Why there are more cases of measles in Australia now?

Several cases of measles have been reported in Australia recently. This year in NSW alone 23 cases have been reported. There has been reports of measles in some areas of Queensland including the Gold Coast. Why there is a surge in the number of cases in the recent years? What measures can be taken in this circumstance? Dr Reeshma Pattan, paediatrician in Melbourne explains.

Source: AAP