Two Sydney babies too young to be vaccinated infected with measles

Two babies have been diagnosed with measles in Sydney with health authorities saying they probably caught the highly infectious disease locally.

Two infants with measles probably acquired the infection in Sydney, health authorities say.

NSW Health on Tuesday issued its 15th measles warning for the year after two babies too young to be vaccinated became infected in mid-March.

An eight-month-old likely contracted the disease in the Haymarket area and was infectious while visiting a Strathfield Korean restaurant on March 26, a Hurstville cafe on March 27 and St George hospital emergency department on March 30.

The other baby, aged 11 months, likely caught the disease in Eastwood before visiting shopping centres in Eastwood, Castle Hill and Kellyville in the last week of March.

NSW recorded 46 measles cases between January 2017 and November 2018.

Five measles cases confirmed in Perth's south. Source: AAP

Some 28 cases have been recorded in the four months since.

The health department says maintaining high rates of measles immunisation within the community reduces the risk of measles being imported by travellers and then spread locally.

"Herd immunity provides protection to those unable to be vaccinated such as infants and people with weakened immune systems," NSW Health communicable diseases director Dr Vicky Sheppeard said in a statement.

The measles vaccine is free for anyone born since 1966.