Why should I care about Japanese Encephalitis?

Japanese Encephalitis is a virus that spreads through mosquito bites. Unsurprisingly, pig farms are helping spread this virus rapidly down the east coast of Australia. Let's dive into what Japanese Encephalitis is, how it came to Australia, how it's linked to pig farming, and what you can do to help prevent future outbreaks.

What is Japanese Encephalitis?

Most people infected with Japanese Encephalitis will be asymptomatic, but approximately 1 out of 100 cases will experience severe brain inflammation, leading to permanent disability and even death. After being bitten, symptoms can take 6 to 16 days to show in people. Other species have been reported to display signs of infection, however, the virus typically only affects humans, pigs, ducks, and horses. 

Mosquitos brought Japanese Encephalitis here, but how is it spreading so rapidly?

How the virus made its way to Australia is not fully known, however, experts believe mosquitos from Papua New Guinea brought the virus over with the help of long-range wind, allowing them to travel 100-200kms. Once in Northern Australia, the migration of infected waterbirds spread the virus down the East coast. Local mosquitos then feed on the infected birds before spreading it to pigs and people.

Why is it spreading through piggeries?

The virus exists in a transmission cycle between mosquitoes, pigs and/or water birds (enzootic cycle). Humans and horses are classified as "dead-hosts", as their blood often does not contain enough of the virus to be spread by other mosquitos. Pigs, however, produce high amounts of the virus, which can then be transmitted to others.

The issue is that piggeries are wet environments, and the effluent collection systems can become breeding grounds for mosquitos (Australian pork limited). When a mosquito bites an infected pig it can then transfer the virus to another pig, multiplying and spreading the virus. These mosquitos then infect people working at the piggeries or those who live nearby. 

Additionally, infected pigs can spread the virus through their saliva and nasal secretions, and sows can become infected from infected semen.

In 1995, the Australian government banned the importation of pig semen due to disease and virus concerns. Despite this, piggeries have been caught illegally smuggling pig semen from overseas. This is incredibly dangerous, as it can bring in new diseases and viruses.

If undetected, infected pigs are transported to various slaughterhouses and mosquitos in that area will continue to be spread.

Japanese Encephalitis has now been detected in 28 piggeries across Queensland, New South Wales, Victoria, and South Australia.

Signs of infections aren't immediately noticeable

Infections at piggeries may take weeks before it is noticed. Adult sows do not typically display any obvious signs of disease. If they become infected before 60-70 days of pregnancy, they often have abortions, give birth to stillborn/mummified babies, or weak piglets who have neurological issues.

Infected boars can have reduced fertility and swollen, congested testicles.

Are there any other risks?

Despite The Department of Health warning people to stay away from areas with high mosquito numbers, such as lakes, Premier Daniel Andrews is still allowing the Victorian duck hunting season to continue. This means we could see a spike in the number of human cases of Japanese Encephalitis and the need for more tax-payer money* to be used for vaccinations. 

*The Australian Government has given $69 million in response to the Japanese Encephalitis outbreak, for vaccines, control programs, future modelling, and emergency response. 

What can we do?

As consumers, we hold the power to make real change because our food preferences drive the demand and influence the current food system. By opting for plant-based products, we can help reduce the demand and need for animal agriculture, and thus limit the spread and impact of diseases and viruses. How is animal agriculture linked to diseases and viruses? Animal agriculture keeps animals in unnatural and confined conditions, where they are forced to live in their waste or among sick individuals. These conditions create the perfect breeding ground for diseases and viruses, helping them spread, and in some cases, mutate becoming more deadly and infectious to people. 

How to protect yourself

To avoid being bitten, wear long-sleeved shirts and long pants, avoid areas with high mosquito numbers (areas with stagnant bodies of water), apply mosquito repellent, and regularly replace or empty stagnant water sources.

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