Measles, polio detected as authorities urge caution

Travellers are being warned to monitor for symptoms after a new case of measles was detected after a person was exposed to the disease on an international flight.

The contracted case was reported in Victoria after the person was exposed while on VietJet Air flight VJ083 which arrived in Brisbane on December 4, Victoria's Acting Chief Health Officer Christian McGrath said.

It's the second case detected in Victoria in December after another traveller tested positive in Queensland, having transited through Melbourne Airport while they were infectious.

People who have attended Melbourne Airport on about 9.24pm to 10.30pm on December 8 and between 5am and 7.25am on December 9 are being urged to monitor for symptoms. These can include a fever, cough, sore or red eyes, runny nose, and feeling generally unwell, followed by a red bumpy rash.

An infected person was also traced to the Woolworths store at The Links Shopping Centre in Oakleigh South, Friendly Grocer and Pastry Supreme Bakehouse in Bentleigh East on December 19 between 11.27am and 12.55pm.

Anyone who attended any of the exposure sites on the specific dates and times should monitor for symptoms.

The measles case comes as Chief Health Officer Clare Looker revealed waste water testing detected poliovirus in the Melbourne metropolitan area.

The poliovirus type 2 case was detected on December 2 and appears to be derived from someone who may have received a vaccine.

"This detection is likely linked to someone who received a live polio vaccine overseas and has continued to shed the virus since arriving in Victoria," Dr Looker said.

"The presence of the virus in wastewater poses no risk to Melbourne residents, as the sewage is thoroughly treated."

Australia uses an inactivated polio vaccine, preventing the disease from multiplying inside the body and it cannot cause polio, be detected in the bowel or sewerage.

Polio is a highly contagious viral infection that can cause paralysis and death.

Children and adults who have not been fully vaccinated against polio are at greatest risk if exposed to an infected person, and the best protection against polio is through immunisation, Dr Looker said.

There has been an increase in measles cases in returned travellers across Australia in recent weeks amid growing outbreaks internationally, including Vietnam.

Fifteen measles cases have been reported among Victorians since the start of the year.

Unvaccinated babies are at high risk of contracting the virus while infants, pregnant women and people with weakened immune systems are at an increased risk of serious complications, including pneumonia and brain inflammation.

Symptoms can develop up to 18 days after exposure with people warned to be vigilant as initial symptoms may be similar to COVID-19 or the flu.

People are potentially infectious from 24 hours before experiencing symptoms until four days after the rash appears.

The virus can spread through airborne droplets or contact with nose or throat secretions and contaminated surfaces and objects, lasting for up to two hours in the environment.

Outbreaks of measles have been reported in Asia, Africa, Europe and the UK, the Middle East and the US.