Infectious disease experts have warned widespread flooding and record rainfall, driven by a third consecutive La Nina, could result in a major outbreak of mosquito-borne viruses including Japanese encephalitis this summer.
Research led by the QIMR Berghofer Medical Research Institute in Brisbane and documented in the most recent edition of Clinical Infectious Diseases, suggests up to 750,000 Australians could be exposed to the Japanese encephalitis virus. People living near piggeries and close to populations of wading birds are particularly at risk.
QIMR Berghofer’s Associate Professor and senior author of the paper Greg Devine said infectious disease experts are extremely concerned about further outbreaks of Japanese encephalitis this summer.
The major carrier of the disease is mentioned as the ‘Culex annulirostris’ mosquito species, which is capable of dispersing more than four kilometres per day.
“The wet and warm weather creates the right environment for mosquitoes to proliferate and may encourage changes in the distributions of the wild birds that maintain the virus during Australia’s winter months,” he said.
“Most Australians have not been exposed to the virus before, so they have no immunity. We are urging people to take precautions. The best protection is vaccination, but currently that’s not available to everyone. The next best protective measure is to avoid being bitten by a mosquito.”
The NSW Arbovirus Surveillance and Mosquito Monitoring Program, which commenced early October, has already reported ‘high’ mosquito counts for Corowa in the week ending October 22.
As mosquito numbers boom, Murrumbidgee Local Health District (MLHD) is encouraging local residents who meet eligibility criteria to vaccinate now against Japanese encephalitis virus to be protected in time for the summer mosquito season.
Acting Director Public Health, Alison Nikitas is urging people who meet the eligibility criteria for vaccination to speak to their local doctor about the risks of mosquito-borne viruses and to discuss with their doctor if they are eligible for a JE vaccine.
“It is particularly important to vaccinate now if you are eligible because it takes up to four weeks following vaccination to develop a protective immune response to the JE virus,” Ms Nikitas said.
The eligibility criteria for access to a free vaccination has been expanded to include all eligible Local Government Areas involved in the clean-up of stagnant waters after the recent floods, or if their living conditions place them at increased risk of exposure to mosquitoes.
In NSW, the JEV vaccine is recommended for those who live in one of the following Local Government Areas: Albury, Balranald, Berrigan, Carrathool, Dubbo Regional, Edward River, Federation, Goulburn Mulwaree, Greater Hume, Griffith, Hay Shire, Lockhart, Murray River, Murrumbidgee, Temora and Wentworth.
AND are either:
1.aged 50 years or older who spend four or more hours per day outdoors or,
2.are engaged in the recovery efforts (clean up) of stagnant waters following floods or,
3.are living in conditions that place them at increased risk of exposure to mosquitoes.
The vaccine expansion has been welcomed by Corowa’s Jackie Monk. Ms Monk’s husband David Kiefel tragically died after contracting the virus earlier this year.
“It’s great news, but please open it to everyone. Everyone in this area should have access to the vaccine,” Ms Monk said.
“The stagnant water lying around this area is a huge concern. That water will take a very long time to dry out.”
Ms Monk met with Member for Benambra Bill Tilley in Wahgunyah last week where they discussed vaccine eligibility and concerns about a Japanese Encephalitis outbreak this summer.
While fewer than 1 per cent of Japanese encephalitis cases are believed to be symptomatic, for those developing symptoms, the fatality rate is estimated at around 30 per cent, with around half of survivors said to have long-term neurological damage.
There are two vaccinations available in Australia that protect against the disease, but neither is currently covered under the National Immunisation Program and aren’t funded by states and territories.
“It’s important we get the message out there to the whole community, particularly while we are significantly impacted by low level laying water, that this is a real crisis,” Mr Tilley told the Free Press.
“We’ve got manufacturers in Australia who can make the vaccine and have it more accessible to residents who live in the country.
“Whether it’s camping, golfing, fishing, local sports or working, we all spend a significant time outdoors in regional Victoria.
“I’m not suggesting for a moment we mandate the vaccine. But if you’re living and working outdoors, you’re at risk.
“I’ve written to the Chief Health Officer and we haven’t had a response. We need to be prepared for this. Around the river system, everyone is at risk and so we ask the government to make the vaccine accessible to us all. We don’t want to see more people getting sick.”
JE vaccine is available through local General Practitioners (GPs). People who meet the above criteria should make an appointment with their doctor and let them know it is for the JE vaccine. GPs may require a few days’ notice so they can order the vaccine.
The vaccine is also recommended for people travelling to some overseas countries, but these vaccines are available for purchase on the private market.
You can protect yourself by:
•wearing light, loose-fitting long-sleeved shirts, long pants and covered footwear and socks, especially around dusk and dawn
•applying repellent to all areas of exposed skin, using repellents that contain DEET, picaridin, or oil of lemon eucalyptus
•re-applying repellent regularly, particularly after swimming, being sure to always apply sunscreen first and then apply repellent
•avoid going outdoors at dawn and dusk, unless wearing mosquito repellents and protective clothing
•covering openings such as windows and doors with insect screens and checking there are no have gaps in them
•removing items that might collect water (such as old tyres, empty pots) outside your house where mosquitoes can breed
•improving drainage on your property so that water does not become stagnant
•using insecticide sprays, vapour dispensing units and mosquito coils to repel mosquitos (mosquito coils should only be used outside).