A measles outbreak in Japan and Taiwan has put thousands of people in quarantine and forced tourists to put off visits to southern Japan, media reports said.

More than 3,500 people in the southern Taiwanese city of Kaohsiung have been quarantined and are being monitored by the island's health authorities after coming into contact with infected crew members of budget carrier Tigerair Taiwan, local media reported.

A further 980 are being monitored following the discovery of an infection cluster at a major hospital in Taoyuan city, just outside Taipei.

The outbreak has been traced to a 30-year-old male flight attendant with Tigerair Taiwan, said the semi-official Central News Agency.

He caught the highly contagious virus in Thailand in March and the infection was confirmed on March 29. But by then he had infected two cabin crew colleagues during a Tigerair Taiwan flight to the southern Japanese prefecture of Okinawa. The latter two - a 34-year-old man and a 28-year-old woman - continued working until they fell seriously ill and were diagnosed with measles early this month, Central News Agency said.

As of yesterday, at least 22 people in Taiwan have been confirmed to have measles, which causes high fever and rashes, and can be fatal for young children.

The disease has since spread in Okinawa, and appeared to be heading north, with cases confirmed in the central city of Nagoya. The source of the outbreak is the same person - the Tigerair Taiwan flight attendant, Taiwan media said. The man had flown to the prefecture for a holiday between March 17 and 19.

As of April 20, a total of 67 patients had been confirmed to have contracted the disease, reported Japanese media. They included people who had come in contact with the tourist, as well as their family members and colleagues, the Asahi Shimbun said.

Some schools in Okinawa have cancelled classes.

More than 170 people have cancelled trips to Okinawa ahead of the spring holiday season, said public broadcaster NHK. In Nagoya, a resident who had visited Okinawa was diagnosed on April 11, and a nurse at a hospital was confirmed to be infected 10 days later.

Japan's Health Ministry is urging the public to get vaccinated ahead of the country's Golden Week travel peak next week, the Asahi said.

In Hong Kong, the Centre for Health Protection said it was monitoring the situation, South China Morning Post reported. It urged travellers to remain vigilant, and noted that vaccination was the best way of preventing the disease, which has a 21-day incubation period.