“The first case was in a Darwin resident who caught the illness while holidaying in Vietnam, while the second case was acquired from the first," Dr Peter Markey, acting director of the Centre for Disease Control, said.

"This means there is likely to be people with symptoms of measles in Darwin from today for the next three weeks.”

Health officials said the first case attended the new Palmerston Regional Hospital on February 15 and 17 and people exposed at that time who are not immune may have symptoms over the next few days.

The second person was at the Top End Medical Centre in Stuart Park on Sunday, March 3 and Tuesday, March 5 March and then Palmerston Regional Hospital on March 5.

Those exposed at this time who are not immune may get symptoms from March 10.

The Centre for Disease Control is contacting people who may have had contact with these cases to provide information and offer preventive treatment or booster immunisation as appropriate.

“To be immune to measles you need to have had measles previously or have had two doses of the measles-containing vaccine, known as the Measles, Mumps and Rubella (MMR) vaccine. The vaccine is given as part of the routine national vaccination schedule at 12 months and at 18 months, but people born between 1966 and 1996 may have only had one dose as a child and should check their record. If uncertain, an extra vaccine is recommended,” Dr Markey said.

“It is reassuring that we have a well-vaccinated population, however this is a timely reminder for all people to review their immunisation status and attend their local community care centre or their GP for their free immunisation if required.”

Measles is a very contagious viral illness that is spread between people through coughing and sneezing. It can be caught in public places such as shopping centres and waiting rooms.

The symptoms of measles are fever, cough, runny nose and sore eyes, which usually occur 7-10 days after exposure to a case, followed a few days later by a red blotchy rash which often starts on the face and then becomes widespread over the body.

Up to one third of people infected with measles will experience a complication.

Complications are more common in young children and adults and include ear infections, diarrhoea, pneumonia and encephalitis (swelling of the brain) and may require hospitalisation.

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