A survey of more than 800 people in northern Victoria has found the Japanese encephalitis virus has infected more people than first thought, as the vaccination eligibility criteria against this virus continue to expand.
The serosurvey, which asked participants to complete a questionnaire and give a blood sample, found approximately 1 in 30 participants had evidence of having a prior Japanese encephalitis infection.
This suggests many more people may have been infected than the number of ill or symptomatic cases reported – 13 – in last year’s mosquito season.
Participants who showed evidence of prior infection were aged between 25 and 90, with a median age of 73, and a majority were male.
They were identified in all three regions that took part in the survey – Loddon Mallee, Goulburn Valley, and Ovens Murray.
“By finding more cases than we were previously aware of, this important research reinforces the risk to all in the community that mosquito-borne diseases pose – especially in light of recent flood activity,” Victoria’s Deputy Chief Health Officer Associate Professor Deborah Friedman said.
Sensible step
“There are sensible steps people can take to avoid mosquito bites. Wear long, loose-fitting, light-coloured clothing, use insect repellents, clear stagnant water around homes or properties, and avoid the outdoors when mosquitoes are observed, especially at dusk and dawn.”
Seven new areas
The eligibility criteria for vaccination against Japanese encephalitis has also been extended to seven new local government areas: Greater Bendigo, Northern Grampians, Hindmarsh, Horsham, Buloke, Yarriambiack and West Wimmera.
Vaccination remains free of charge for those most at risk. The serosurvey was run by the Department of Health in collaboration with local public health units and the Victorian Infectious Diseases Reference Laboratory.
Victoria has recorded one case of Japanese encephalitis in humans this mosquito season, indicating the virus continues to circulate in parts of Victoria.
While vaccination against Japanese encephalitis is available, there are a number of mosquito-borne diseases known to be circulating in Victoria – such as Murray Valley encephalitis and West Nile (Kunjin) virus – for which no vaccine is available.
That’s why avoiding mosquito bites is the most important measure to protect against mosquito-borne diseases. The Department of Health provides funding and direction to councils in areas at high-risk for mosquito-borne diseases to undertake both mosquito surveillance and mosquito control activities.
For more information, see: https://www.youtube.com/watch?v=ecGoD2EUTO0 More tips on protecting yourself from mosquito-borne diseases are also available on Better Health Channel.
This article appeared in The Buloke Times, 7 March 2023.
