Teenagers preparing to head overseas to celebrate schoolies are being urged to pack the mozzie spray and visit their GP or risk catching an infectious disease.
Those travelling to Bali or Fiji are particularly at risk, with hepatitis A and measles still a common disease in Asia, NSW Health says.
More than 100 unvaccinated travellers develop measles or hepatitis A every year on return to Australia, it said.
Rabies infection is another risk for teenagers travelling to Asian countries, especially if they are planning to visit monkey forests.
"Rabies is almost invariably fatal, so if schoolies do get a bite or scratch while in Bali they should wash the wound thoroughly and seek immediate medical attention," director of the communicable disease branch, Dr Vicky Sheppeard said.
She urged teenagers to get their free measles vaccine before they travelled if they had not already had two documented doses during their life.
Schoolies have also been warned about the dangers of contracting mosquito-borne infections, including dengue and Ross River virus.
"Make sure you pack an effective insect repellent, and apply it regularly, particularly in the evening," Dr Sheppeard said.
© AAP 2018