Pigs are the focus from a human health perspective as they can infect mosquitoes that can then infect humans; this is not the case with horses. The disease is also not transmissible between humans.

The vast majority of infected people will show mild or no symptoms at all, but less than 1% of people infected may develop a serious illness such as encephalitis (inflammation of the brain) and experience symptoms including neck stiffness, severe headache and coma, and, more rarely, permanent neurological complications or death.

On Thursday, 3 March, Queensland officials confirmed a human case of JEV in that state. The case had recently travelled in regional parts of the state’s south and is being treated in a Brisbane hospital. Since then, JEV had been confirmed at piggeries across NSW, South Australia, Queensland and Victoria, while cases of encephalitis have been found in multiple states.

The Australian Government has said it will work closely with states and territories to educate the community about JEV, what precautions people should take and symptoms to be aware of. The government will also work closely with the states and territories to support the distribution of vaccine doses to at-risk population groups.

“I have declared the JEV situation a Communicable Disease Incident of National Significance after determining a national approach is required in relation to coordination of health policy, interventions and public messaging,” Dr Bennett said.

“A national working group of communicable disease, vaccine and arbovirus experts has been established to support the response, including mosquito surveillance and control measures and identification of those at direct risk, and for the rollout of vaccines.

“The Australian Government’s health and agriculture departments are working very closely with their state government counterparts to ensure a swift and coordinated response.”

Dr Marianne Gale, NSW Acting Chief Health Officer, said the best way to avoid infection is to avoid being bitten by mosquitoes, which are most active between dusk and dawn.

“NSW Health is cautioning people undertaking outdoor activities such as camping and fishing to carefully consider their plans,” Dr Gale said. “This is especially important for people planning activities near waterways or where mosquitoes are present, particularly the Murray River and its branches.

“People should be particularly vigilant given the recent wet weather conditions, which have led to very high mosquito numbers that may increase further in the coming days and weeks.”

In addition to staying indoors during peak mosquito times, other preventative measures include wearing long sleeves, pants, shoes and socks outdoors; applying insect repellent to all areas of exposed skin; using mosquito coils and other devices that release insecticides in combination with topical insect repellents; and reducing water-holding containers around the home where mosquitoes could breed.

Australia’s Chief Veterinary Officer, Dr Mark Schipp, meanwhile advised on how animal owners can monitor for signs of JEV.

“The key signs to look out for in pigs are stillborn or weak piglets, some with an impaired nervous system,” Dr Schipp said. “Piglets can develop encephalitis or wasting, depression or hindlimb paralysis. Adult sows do not typically show signs of disease.

“In horses, many cases show no signs of the disease. Some animals may show signs of elevated temperature, jaundice, lethargy or anorexia. Other signs may include lack of coordination, difficulty swallowing, impaired vision or overexcitement.

“People working with pigs, even if they’re only a backyard pet or a small herd, should take steps to control mosquitoes, as well as continuing to practise good biosecurity.

“Horse owners can also put measures in place to help their horses avoid mosquito bites, including using hooded rugs, fly masks and applying a safe insect repellent.

“If you suspect an animal is showing signs of the disease, you must report it via your local veterinarian or the national Emergency Animal Disease Watch Hotline on 1800 675 888.”

Image credit: ©stock.adobe.com/au/dusanpetkovic1

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