Mosquito activity has increased in the Hunter, with people being urged to protect themselves against mosquito bites.
The past month has seen 10 people infected with the Ross River or Bahmah viruses.
Public Health Physician Dr David Durrheim says the recent rain has provided ideal breeding grounds for mosquitoes.
"[At] this time of the year, the environmental conditions are perfect for mosquito breeding and survival.
"Mosquitoes need [a] moist environment to lay their eggs and then obviously when the adults hatch out, they need sufficiently warm conditions to survive long enough to become infected themselves to pass the infection onto people," Dr Durrheim said.
