Victoria’s worsening flesh-eating ulcer epidemic has spread to Geelong and the Surf Coast, raising fears the number of victims could increase over the summer months.

Ten new cases of buruli ulcer have been reported in the Geelong suburb of Belmont and the nearby town of Aireys Inlet on the south-west coast this year.

Scientists believe mosquitoes are are part of the transmission chain that connects the Buruli ulcer to humans. Credit:Reuters

On Thursday, the Health Department confirmed it had now added both areas to the ulcer's official transmission area.

Until now, the outbreak had seemed to be heading north along the Mornington Peninsula towards Melbourne – and away from Geelong, Victoria's second-largest city.