A traveller infected with measles has prompted a health warning on Saturday.

The confirmed measles case visited tourism hotspots in Alice Springs and Darwin between July 17 and 23, NT Health said.

Airports, an art gallery, and organised tours of the Litchfield National Park were all on the itinerary — and anyone who visited the same places about the same time is now urged to monitor for symptoms.

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It is believed the infected traveller contracted measles while overseas.

“Measles is a highly infectious viral illness, which can cause serious disease,” NT Health said.

The illness is now uncommon in Australia because of high levels of immunisation, and is preventable with two doses of a measles-containing vaccine.

Symptoms — which begin as fever, cough, runny nose, sore eyes and rashes — begin from seven days after exposure, but can also emerge as late as 21 days after exposure.

The infection is spread by breathing in airborne droplets from the coughs or sneezes of infected individuals, and a third of people who catch the measles will experience a complication.

Complications, such as ear infections, pneumonia, and diarrhoea, can all require hospitalisation, and about one in 1000 patients can develop encephalitis, which is an infection of the brain.

Hotspots under alert

On Thursday, July 17, the infected traveller did an all-day tour through Litchfield National Park with Ethical Adventures.

On Friday, July 18, they departed for an AAPT Kings Jabiru tour, and returned the next day.

They stayed in the Mercure Kakadu Crocodile Hotel, based in the Jabiru township of Kakadu National Park, and dined at the restaurant there between 6pm and 8pm.

On Sunday, July 20, the infected traveller visited the Museum and Art Gallery of the Northern Territory from 1pm to 3pm.

They also visited the Darwin International Airport, and were in the check-in and departures area between 3.30pm and 4pm.

They boarded Qantas flight QF1960 from Darwin to Alice Springs, and were in the Alice Springs Airport arrivals area between 7pm and 7.30pm.

The infected traveller’s movements have not been released for the two days which followed.

On Wednesday, July 23, the traveller visited Alice Springs Airport again, and were in the check-in and departures area between 12pm and 12.30pm.

They boarded Air North flight TL361 from Alice Springs to Cairns.