Health official warns of mosquito risk

VICTORIA’S deputy chief health officer has warned heavy rainfall and flooding has increased mosquito breeding and that already high numbers are expected to increase.

Associate Professor Deborah Friedman forecast greater mosquito biting in coming weeks and urged people to take steps to avoid the risk.

“Anyone is potentially at risk of being bitten by mosquitoes, and while most bites only cause minor swelling and irritation, an infected mosquito can transmit potentially serious diseases,” she said.

“Taking measures to avoid mosquito bites is therefore a critical step to protect against diseases.”

The alert follows a warning earlier this month that case numbers of the flesh-eating Buruli ulcer, also commonly known as the Bairnsdale ulcer, were being detected at above average rates in greater Geelong and were also showing up on the Bellarine and the Surf Coast.

Geelong case numbers have reached record levels with 40 detected this year, out of 266 across Victoria.

The skin disease is linked to areas where mosquitoes, possums and soil are frequently found to be carrying it.

“We are monitoring key sites where there has been a reported increase in mosquitos in areas such as Eastern Park, Barwon Heads and Ocean Grove,” City of Greater Geelong director of city services Guy Wilson-Browne said.

“The persistent rain means we’re likely to see higher mosquito numbers than in previous years and unfortunately the rain also limits the effectiveness of the treatments we have applied.”

Increasing case numbers of Buruli ulcer align with the rise of mosquito borne diseases like Ross River virus, that last year hit record highs across the Greater Geelong and Surf Coast regions.

Geelong recorded 119 cases in 2021, double its previous peak of 66 in 2017.

Professor Friedman said that while endemic across the state, the diseases occur more frequently in regional riverine and coastal areas.

“More rarely, mosquitoes can transmit Japanese encephalitis virus, Kunjin virus and Murray Valley encephalitis virus, which can cause serious illness,” she said.

“Aside from Japanese encephalitis, vaccines are not available for these other mosquito-borne diseases. Importantly there is no vaccine currently available to protect against Ross River Virus disease.”